As will soon become apparent, I strongly disagree with the majority’s analysis—an analysis that should be terrifying to any person who drives on a freeway.
As the parties and the trial court recognized, this case poses a relatively straightforward question. Is a freeway overpass a public forum that demonstrators can use to communicate their message to freeway motorists passing below?
In declining to decide this question, the majority takes a wrong turn that in effect invites groups or individuals to demonstrate on freeway overpasses, leaving them and the California Highway Patrol with the burden of litigating over the use of freeway overpasses case by case, overpass by overpass, throughout the state—with the outcome depending on how much traffic congestion that a particular demonstration causes. In other words, the parties will be obligated to hit the road again, through future litigation, in an effort to obtain judicial answers to the questions they pose.
And the majority’s decision will burden freeway motorists with the danger that its approach will create. After all, the purpose of demonstrating on a freeway overpass is to cause freeway motorists to take their eyes and attention off driving and to focus, instead, on the signs and photographs displayed by the demonstrators—and even to cause motorists to remain distracted as they ponder, rejoice, or fume about the message while driving on. Nevertheless, the majority suggests that authorities must wait and see whether traffic congestion and dangerous conditions actually develop.
I refuse to travel down this road since it is far too dangerous and because the majority’s analysis is inconsistent with the law and common sense. Not only is the use of freeway overpasses for expressive activity inconsistent *877with the purpose served by the overpasses, it takes no imagination to realize that such activity poses a grave threat to the safety and health of freeway drivers. Negotiating the freeways today is difficult enough due to the speeds reached by most drivers and the lack of skills displayed by many of them. With motorists distracted by demonstrators on the overpasses above, accidents are bound to result, some of them fatal. Thus, you could say the majority opinion is dead wrong.
This will be no small problem. As the record in this case shows, plaintiffs began using freeway overpasses because “it was a cheap and efficient economical way to get [their] message to as many people as possible.” It is inevitable that other individuals or organizations will follow suit because, as I have noted, the majority essentially invites them to protest on freeway overpasses while the authorities wait to see what effect the protests have on traffic congestion and safety.
I shudder to think of the consequences that will prevail. For example, white supremacist skinheads may be able to use the 12th Avenue overpass on Highway 99 to protest against the Dr. Martin Luther King, Jr., holiday; just think how worked up and distracted this will get drivers who are speeding down the freeways, and how unsafe this will be for those on the road. Why not dueling overpasses—Bomb Saddam advocates on the Sunrise Boulevard overpass and No War in Iraq protestors on the Mather Field Road overpass on Highway 50? The possibilities are endless. The danger to motorists is clear.
Let there be no doubt that my views on the issue are not influenced by the nature of the protest in this case. Whatever the message, allowing it to be delivered by demonstrators on a freeway overpass to traffic below presents too great a danger of physical harm to motorists.
As I will explain in detail to follow, freeway overpasses are not public forums in which to engage in expression protected by the First Amendment. Hence, the California Highway Patrol can prohibit the expression of ideas on freeway overpasses provided, as occurred in this case, that its actions are reasonable and not intended to suppress any particular point of view. If I am wrong and the law allows freeway overpasses to be used by demonstrators as public forums, then to borrow some words from Charles Dickens, “the law is a ass—a idiot.” (Dickens, Oliver Twist (1838) ch. 51 (Bumble).)
I
I begin by demonstrating why the majority’s end run around the public forum question is wrong.
*878As noted earlier, the positions of the parties in this case are relatively straightforward. Plaintiffs want to use freeway overpasses to communicate to motorists passing underneath the overpasses. Plaintiffs contend that freeway overpasses are public forums, and that they have a constitutional right to use them for communicative purposes subject only to “a reasonable time, place, manner restriction narrowly drawn to meet a significant state interest.” On past occasions, defendant California Highway Patrol (CHP) has prevented plaintiffs from using freeway overpasses to demonstrate to freeway drivers. On those occasions, plaintiffs were trying to demonstrate during periods of rush hour traffic. However, plaintiffs did not, either by pleading or by testimony, limit their request for relief to such periods.
The CHP, on the other hand, asserts that freeways and freeway overpasses are not public forums. At trial, the CHP presented clear and forceful testimony that it enforces a blanket policy of prohibiting demonstrations from freeway overpasses whenever and wherever they occur, regardless of the content of the message. The witnesses explained that such demonstrations inevitably have an adverse effect on the safe and efficient movement of freeway traffic. Thus, it is clear that, unless restrained by judicial decision, the CHP will not permit plaintiffs to demonstrate from freeway overpasses at any time.
In light of this continuing dispute, plaintiffs brought this action for (1) an injunction prohibiting the CHP “from denying plaintiffs’ constitutional right to express their views in a traditional public forum,” and (2) “[f]or a declaration by the court of the rights and duties of plaintiff[s] herein.” During preparation for trial, opposing counsel “had conversations over the last several months about trying to get as clean and clear a constitutional outcome from this proceeding as possible.” To that end, the parties endeavored to eliminate extraneous and undisputed issues by stipulation.
The parties recognize that the initial, and pivotal, issue is whether freeways and freeway overpasses are public forum properties. If so, plaintiffs’ conduct cannot be prohibited, but may be regulated by a specific and narrowly drawn time, place, and manner regulation. (Perry Ed. Assn. v. Perry Local Educators’ Assn. (1983) 460 U.S. 37, 45 [103 S.Ct. 948, 954-955, 74 L.Ed.2d 794, 804].)1 In that respect, plaintiffs asked the CHP for statutory authority relevant to such conduct. The CHP provided a list of provisions, *879including Vehicle Code sections 2410, 21465, and 21467. (Further section references are to the Vehicle Code unless otherwise specified.) Sections 21465 and 21467 were identified as the primary provisions of significance.
The majority, seizing upon the trial discussions involving statutory provisions, seeks to avoid resolving the constitutional questions presented by focusing upon statutory issues. Such an approach does not work. By adopting it, the majority fails to resolve the parties’ controversy and inevitably requires them to renew their litigative efforts.
The majority first construes sections 21465 and 21467 in a manner that excludes plaintiffs’ conduct. Having done so, the majority concludes that plaintiffs are entitled to declaratory relief stating the CHP cannot rely upon those sections to exclude plaintiffs from freeway overpasses.
The majority’s approach places the statutory cart before the constitutional horse. As the United States Supreme Court said in Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. 37 [103 S.Ct. 948, 74 L.Ed.2d 794]: “The existence of a right of access to public property and the standard by which limitations upon such a right must be evaluated differ depending on the character of the property at issue.” (Id. at p. 44 [103 S.Ct. at p. 954, 74 L.Ed.2d at p. 804].) Accordingly, the initial, and pivotal, issue that must be resolved is whether freeways and freeway overpasses are public forum properties.
In order to show cause for relief, plaintiffs must establish that they have an affirmative right to demonstrate to freeway traffic from freeway overpasses. Plaintiffs cannot establish an affirmative right simply by showing that some particular statute does not apply to them. Rather, the issue necessarily turns on whether freeways and freeway overpasses are public forums. (See Arkansas Ed. Television Comm’n v. Forbes (1998) 523 U.S. 666, 677-680 [118 S.Ct. 1633, 1641-1643, 140 L.Ed.2d 875, 886-889].) If freeways and freeway overpasses are not public forums, plaintiffs have no constitutional right to demonstrate from them and may be prohibited from doing so provided that their exclusion is not based on their viewpoint and is reasonable in light of the purposes for which the property is maintained. (Id. at p. 682 [118 S.Ct. atpp. 1643-1644, 140 L.Ed.2d at pp. 889-890].) In such case, the existence of a specific statutory exclusion is not critical. (See, e.g., Arkansas Ed. Television Comm’n v. Forbes, supra, at pp. 682-683 [118 S.Ct. at pp. 1643-1644, 140 L.Ed.2d at pp. 889-890] [exclusion based upon *880“journalistic discretion”].) If, on the other hand, freeways and freeway overpasses are public forums, plaintiffs may not be entirely prohibited from demonstrating, and may be regulated only by specific and narrowly drawn statutes or regulations. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, 74 L.Ed.2d at p. 804].) In such case, sections 21465 and 21467, which are broad, blanket prohibitions, cannot suffice. In either case, an interpretation of those sections is not determinative of the issues presented.
In any event, the majority presupposes that the removal authority granted by section 21467 is necessarily limited to the prohibitions of section 21465. However, section 21467 authorizes summary removal of “[e]very prohibited sign, signal, device, or light.” Section 21465 is not the sole source of prohibition against signs, signals, devices or lights. (See, e.g., Bus. & Prof. Code, §§ 5403, 5405.3.) A statutory provision cannot be read in isolation, but must be construed together with other laws on the same subject matter. (California Real Estate Loans, Inc. v. Wallace (1993) 18 Cal.App.4th 1575, 1582 [23 Cal.Rptr.2d 462].)
Thus, to warrant relief precluding the CHP from exercising authority under section 21467, it is not enough to conclude that section 21465 does not apply to plaintiffs conduct; rather, it must be demonstrated that plaintiffs have a right to engage in the challenged activity. In the circumstances of this case, that can be addressed only by resolving whether or not freeways and freeway overpasses are public forums.
The majority next proceeds to a discussion of section 2410 and concludes that this provision permits the CHP to prohibit plaintiffs’ activities, at least in some circumstances. Based on this conclusion, the majority further concludes that it is unnecessary to determine whether freeways and freeway overpasses are public forums. Again, the approach does not work.
First, as I have pointed out, the discussion places the statutory cart before the constitutional horse. We cannot know the standard by which to evaluate limitations upon plaintiffs’ expressive efforts until we have first determined the character of the property at issue. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 44 [103 S.Ct. at p. 954, 74 L.Ed.2d at p. 804].)
Second, the majority’s decision fails to answer numerous questions that are essential to the parties’ understanding of their rights and responsibilities. Thus, the opinion states that the CHP may prohibit plaintiffs’ demonstrations in order to ensure the free flow of traffic or to avoid traffic congestion, but *881leaves unanswered such questions as: Can section 2410 be applied as a preventative measure to avoid traffic congestion before it occurs? Since the CHP witnesses testified that expressive conduct on the freeways inevitably impedes the free flow of traffic, can the CHP exclude demonstrations in their entirety, thus effectively closing the forum if it was otherwise open? If traffic congestion is prerequisite to the application of section 2410, by what criteria is traffic congestion to be determined? Is it enough that traffic is congested or must plaintiffs’ conduct contribute to it? Whose opinion is determinative? What recourse do plaintiffs have if they disagree?
Precision is the touchstone of First Amendment jurisprudence; but the majority opinion effectively leaves the parties where they were before this litigation, without guidance to enable them to avoid future controversy, and future litigation.
Third, the majority’s approach imposes unwarranted limitations upon the issues presented by the parties. It is true that when the CHP interfered with plaintiffs’ activities in the past, plaintiffs were demonstrating during rush hours. However, plaintiffs did not suggest that they would limit their desire to demonstrate to rush hours. Rather, they plan to demonstrate from freeway overpasses “if we’ve essentially a clear legal route to do so.”
It is also true that, on prior occasions, officers were sent to the scene as the result of citizen complaints. But at trial, the officers made it clear that they did not exclude plaintiffs from the overpasses as the result of individualized consideration, but simply applied a blanket rule of exclusion. Officer Peart, who was involved in the prior incidents, testified that he would exclude demonstrators from overpasses whenever they come to his attention. Sergeant Faria, who was also involved in the prior incidents, concurred. Neither officer attempted to describe the traffic conditions at the time of the prior encounters, and neither officer tried to justify their actions by reference to particular traffic conditions.
Plaintiffs were not cited or arrested as a result of the prior incidents. They do not seek to avoid prosecution, fine, or other onus arising from those events. They do not seek recompense from the CHP based upon those events. In the trial court, evidence related to the prior events was presented solely to establish that an actual legal controversy has arisen between the parties. The legal controversy is whether plaintiffs can be prohibited entirely from demonstrating to freeway traffic from freeway overpasses. The majority’s singular focus on the prior incidents does little to resolve the actual controversy that exists.
*882Finally, by its decision the majority assumes the role of fact finder. Since the parties were interested in resolving their dispute to avoid future controversy, they did not actually litigate the question whether, in past incidents, particular circumstances existed that would warrant restriction on plaintiffs conduct, if such conduct were otherwise permissible. The trial court did not decide that question. However, if plaintiffs have a right to demonstrate from freeway overpasses subject to restriction under some circumstances, the question whether those circumstances exist is in large part factual. Since the parties did not litigate that issue, and the trial court did not decide it, this court is not in a position to determine whether, in the prior incidents, circumstances warranted application of section 2410.
The most the majority could properly conclude is plaintiffs may be prohibited from demonstrating from freeway overpasses when the circumstances described in section 2410 are present. But the negative pregnant included in such a declaration—that plaintiffs are otherwise entitled to demonstrate—is not a conclusion that we can properly reach without specifically addressing the question whether freeway overpasses are public forums.
An appellate court cannot adjudicate through the mechanism of a negative pregnant. Rather, a decision of an appellate court must be supported by a written statement of reasons. (Amwest Surety Ins. Co. v. Wilson (1995) 11 Cal.4th 1243, 1267 [48 Cal.Rptr.2d 12, 906 P.2d 1112].) And decisions “are not authority for propositions not considered.” (McDowell & Craig v. City of Santa Fe Springs (1960) 54 Cal.2d 33, 38 [4 Cal.Rptr. 176, 351 P.2d 344].) This is particularly true where the appellate court specifically declines to address an issue. (Estate of Baird (1924) 193 Cal. 225, 239 [223 P. 974]; Estate of Hall (1908) 154 Cal. 527, 531 [98 P. 269].)
Thus, while a casual reading of the majority opinion might suggest that the plaintiffs must be permitted to demonstrate from freeway overpasses at some times, such an unconsidered implication is not binding on the parties (Pacific Estates, Inc. v. Superior Court (1993) 13 Cal.App.4th 1561, 1576 [17 Cal.Rptr.2d 434]), or the trial court (People v. Shuey (1975) 13 Cal.3d 835, 841 [120 Cal.Rptr. 83, 533 P.2d 211]), and cannot serve as precedent for purposes of stare decisis (People v. Superior Court (Williams) (1992) 8 Cal.App.4th 688, 703 [10 Cal.Rptr.2d 873]).
The only appropriate conclusion that can be drawn from the majority opinion is the CHP may be able to continue to prohibit plaintiffs from demonstrating, so long as it does not purport to rely upon sections 21465 and *88321467 in doing so. If plaintiffs desire a judicial determination whether they have a right to demonstrate in at least some circumstances, they will be obliged to commence new litigation.
The majority notes the general rule, founded in the principle of judicial restraint, that we will avoid deciding constitutional questions unless doing so is strictly necessary to resolution of the case before us. The rule is well established. (Santa Clara County Local Transportation Authority v. Guardino (1995) 11 Cal.4th 220, 230-231 [45 Cal.Rptr.2d 207, 902 P.2d 225].) But it is equally well established that the rule cannot be applied rigidly where First Amendment interests are at stake and lengthy, piecemeal litigation, that may not fully vindicate those interests, must be avoided. (Baggett v. Bullitt (1964) 377 U.S. 360, 378-379 [84 S.Ct. 1316, 1326-1327, 12 L.Ed.2d 377, 389]; People v. Fogelson (1978) 21 Cal.3d 158, 163 [145 Cal.Rptr. 542, 577 P.2d 677].) Moreover, when a constitutional question is squarely presented in a justiciable controversy, it becomes our responsibility to resolve it. (See Heckler v. Mathews (1984) 465 U.S. 728, 739-740 [104 S.Ct. 1387, 1395-1396, 79 L.Ed.2d 646, 657]; Times Film Corp. v. Chicago (1961) 365 U.S. 43, 44-46 [81 S.Ct. 391, 392-393, 5 L.Ed.2d 403, 405].)
The CHP has made it clear that, unless it is advised it may not do so, it will preclude plaintiffs from demonstrating from freeway overpasses at any time and under any circumstances. A justiciable controversy has been presented by the parties that requires our determination, through a public forum analysis, whether plaintiffs have a constitutional right to demonstrate from freeway overpasses. (See California Comm’n v. United States (1958) 355 U.S. 534, 540 [78 S.Ct. 446, 450-451, 2 L.Ed.2d 470, 475].) We cannot fully and properly resolve the controversy presented without first resolving this question.
Because I have been unable to convince the majority to address the pivotal constitutional question presented in this litigation, I set forth my own views of the matter.
II
As the parties recognize, the degree to which the government can restrict a person from using public property to express the person’s views depends on the character of the property. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 44 [103 S.Ct. at p. 954, 74 L.Ed.2d at p. 804].) Therefore, they agree that the important first step in considering the issue *884tendered in this case is a “forum analysis,” although they predictably harbor differing perceptions in that regard.2
For purposes of a forum analysis, public property may be classified into three broad categories. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at pp. 45-46 [103 S.Ct. at pp. 954-956, 74 L.Ed.2d at pp. 804-805].)
The first category includes places that are quintessential public forums, i.e., “which ‘have immemorially been held in trust for the use of the public and, time out of mind, have been used for purposes of assembly, communicating thoughts between citizens, and discussing public questions.’ [Citation.]” (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, 74 L.Ed.2d at p. 804].) “In places which by long tradition or by government fiat have been devoted to assembly and debate, the rights of the State to limit expressive activity are sharply circumscribed.” (Ibid.) The government may enforce content-neutral time, place, and manner regulations that are narrowly tailored to serve a significant government interest and that leave open ample alternative channels of communication. (Ibid.) The government also may enforce a content-based exclusion if it is necessary to serve a compelling state interest and it is narrowly drawn to serve that interest. (Ibid.; accord, International Soc. for Krishna Consciousness, Inc. v. Lee (1992) 505 U.S. 672, 678 [112 S.Ct. 2701, 2705, 120 L.Ed.2d 541, 550].)
The second category of public property is that which is not a traditional public forum but which the government has opened for use by the public as a place for expressive activity. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, 74 L.Ed.2d at p. 805].) To be a public forum by “designation” (ibid.), it is not enough that *885the property be open to some forms of communication, or even that it be maintained for the purpose of communicative activity. (Id. at pp. 46-47 [103 S.Ct. at pp. 955-956, 74 L.Ed.2d at pp. 805-806]; U.S. Postal Service v. Greenburgh Civic Assns. (1981) 453 U.S. 114, 129, fn. 6 [101 S.Ct. 2676, 2685, 69 L.Ed.2d 517, 530].) Rather, it must appear that the government has intentionally opened the property for expressive activity by the general public. (Arkansas Ed. Television Comm’n v. Forbes, supra, 523 U.S. at p. 677 [118 S.Ct. at p. 1641, 140 L.Ed.2d at p. 886].) While the government is not required to retain the open character of such property indefinitely, as long as it does so it is bound by the same rules that apply to traditional public forums, i.e., “[Reasonable time, place, and manner regulations are permissible, and a content-based prohibition must be narrowly drawn to effectuate a compelling state interest.” (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 46 [103 S.Ct. at p. 955, 74 L.Ed.2d at p. 805]; accord, International Soc. for Krishna Consciousness, Inc. v. Lee, supra, 505 U.S. at p. 678 [112 S.Ct. at p. 2705, 120 L.Ed.2d at p. 550].)
The third category of public property is that which is neither by tradition nor by designation an open forum for general public communication. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 46 [103 S.Ct. at pp. 955-956, 74 L.Ed.2d at p. 805].) “[T]he First Amendment does not guarantee access to property simply because it is owned or controlled by the government.” (U.S. Postal Service v. Greenburgh Civic Assns., supra, 453 U.S. at p. 129 [101 S.Ct. at p. 2685, 69 L.Ed.2d at p. 530].) With respect to public property that is not an open forum for public communication, the government may enforce time, place, and manner regulations, and also “may reserve the forum for its intended purposes, communicative or otherwise, as long as the regulation on speech is reasonable and not an effort to suppress expression merely because public officials oppose the speaker’s view.” (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 46 [103 S.Ct. at p. 955, 74 L.Ed.2d at p. 805]; accord, International Soc. for Krishna Consciousness, Inc. v. Lee, supra, 505 U.S. at pp. 678-679 [112 S.Ct. at pp. 2705-2706, 120 L.Ed.2d at p. 550],)3
Here, the public properties at issue are freeway overpasses upon which plaintiffs desire to direct their demonstrations to freeway motorists below. In *886other words, plaintiffs seek to use public property directly over the roadway and thus within the freeway right-of-way. (Civ. Code, § 829; see Irwin v. City of Manhattan Beach (1966) 65 Cal.2d 13, 22 [51 Cal.Rptr. 881, 415 P.2d 769].)
Noting that public streets are considered to be quintessential public forums (Perry Ed. Assn. v. Perry Local. Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, 74 L.Ed.2d at p. 804]), plaintiffs argue that so too must be freeways. I disagree for reasons that follow.
“Strictly speaking, a ‘street’ is a public thoroughfare in an urban community such as a city, town, or village, and the term is not ordinarily applicable to roads and highways outside of municipalities.” (39 Am.Jur.2d (1999) Highways, Streets, and Bridges, § 8, p. 588, fn. omitted; see also Black’s Law Dict. (7th ed. 1999) p. 1435.) In other words, “[a]ll streets are highways, but not all highways are streets.” (Montgomery v. Railway Company (1894) 104 Cal. 186, 188 [37 P. 786].)
In the ordinary and conventional sense, a street is a means of intercommunication among members of the public for travel; for the conduct of personal, social, and economic intercourse; and for the convenient use of abutting properties, both commercial and residential. (See Hague v. C.I.O. (1939) 307 U.S. 496, 515-516 [59 S.Ct. 954, 963-964, 83 L.Ed. 1423, 1436-1437].) Thus, in the conventional sense, streets are built and maintained to serve the public as well as abutting property owners. (Schnider v. State of California (1952) 38 Cal.2d 439, 443 [241 P.2d 1, 43 A.L.R.2d 1068]; People ex rel. Dept. of Transportation v. Wilson (1994) 25 Cal.App.4th 977, 982 [31 Cal.Rptr.2d 52].) Members of the public traveling upon a street may stop and visit an abutting property, for business or personal purposes, and then reenter the street. (People ex rel. Dept. of Transportation v. Wilson, supra, 25 Cal.App.4th at p. 982.) And abutting property owners have a right of access to the street, which includes a right to be seen and visited by members of the public. (Schnider v. State of California, supra, 38 Cal.2d at p. 443; People ex rel. Dept. of Transportation v. Wilson, supra, 25 Cal.App.4th at p. 982.)
Traditional public forums, such as streets, “are open for expressive activity regardless of the government’s intent” because “[t]he objective characteristics of these properties require the government to accommodate public speakers.” (Arkansas Ed. Television Comm’n v. Forbes, supra, 523 U.S. at p. 678 [118 S.Ct. at p. 1641, 140 L.Ed.2d at p. 887].) In places where the general public can gather, visit, and talk, they inevitably will do so, and it *887would be impossible and wholly unreasonable for the government to attempt to prescribe expressive activity in such places. Public streets, in their ordinary and conventional sense, are precisely the type of public property that falls within the concept of a public forum.
Freeways, however, differ greatly from streets. Although streets, in their conventional sense, immemorially have been used as public forums (Hague v. C.I.O., supra, 307 U.S. at p. 515 [59 S.Ct. at pp. 963-964, 83 L.Ed. at p. 1436]), freeways are of relatively recent origin. They were created to further the development of the state with an increasingly motorized, commuter public. (See Sts. & Hy. Code, § 250.) Unlike conventional streets, freeways serve a limited and restricted purpose; they “are designed to provide rapid transit for through traffic, uninterrupted by vehicles or pedestrians from private roads and intersecting streets . . . .” (Schnider v. State of California, supra, 38 Cal.2d at p. 442.)
“It is the very essence of the idea of a freeway to prevent just [the] sort of thing [that a conventional street is maintained to serve].” (People ex rel. Dept. Public Works v. Lipari (1963) 213 Cal.App.2d 485, 491 [28 Cal.Rptr. 808].) Thus, the purpose and intent in the creation of a freeway are just the opposite of the purpose and intent in the creation and maintenance of an ordinary street or road. (People ex rel. Dept. of Transportation v. Wilson, supra, 25 Cal.App.4th at p. 982.)
In order for freeways to serve their limited purpose, they are subject to rules that are unlike those applicable to ordinary streets and roads. They are not open to the general public; rather, use is restricted to persons in motor vehicles who desire and are willing to travel in a rapid and uninterrupted manner from one place to another. (Schnider v. State of California, supra, 38 Cal.2d at p. 442.) Abutting landowners have no, or at best limited, rights of access. (Ibid.; People ex rel. Dept. of Transportation v. Wilson, supra, 25 Cal.App.4th at p. 982.) Pedestrians, bicyclists, and other relatively slow modes of transportation generally are prohibited. (§ 21960.) Motorists can enter or leave the freeway only at designated on and off ramps. (§ 21664.) They cannot stop (§ 21718) or make a turn (§ 21651). Freeways often are posted with minimum as well as maximum speed limits. (§ 22400, subd. (b).) And the Legislature has provided that no person may solicit, display, sell, offer for sale, or otherwise vend or attempt to vend any merchandise or service while being wholly or partly within the right-of-way of any freeway, including any on-ramp, off-ramp, or roadway shoulder that lies within the freeway right-of-way. (§ 22520.5, subd. (a).)
Consistent with the legislative intent of maintaining freeways for the purpose of providing uninterrupted rapid transit for through traffic, the *888Legislature has expressly delineated the types of signs or markers that California’s Department of Transportation (Caltrans) can place, maintain, or authorize along the freeway rights-of-way. The types of signs or markers within the authority of Caltrans are those reasonably necessary or convenient for purposes of rapid transit. For example, Caltrans can maintain certain directional signs. (Sts. & Hy. Code, § 100.9 [directions to a city or business district]; Sts. & Hy. Code, §§ 101, 123.5 [historical sites]; Sts. & Hy. Code, § 131.5 [governmental maintained roadside rest areas]; § 21375 [institutions of postsecondary education].) In rural areas, it can maintain signs advising motorists of the fuel, food, lodging, or camping services that can be obtained at the next exit (Sts. & Hy. Code, § 101.7), or of the location of a fire station (Sts. & Hy. Code, § 101.9). And, of course, it can place, maintain, or cause to be placed or maintained appropriate and necessary signs, signals, and other traffic control devices. (§ 21350.) Other than the signs or markers the Legislature has specifically authorized, Caltrans has been given no general authority to place, maintain, or approve communicative activities within the freeway rights-of-way.4
It is these attributes that distinguish freeways from the type of ordinary or conventional streets which traditionally have been used as public forums. These attributes also make it impossible for a freeway to serve the usual purposes for which public forums exist, such as assembly, public discussion and debate, and the communication of thoughts among members of the public. (Hague v. C.I.O., supra, 307 U.S. at p. 515 [59 S.Ct. at pp. 963-964, 83 L.Ed. at p. 1436].) There simply cannot be free and open assembly, public debate, or an exchange of ideas in a location where pedestrians are forbidden, motorists cannot stop, and traffic passes at relatively high speeds.
The United States Supreme Court “has rejected the view that traditional public forum status extends beyond its historic confines . •. . .” (Arkansas Ed. Television Comm’n v. Forbes, supra, 523 U.S. at p. 678 [118 S.Ct. at p. 1641, 140 L.Ed.2d at p. 887].) Rather, the development of new methods of transportation requires the development of new methods of accommodating that transportation, and each new step requires a new inquiry into the compatibility of transportation necessities and various kinds of expressive *889activity. (International Soc. for Krishna Consciousness, Inc. v. Lee, supra, 505 U.S. at p. 681 [112 S.Ct. at pp. 2706-2707, 120 L.Ed.2d at p. 552].) While I understand plaintiffs’ desire to direct their communication to freeway motorists (freeways provide an essentially captive audience with a relatively high volume of viewers), the efficiency of the medium does not dictate that the property be treated as a public forum. (U.S. Postal Service v. Greenburgh Civic Assns., supra, 453 U.S. at p. 129 [101 S.Ct. at p. 2685, 69 L.Ed.2d at pp. 529-530].)
Accordingly, I am compelled to conclude that freeways, which serve a limited purpose wholly opposite that of ordinary streets, are not public forums. In reaching this conclusion, I am mindful of the United States Supreme Court’s decision in Frisby v. Schultz (1988) 487 U.S. 474 [108 S.Ct. 2495, 101 L.Ed.2d 420], which addressed a city’s adoption of an ordinance that completely banned picketing before or about any residence. The city asserted that its streets should not be considered public forums due to their physical narrowness and residential character. (Id. at p. 480 [108 S.Ct. at p. 2500, 101 L.Ed.2d at p. 429].) The Supreme Court disagreed: “No particularized inquiry into the precise nature of a specific street is necessary; all public streets are held in the public trust and are properly considered traditional public fora.” (Id. at p. 481 [108 S.Ct. at p. 2500, 101 L.Ed.2d at p. 429].)5 However, Frisby v. Schultz would compel a conclusion favorable to plaintiffs’ position only if this court were to extend the holding beyond the usual and ordinary meaning of “street” and find its reasoning applicable to any government property dedicated to some form of travel, regardless how limited or restricted. We are not at liberty to do so, as I will explain.
“First Amendment rights must always be applied ‘in light of the special characteristics of the . . . environment’ in the particular case. [Citation.]” (Healy v. James (1972) 408 U.S. 169, 180 [92 S.Ct. 2338, 2345, 33 L.Ed.2d 266, 279].) It is not travel per se that makes a street a public forum; rather, it is the street’s inherent capacity and traditional use for purposes of assembly, discussion, and other forms of social, economic, and political intercourse. (Compare Hague v. C.I.O., supra, 307 U.S. at p. 515 [59 S.Ct. at pp. 963-964, 83 L.Ed. at p. 1436], with International Soc. for Krishna Consciousness, Inc. v. Lee, supra, 505 U.S. at p. 681 [112 S.Ct. at pp. 2706-2707, 120 L.Ed.2d at p. 552].)
Freeways, unlike ordinary streets, are ill-suited to serve those purposes of public forums and, in their relatively brief history, freeways have not been held open for such purposes.
*890In this respect, I find the decision in Greer v. Spock (1976) 424 U.S. 828 [96 S.Ct. 1211, 47 L.Ed.2d 505] to be significant. It involved the Fort Dix Military Reservation, which contained roads and footpaths open to civilian use. Civilians were permitted to visit any unrestricted area of the reservation, but expressive activities, such as demonstrations, picketing, marches, and political speeches, were prohibited. (Id. at pp. 830-831 [96 S.Ct. at pp. 1213-1214, 47 L.Ed.2d at pp. 509-510].) In rejecting a First Amendment challenge to the prohibition upon expressive activities, the Supreme Court distinguished the roads and footpaths on the military reservation from “a municipality’s open streets, sidewalks, and parks” and concluded the open roads and footpaths on the military reservation were not public forums. (Id. at pp. 835, 838 [96 S.Ct. at p. 1216, 1217-1218, 47 L.Ed.2d at pp. 512-513, 514].) In reaching this conclusion, the court noted that the business of a military reservation is “to train soldiers, not to provide a public forum.” (Id. at p. 838 [96 S.Ct. at p. 1217, 47 L.Ed.2d at p. 514].)
The decision in Greer v. Spock, supra, 424 U.S. 828 [96 S.Ct. 1211, 47 L.Ed.2d 505] demonstrates that when the United States Supreme Court speaks of streets as traditional public forums, it uses the word “street” in the ordinary and conventional sense, i.e., in reference to the public streets of a municipality. The court does not necessarily extend the meaning of “street,” and hence the status of public forum, to every pathway of travel in the public domain. This is consistent with the court’s statement that while a public forum analysis generally provides a workable analytical tool, the distinctions may blur at the edges, particularly “in cases falling between the paradigms of government property interests essentially mirroring analogous private interests and those clearly held in trust, either by tradition or recent convention, for the use of citizens at large.” (City Council v. Taxpayers for Vincent (1984) 466 U.S. 789, 815, fn. 32 [104 S.Ct. 2118, 2134, 80 L.Ed.2d 772, 794].) It also is consistent with the court’s view that First Amendment rights must always be applied in light of the environment in the particular case. (Healy v. James, supra, 408 U.S. at p. 180 [92 S.Ct. at pp. 2345-2346, 33 L.Ed.2d at p. 279].)
Freeways are not streets in the ordinary and conventional use of the word “street” and, with their limited purpose and restricted use, freeways have not been held in trust for the general use of the public at large.6
Because freeways and government property within a freeway right-of-way, such as freeway overpasses, are not public forums, the government *891may reserve them for their “intended purposes” as long as the restriction on speech is reasonable and not an effort to suppress views with which public officials disagree. (Perry Ed. Assn. v. Perry Local Educators ’ Assn., supra, 460 U.S. at p. 46 [103 S.Ct. at pp. 955-956, 74 L.Ed.2d at p. 805].)
At trial, the CHP relied upon two bases for prohibiting expressive activity on freeway overpasses—efficiency and safety. I find these bases to be reasonable.
Evidence in the record shows that plaintiffs purposely timed their demonstrations for periods of heaviest freeway use, so-called rush hours. While plaintiffs did so in order to reach the greatest number of drivers, those also are times that involve the greatest potential for disruption of the efficient flow of traffic and the greatest danger to motorists from driver distraction.
The CHP presented testimony that any form of visual distraction on the freeways impedes the smooth flow of traffic, particularly during periods of high use or congestion. Accordingly, during commute times, the CHP employs a tow truck service to remove stalled vehicles as soon as possible; and officers even avoid making enforcement stops to prevent deleterious effects on traffic flow. Likewise, it is obvious that the efficient movement of traffic would be adversely affected by expressive demonstrations aimed at freeway drivers.
The governmental concern for efficiency is well founded. Our increasingly congested freeways have caused the Legislature to take steps to promote efficiency, including, among other things, the placement of call boxes to enable motorists in need of aid to obtain assistance (Sts. & Hy. Code, § 2550), and the permanent implementation of a freeway service patrol system on traffic-congested urban freeways. (Sts. & Hy. Code, § 2560 et seq.) Distractions that can inhibit the smooth flow of traffic are matters of legitimate governmental concern since such distractions can hamper the ability of freeways to serve the purpose for which they are built and maintained.
Even more important is the adverse effect on public safety that expressive demonstrations would entail. In the high-speed, high-volume flow of traffic on a freeway, it is particularly important that drivers pay attention to driving. The specific purpose of an expressive demonstration aimed at freeway *892motorists is to gain their attention to a message, and thus distract them from their driving. In the high-speed, high-volume traffic flow of a freeway, a distracted driver is a significant safety hazard.
It cannot be denied that traffic safety is a legitimate governmental concern. In upholding a ban on advertising on vehicles using the streets of New York City, the United States Supreme Court said that it was within the discretion of the city to conclude that such advertising “constitutes a distraction to vehicle drivers and to pedestrians alike and therefore affects the safety of the public in the use of the streets.” (Railway Express v. New York (1948) 336 U.S. 106, 109 [69 S.Ct. 463, 465, 93 L.Ed. 533, 538].) And in upholding a local ordinance declaring to be a nuisance any advertising sign adjacent to a freeway and designed to be viewed by freeway travelers, the California Supreme Court said the ordinance served “the obvious purposes of promoting highway safety as well as enhancing community aesthetic values.” (City of Escondido v. Desert Outdoor Advertising, Inc. (1973) 8 Cal.3d 785, 790 [106 Cal.Rptr. 172, 505 P.2d 1012], disapproved on another point in San Diego Bldg. Contractors Assn. v. City Council (1974) 13 Cal.3d 205, 216 [118 Cal.Rptr. 146, 529 P.2d 570, 72 A.L.R.3d 973].)
Testimony introduced by the CHP established that its ban on expressive activity on freeways is applied in an across-the-board manner without regard to content. There is no basis in the record to dispute that the prohibition in this case was not an attempt to suppress any particular point of view. I am aware of anecdotal information, outside the record of this appeal, that action has not been taken in some areas to remove patriotic symbols and messages posted on freeway overpasses following the despicable terrorist attacks on September 11, 2001. However, there is no evidentiary basis iii this case to conclude that the CHP’s action against plaintiffs was taken to suppress their particular point of view or that the CHP employs its ban on expressive activity on freeways in a manner so as to suppress any particular points of view.
Because the governmental interests of efficiency and traffic safety are reasonable grounds for excluding expressive activities from freeway rights-of-way, and there is no basis in the record of this case to establish that the CHP employs its policy in a manner to suppress particular points of view, plaintiffs can be prevented from demonstrating on freeway overpasses.
Ill
Plaintiffs nevertheless suggest that they must be permitted to demonstrate to freeway traffic from freeway overpasses because, in doing so, they are not required to stand on the surface of the freeway itself. The argument fails.
*893Civil Code section 829 provides: “The owner of land in fee has the right to the surface and to everything permanently situated beneath or above it.” This is consistent with Civil Code section 659, which states: “Land is the material of the earth, whatever may be the ingredients of which it is composed, whether soil, rock, or other substance, and includes free or occupied space for an indefinite distance upwards as well as downwards, subject to limitations upon the use of airspace imposed, and rights in the use of airspace granted, by law.”
Specific to state highways, Streets and Highway Code section 660 provides: “(a) [The term] ‘[h]ighway’ includes all, or any part, of the entire width of the right-of-way of a state highway, whether or not the entire area is actually used for highway purposes, [f] (b) [The term] 1 [e]ncroachment’ includes any tower, pole, pole line, pipe, pipe line, fence, billboard, stand or building, or any structure, object of any kind or character not particularly mentioned in this section, or special event, which is [placed] in, under, or over any portion of the highway.”
These statutes reflect the general rule that a property owner has the right to the enjoyment and control of the airspace above the property that is reasonably adaptable to the beneficial use of the. property. (Strother v. Pacific Gas & Elec. Co. (1949) 94 Cal.App.2d 525, 537 [211 P.2d 624].) This rule was a fundamental premise of the litigation in Irwin v. City of Manhattan Beach, supra, 65 Cal.2d 13, a decision that held a municipality could properly authorize the construction of a pedestrian walkway over a city street, and “could limit the use of the structure in any reasonable manner, including its withdrawal from the access of the public at large.” (Id. at p. 22.)
Freeway overpasses serve the dual interests of the state and of the surrounding community. Overpasses serve the interest of the state by enabling it to maintain freeways as a means of rapid, uninterrupted transit for through traffic. (Schnider v. State of California, supra, 38 Cal.2d at p. 442.) And they serve the interest of the surrounding community by preventing the schism that would occur if access from one part of the community to another were severed by the freeway. (See Sts. & Hy. Code, §§ 100.2, 941.2, 1801.)
The exercise of control over streets and roads is an exercise of the sovereign power of the state. (Exparte Daniels (1920) 183 Cal. 636, 639-641 [192 P. 442, 21 A.L.R. 1172].) Any right of control that is not expressly delegated to local government is retained by the state, and any grant of authority is strictly construed in favor of state control. (Ibid.; Rumford v. City of Berkeley (1982) 31 Cal.3d 545, 549-550 [183 Cal.Rptr. 73, 645 P.2d *894124].) While local governments may be permitted to exercise some control over freeway overpasses as part of their local road system, the state retains control over those overpasses at least to the extent necessary or appropriate for the operation and use of the freeway for its intended purposes.
• Accordingly, plaintiffs are not free of state control simply because they conduct their activities from freeway overpasses within the freeway right-of-way rather than upon the surface of the freeway itself.
“[F]orum analysis is not completed merely by identifying the government property at issue. Rather, in defining the forum [courts] have focused on the access sought by the speaker.” (Cornelius v. NAACP Legal Defense & Ed. Fund (1985) 473 U.S. 788, 801 [105 S.Ct. 3439, 3448, 87 L.Ed.2d 567, 579].) This entails consideration of the audience the speaker wishes to reach as well as the physical property from which the speaker wishes to act. (Ibid.)
Freeway overpasses are within the freeway rights-of-way, and by principles of general law, as well as by provisions of the Streets and Highway Code, they are under the control of the state for freeway purposes. Plaintiffs demand to use the overpasses for the sole and specific purpose of demonstrating to freeway traffic. The CHP excluded plaintiffs from the overpasses for the sole purpose of preventing them from demonstrating to freeway traffic. Consideration of both the nature of the property and the access sought by plaintiffs compels the conclusion that, in this respect, freeway overpasses, like freeways themselves, are not public forums.
IV
Plaintiffs claim that the exclusion of their demonstrations from freeway overpasses has the effect of treating political speech less favorably than commercial speech, which is inconsistent with First Amendment values. (See Metromedia, Inc. v. San Diego (1981) 453 U.S. 490, 513 [101 S.Ct. 2882, 2895, 69 L.Ed.2d 800, 818]; Metromedia, Inc. v. City of San Diego (1982) 32 Cal.3d 180, 184 [185 Cal.Rptr. 260, 649 P.2d 902].) The contention is not persuasive.
In support of this assertion', plaintiffs point to provisions of the Outdoor Advertising Act (Bus. & Prof. Code, § 5200 et seq.), which permits off-site *895advertising on private property, generally referred to as billboard advertising.7 However, a private citizen’s interest in controlling the use of his or her own property justifies different treatment from other types of expressive activity. (See City Council v. Taxpayers for Vincent, supra, 466 U.S. 789, 811 [104 S.Ct. 2118, 2132, 80 L.Ed.2d 772, 791].) Hence, the activity regulated by the act is not comparable to plaintiffs’ activity, and need not be treated the same. In any event, the act flatly prohibits the placement or maintenance of any advertising display “within the right-of-way of any highway.” (Bus. & Prof. Code, § 5403, subd. (a).)
Plaintiffs also point to on-site advertising, such as signs on commercial buildings adjacent to a freeway, which are not covered by the Outdoor Advertising Act (Bus. & Prof. Code, § 5272, subd. (d)) and which, plaintiffs claim, are unregulated. In fact, on-site advertising is subject to regulation by local government through ordinance. (Gov. Code, § 65850, subd. (b); Bus. & Prof. Code, § 5443, subd. (a).) But what is significant is that on-site advertising involves a property owner’s interest in controlling the use of his or her property and, by definition, cannot be conducted within a freeway right-of-way. Hence, it is not comparable to the activity in which plaintiffs wish to engage.
As another example of commercial speech that is permitted along freeways, plaintiffs note that Caltrans places signs within freeway rights-of-way, advising motorists of traveler’s amenities, such as gas, food, or lodging, that can be obtained by leaving the freeway at a particular offramp. At times, these signs include the name or logo of the particular purveyor of the goods or services available. These signs, like directional signs in general, convey information of importance to the traveling public and serve the intended purposes of a freeway. Where public property is not a public forum, government can permit communicative activity consistent with the property’s intended purpose without opening the property to expressive activity in general. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at pp. 46-47 [103 S.Ct. at pp. 955-956, 74 L.Ed.2d at pp. 805-806].)
Plaintiffs also complain that their communication has been banned whereas some forms of otherwise unauthorized communication, such as commercial signs on the sides of city buses and bumper stickers on vehicles, are not excluded from the freeways. However, a lawful distinction may be *896drawn between (1) a motorist using the freeway for its intended purpose, consistent with the rules of the road demanded therein, who incidentally has a message attached to his or her vehicle, and (2) a person who does not wish to use the freeway for its intended purpose at all. (Railway Express v. New York, supra, 336 U.S. at pp. 109-110 [69 S.Ct. at pp. 465-466, 93 L.Ed. at p. 538-539]; see also Lehman v. City of Shaker Heights (1974) 418 U.S. 298, 301-302 [94 S.Ct. 2714, 2716-2717, 41 L.Ed.2d 770, 776-777].) The fact that some forms of incidental communication are not excluded from the freeways does not have the effect of opening the freeways to all forms of communication whether or not related to the intended purpose of those properties.
In the final analysis, it must be kept in mind that freeway rights-of-way are not public forums. In dealing with public property that is not a public forum, the state can exclude some types of expressive activity even though other types are permitted. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at pp. 46-49 [103 S.Ct. at pp. 955-957, 74 L.Ed.2d at pp. 805-807].) Unless, by policy or practice, the state has opened the property to the indiscriminate use of the general public for expressive purposes, the relevant question is not whether some forms of expression are permitted, but is whether the exclusion of the particular activity at issue is reasonable. (Ibid.; see United States v. Kokinda (1990) 497 U.S. 720, 733-734 [110 S.Ct. 3115, 3123-3124, 111 L.Ed.2d 571, 586].) In this respect, courts focus on the excluded activity and must recognize that the state is entitled to address activities it believes particularly warrant control without being required to address other, lesser evils. (United States v. Kokinda, supra, 497 U.S. at pp. 733-734 [110 S.Ct. at pp. 3123-3124, 111 L.Ed.2d at p. 586]; Railway Express v. New York, supra, 336 U.S. at p. 110 [69 S.Ct. at pp. 465-466, 93 L.Ed. at pp. 538-539].)
For reasons I already have explained, excluding demonstrations from freeway rights-of-way is reasonable.
V
As noted previously, the primary statutory authorities that the CHP witnesses cited at trial were sections 21465 and 21467. Section 21465 provides: “No person shall place, maintain, or display upon, or in view of, any highway any unofficial sign, signal, device, or marking, or any sign, signal, device, or marking which purports to be or is an imitation of, or resembles, an official traffic control device or which attempts to direct the movement of traffic or which hides from view any official traffic control device.” An *897“unofficial sign, signal, device, or marking” within the meaning of this section is one that is not placed, caused to be placed, or authorized by the Department of Transportation. (§§ 440, 445, 21350, 21400; Sts. & Hy. Code, §§ 230, 250.) Section 21467 authorizes the CHP to remove, or cause to be removed, every “prohibited sign . . . .”
Plaintiffs argue these sections do not provide authority for the CHP’s enforcement action against them because, in plaintiffs’ view, section 21465 does not, by its terms, apply to any signs other than those that purport to regulate traffic control or that block traffic control devices. They raise the specter that, if construed otherwise, section 21465 would permit the CHP to prohibit plaintiffs from displaying their signs and banners “in a manner viewable from any street.” In essence, plaintiffs contend that, unless their construction of section 21465 is adopted, the statute is overbroad and therefore unconstitutional. This issue need not be addressed for the following reasons.
At trial, it was established that the CHP has not interfered with plaintiffs’ expressive activities in any location other than on freeway overpasses. Plaintiffs brought this litigation for the specific and limited purpose of obtaining injunctive and declaratory relief that would compel the CHP to permit them to demonstrate on freeway overpasses. Their specific claim is that freeway overpasses are traditional public forums and, thus, their demonstrations cannot be precluded by the CHP. As the litigation has progressed, plaintiffs have begun to focus on sections 21465 and 21467. They appear to believe that if those sections are construed so as not to include their conduct, or are declared unconstitutional, plaintiffs will be entitled to the relief they seek.
Plaintiffs’ argument presupposes that specific statutory authority is a prerequisite to the exclusion of demonstrations from within the freeway rights-of-way. It is not.
In addressing this issue, we must keep in mind that freeway rights-of-way, and freeway overpasses, are not public forums. Where a public forum is involved, a narrowly drawn statute or regulation is essential to exclude or limit expression. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, 74 L.Ed.2d at p. 804].) But the United States Supreme Court has not held that a statute or regulation is essential for the exclusion of expressive activity from property that is not a public forum. To the contrary, in non-public forum cases, the court has upheld exclusions that were not based on statute or regulation.
*898In Lehman v. City of Shaker Heights, supra, 418 U.S. 298 [94 S.Ct. 2714, 41 L.Ed.2d 770], the city operated a rapid transit system and sold advertising space for “car cards” on its vehicles. The city hired an agent to manage advertising space on its transit system. The contract provided that political advertising would not be allowed. (Id. at pp. 299-300 [94 S.Ct. at pp. 2715-2716, 41 L.Ed.2d at p. 775].) No statute, ordinance, or regulation was involved; there simply was a city policy reflected in the contract with its agent. Nevertheless, after concluding the city’s transit system was not a public forum, the court upheld the exclusion as reasonable. (Id. at p. 304 [94 S.Ct. at pp. 2717-2718, 41 L.Ed.2d at p. 778].)8
In Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. 37 [103 S.Ct. 948, 74 L.Ed.2d 794], a school district entered into a collective bargaining agreement that gave the teachers’ union access to the district’s interschool mail system and teacher mailboxes while denying such access to any other school employee organization. (Id. at p. 40 [103 S.Ct. at p. 952, 74 L.Ed.2d at p. 801].) No statute, ordinance, or regulation was at issue; there simply was a policy decision that was reflected in the collective bargaining agreement. After concluding that the internal mail system and teacher mailboxes were not public forums, the court upheld the exclusion as reasonable. (Id. at pp. 48-52 [103 S.Ct. at pp. 956-959, 74 L.Ed.2d at pp. 807-809].)
In Arkansas Ed. Television Comm’n v. Forbes, supra, 523 U.S. 666 [118 S.Ct. 1633, 140 L.Ed.2d 875], a state-owned public television station sponsored a debate between major party candidates for Congress, and excluded an independent candidate with little popular support. (Id. at p. 670 [118 S.Ct. at pp. 1637-1638, 140 L.Ed.2d at p. 882].) The exclusion was not pursuant to .a specific statute, ordinance, or regulation; it simply was an exercise of discretion by station officials. (Ibid.) The court concluded that the debate was not a public forum (id. at p. 680 [118 S.Ct. at pp. 1642-1643, 140 L.Ed.2d at p. 889]) and upheld the exclusion as “a reasonable, viewpoint-neutral exercise of journalistic discretion consistent with the First Amendment.” (Id. at p. 683 [118 S.Ct. at p. 1644, 140 L.Ed.2d at p. 890].)
In Hazelwood School District v. Kuhlmeier (1988) 484 U.S. 260 [108 S.Ct. 562, 98 L.Ed.2d 592], a school principal excluded two articles from a student newspaper. The exclusion was not based on a specific statute or regulation, but was simply an exercise of educational discretion. (Id. at *899pp. 263-264 [108 S.Ct. at pp. 565-566, 98 L.Ed.2d at p. 600].) Finding the newspaper was not a public forum (id. at p. 270 [108 S.Ct. at pp. 567-570, 98 L.Ed.2d at pp. 604-605]), the court upheld the exclusion because the principal’s action was reasonable under the circumstances as he knew them. (Id. at p. 276 [108 S.Ct. at pp. 572-573, 98 L.Ed.2d at p. 608].)
As these decisions demonstrate, when property is not a public forum, the exclusion of expressive activity need not be based upon a specific, narrowly drawn statute or regulation. An exclusion can be based upon such things as a policy decision or the exercise of official discretion.
Accordingly, the CHP’s authority to prohibit plaintiffs from demonstrating on freeway overpasses is not necessarily dependent upon the interpretation and constitutional validity of sections 21465 and 21467.
In establishing a freeway system, the Legislature took steps to ensure that the public use of freeways would be limited to the intended purpose of freeways. Thus, as I have noted, access is limited and controlled. (§ 21664; Schnider v. State of California, supra, 38 Cal.2d at p. 442; People ex rel. Dept. of Transportation v. Wilson, supra, 25 Cal.App.4th at p. 982.) Pedestrians, bicyclists, and other slow modes of transportation generally are prohibited. (§21960.) Motorists cannot stop (§21718) or make a turn (§ 21651). There are often minimum as well as maximum speed limits on freeways. (§ 22400, subd. (b).) And the Legislature has excluded commercial activity from the freeway rights-of-way. (§ 22520.5, subd. (a).)
The Legislature has expressly delineated the types of signs and markers that can be placed or maintained within the freeway rights-of-way. (See, e.g., §21375; Sts. & Hy. Code, §§ 100.9, 101, 101.1, 101.6, 101.7, 101.8, 101.9, 123.5, 131.5.) As part of the Outdoor Advertising Act, the Legislature expressly precluded any advertising sign from being placed or maintained within the freeway rights-of-way. (Bus. & Prof. Code, § 5403, subd. (a).) Although Caltrans has full possession and control of the freeways (Sts. & Hy. Code, § 90), it has been given no statutory authority to place, maintain, or authorize any sign or marker other than those delineated by the Legislature. Neither Caltrans nor the CHP has been given statutory authority to authorize or permit the freeway rights-of-way to be used for expressive purposes, like protests or demonstrations.
The CHP is the law enforcement agency with full responsibility and primary jurisdiction for the administration and enforcement of the laws on freeways. (§ 2400, subd. (d).) The CHP’s duties include the enforcement of all laws regulating the operation of vehicles and the use of the freeways. *900(§ 2400, subd. (b).) It is required to “perform all duties, exercise all powers and jurisdiction, assume and discharge all responsibilities, and carry out and effect all purposes vested by law in the department.” (§ 2108.) This includes providing adequate patrol of the freeways at all times of the day and night. (§ 2401.) “Members of the [CHP] are authorized to direct traffic according to law, and, in the event of a fire , or other emergency, or to expedite traffic or insure safety, may direct traffic as conditions may require notwithstanding the provisions of this code.” (§ 2410.) Traffic includes pedestrians. (§ 620.)
These statutory provisions make it clear that the CHP has the responsibility to patrol the freeways and to take action to ensure the safe and efficient movement of traffic thereon. In performing this duty, a CHP officer may give any order, signal, or direction that is relevant and reasonably necessary to the accomplishment of that purpose. (People v. Ritter (1980) 115 Cal.App.3d Supp. 1, 6 [170 Cal.Rptr. 901].) And it is unlawful for any person to willfully fail or refuse to comply with any lawful order, signal, or direction by a CHP officer. (§ 2800.)
Having considered the totality of the circumstances and the law applicable to this case, I conclude that, without relying on sections 21465 and 21467, the CHP can prevent plaintiffs from demonstrating to freeway traffic from freeway overpasses. I reach this conclusion for the following reasons: (1) freeways and freeway overpasses are not public forums, and plaintiffs have no right to demonstrate to freeway traffic from within the freeway rights-of-way; (2) the Legislature consistently has acted to exclude from the freeway rights-of-way all objects and activities that are not related to the purpose of providing a means of uninterrupted rapid transit for through traffic; (3) the Legislature has not authorized Caltrans or the CHP to permit unrelated expressive activities within freeway rights-of-way; (4) the CHP has broad responsibility over the freeways, and its duties include taking action to promote the safe and efficient flow of traffic on the freeways; (5) it was established at trial, and it is a matter of common sense, that demonstrations directed at freeway traffic from within the freeway rights-of-way can have a serious deleterious effect on both traffic safety and efficiency; and (6) in the performance of their duties, CHP officers may issue orders, signals, and directions relevant and reasonably necessary to the accomplishment of their responsibilities.
It follows that the CHP has authority to preclude plaintiffs from demonstrating to freeway traffic from freeway overpasses, regardless of any determination that we might reach with respect to the interpretation and constitutional validity of sections 21465 and 21467.
*901VI
Although, in my view, sections 21465 and 21467 are not determinative of the issues presented, I pause here briefly to note my disagreement with the majority’s interpretation of those statutes.
Section 21465 provides: “No person shall place, maintain, or display upon, or in view of, any highway any unofficial sign, signal, device, or marking, or any sign, signal, device, or marking which purports to be or is an imitation of, or resembles, an official traffic control device or which attempts to direct the movement of traffic or which hides from view any official traffic control device.”
In the statute, the Legislature used the words “sign, signal, device, or marking” twice, separated by the disjunctive “or.” The first iteration is preceded by the qualifier “unofficial”; while the second refers to those that are related to traffic control devices. From the repetition of the words, with the “unofficial” qualifier limited to the first usage, it appears that the Legislature understood unofficial signs to refer to signs other than those related to traffic control devices.
The majority’s interpretation of section 21465 limits its reach to signs related to traffic control devices, thus rendering the words “unofficial sign, signal, device, or marking” surplusage. But what has been called a cardinal rule of statutory construction dictates that courts must avoid an interpretation that would make some of the statutory words surplusage. (Moyer v. Workmen’s Comp. Appeals Bd. (1973) 10 Cal.3d222, 230 [110 Cal.Rptr. 144, 514 P.2d 1224]; People v. Gilbert (1969) 1 Cal.3d 475, 480 [82 Cal.Rptr. 724, 462 P.2d 580].) In construing the statute, we must, if it is possible, give effect to the words “unofficial sign, signal, device, or marking.”
A statute should not be read in isolation; rather, it must be construed together with other statutes on the same subject. (California Real Estate Loans, Inc. v. Wallace, supra, 18 Cal.App.4th at p. 1582.) With respect to freeways, which are the properties at issue here, there is statutory guidance as to what constitutes an unofficial sign, signal, device, or marking.
Under the Legislature’s scheme for freeways, the Legislature by statute directs or authorizes Caltrans to place or maintain certain types of signs within the freeway rights-of-way. (§ 21350.) While Caltrans is concerned *902with traffic control signs and devices, that is not exclusive. The department’s authority extends to signs, signals, and markings “as may be necessary properly to indicate and to carry out the provisions of this code, or to warn or guide traffic upon the highways.” (§ 21350.) Specific signs or markings that may be maintained or authorized by Caltrans include markings to direct visitors and tourists to points of local interest (§ 21374), signs indicating the off-ramp which may be used to reach postsecondary educational institutions (§ 21375), informational signs concerning rail transportation services and fire station access (Sts. & Hy. Code, §§ 101.8, 101.9), and informational signs concerning the availability of fuel, food, lodging or camping (Sts. & Hy. Code, § 101.7). Caltrans is not given the power to place or maintain, or authorize to be placed or maintained, signs that are not related to the purposes of freeways for travel and that are not statutorily authorized.
The word “official” denotes something that is done under color or by virtue of a public office rather than privately. (People v. Norris (1985) 40 Cal.3d 51, 55 [219 Cal.Rptr. 7, 706 P.2d 1141].) It follows that “unofficial” refers to things or actions that are private and, are not under color or by virtue of a public office. Accordingly, in light of the legislative scheme for freeways, it appears that an unofficial sign, signal, device, or marking is one which is not authorized by the Legislature or placed or authorized by Caltrans in the exercise of its administrative authority over freeways. (§ 21350, Sts. & Hy. Code, §§ 230, 250.) To conclude otherwise would render Caltrans’s authority illusory, since there would be no requirement of the department’s approval for the private placement or display of signs, signals, devices, or markings that are not related to traffic control devices.
In any event, as I have previously noted, the removal authority conferred by section 21467 is not necessarily limited to the prohibitions of section 21465. Hence, a narrow construction of section 21465 does not in itself establish a right in the plaintiffs to display signs from within the freeway rights-of-way.
During appellate proceedings, plaintiffs have suggested that, because section 21465 is not limited to freeways, an interpretation of its provisions that would include plaintiffs’ conduct would be unconstitutionally overbroad because the statutes would prohibit demonstrators from engaging in the protected activity of displaying the signs in the view of streets that are traditional public forums. This court asked the parties, through supplemental briefing, to address the question whether section 21465 is overbroad and, if so, whether the overbreadth can be cured through judicial decision. Since *903neither my view nor the majority’s view of the controversy requires us to consider such questions, I will not venture an opinion on them. I simply note that, in the trial court, plaintiffs did not raise the overbreadth issue, nor did they specifically challenge the constitutionality of section 21465. And plaintiffs did not allege, or attempt to prove, that they have, or anyone else has, been prohibited or deterred from engaging in expressive activity anywhere other than on freeway overpasses. In fact, the evidence showed that plaintiffs have conducted their demonstrations without interference on streets and highways within Sacramento, and were restricted only with respect to freeway overpasses. Besides, there is no “realistic danger that [section 21465] will significantly compromise recognized First Amendment protections of [plaintiffs or] parties not before the Court for it to be facially challenged on overbreadth grounds.” (City Council v. Taxpayers for Vincent, supra, 466 U.S. at p. 801 [104 S.Ct. at p. 2126, 80 L.Ed.2d at p. 784].) The development of the law applicable to public forums and the unequivocal judicial precedents establishing an ordinary and conventional street as a public forum make it decidedly unlikely that any agency or local jurisdiction would attempt to apply section 21465 to prohibit expressive activity in such a traditional public forum.
Summary
Freeways and freeway overpasses within the freeway rights-of-way are not public forums. Plaintiffs have no constitutionally protected right to demonstrate to freeway traffic from a location within the freeway rights-of-way. The CHP has the authority to preclude them from doing so. The exclusion of demonstrations from within the freeway rights-of-way promotes the safe and efficient use of freeways for their intended purpose and is reasonable. The evidence in this case established that the CHP applies the policy in a content-neutral, across-the-board manner, and nothing in the record suggests that the CHP was attempting to suppress a particular point of view.
In reaching these conclusions, I limited my consideration to the record before us. If it were shown that, by policy or by practice, the state had opened the freeway rights-of-way to indiscriminate use by the general public, this would be a different case. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 47 [103 S.Ct. at p. 956, 74 L.Ed.2d at p. 806].) If it were shown that the CHP engaged in selective enforcement in an effort to suppress particular points of view, this would be a different case. (Id. at p. 46 [103 S.Ct. at pp. 955-956, 74 L.Ed.2d at p. 805].) But nothing in the record before this court would support such findings.
*904Accordingly, I agree with the trial court that the CHP may properly preclude plaintiffs from demonstrating to freeway traffic from freeway overpasses. Thus, I would affirm the judgment in its totality.
In addition to enforcing time, place, and manner regulations, the government can entirely exclude a particular speaker from a public forum if the exclusion is necessary to serve a compelling government interest and the exclusion is narrowly drawn to serve that end. (Perry Ed. Assn. v. Perry Local Educators’ Assn., supra, 460 U.S. at p. 45 [103 S.Ct. at pp. 954-955, *87974 L.Ed.2d at p. 804].) However, no one in this litigation has suggested that any content-based distinction may be applied to plaintiffs.
Plaintiffs claim the First Amendment of the United States Constitution and article I, section 2 of our state Constitution preclude interference with their demonstrations. However, plaintiffs offer no argument or analysis as to why a forum analysis under the California Constitution should be applied differently than is such an analysis under the First Amendment. In fact, except for several brief and conclusory references to our state Constitution, plaintiffs’ entire argument is predicated on a First Amendment analysis. Thus, they end their briefing by arguing: “Defendants acted without legal authority when they decided to interfere with plaintiffs’ First Amendment activities, and this court should reverse the trial court, and order" it to enjoin defendant from any further infringement on plaintiffs’ First Amendment activities.”
Under the circumstances, plaintiffs have waived any claim that our state Constitution provides them with greater rights than does the First Amendment in the context of the nature of their expressive activity in this case. (Atchley v. City of Fresno (1984) 151 Cal.App.3d 635, 647 [199 Cal.Rptr. 72].)
Public property that is not by tradition or by designation a public forum may be a nonpublic forum or not a forum at all. (Arkansas Ed. Television Comm‘n v. Forbes, supra, 523 U.S. at pp. 677-678 [118 S.Ct. at pp. 1641-1642, 140 L.Ed.2d at p. 887].) A nonpublic forum arises where public property is used for communication but is not open to the general public for communicative purposes. (Ibid.) In either case, the government can restrict the use of the property to its intended purposes so long as the government acts reasonably and not merely to suppress particular points of view. (Ibid.)
In the Outdoor Advertising Act (Bus. & Prof. Code, § 5200 et seq.), the Legislature stated an intent to occupy the whole field of regulation of outdoor advertising adjacent to interstate or primary highways. (Bus. & Prof. Code, §§ 5226-5227.) Caltrans has authority to enforce provisions of the act. (Bus. & Prof. Code, § 5250.) In general, whether advertising may be permitted, and the nature thereof, depend upon things like the type of highway involved, the character of the surrounding area, and the proximity of the advertising to the highway. However, no advertising display can be placed or maintained within the right-of-way of any highway. (Bus. & Prof. Code, § 5403, subd. (a).)
Although the Supreme Court concluded the city’s residential streets are public forums, it went on to uphold the ordinance against facial challenge as being a reasonable time, place, and manner regulation. (Frisby v. Schultz, supra, 487 U.S. at p. 488 [108 S.Ct. at p. 2504, 101 L.Ed.2d at p. 434].)
For the general purposes of California’s Vehicle Code, “street” and “highway” are synonymous and are broadly defined to include every pathway publicly maintained and open to the use of the public for purposes of vehicular travel. (§§ 360, 590.) Although this definition of “street” is broad enough to include, freeways, I am not here considering an interpretation or construction of our Vehicle Code. Rather, I am applying the precedent of the *891United States Supreme Court. In declaring “streets” to be public forums, that court did not have in mind California’s Vehicle Code or definitions therein. Consequently, the Vehicle Code does not operate to expand applicable Supreme Court precedent beyond its intended reach.
“Off-site” advertising refers to the situation in which a property owner permits others, usually for a fee, to use the property to display messages, ordinarily but not necessarily commercial in nature. (See Metromedia, Inc. v. City of San Diego, supra, 32 Cal.3d at pp. 183-184.) In contrast, “on-site” advertising refers to a property owner’s display of messages from his or her own property. (Ibid.)
The decision was rendered by a four-justice plurality. Justice Douglas concurred, expressing the view that the right of commuters to be free of forced intrusions on their privacy precluded the city from transforming its transit system into a public forum. (Lehman v. City of Shaker Heights, supra, at p. 307 [94 S.Ct. at p. 2719, 41 L.Ed.2d at p. 779].)