The United States District Court for the Northern District of Ohio, Eastern Division, has certified the following question to this court pursuant to S.Ct. Prac.R. XVIII:
“Is Ohio Revised Code § 3937.18(A)(2) unconstitutional on any grounds under the facts of this case, including those stated by Plaintiff[?]”
We respond to the certified question as follows: We do not find R.C. 3937.18(A)(2) unconstitutional on any ground argued by the plaintiff.
The statement of facts as presented to this court in the federal district court’s certification order follows:
“This case involves a claim by Plaintiff, Jason Beagle, for benefits under an insurance policy issued by Defendant, State Farm Mutual Automobile Insurance Company.
“On November 23, 1994, Plaintiff was operating a motor vehicle on 1-76, eastbound, in Westfield Township, Medina County, Ohio. As Jason was proceeding on the interstate, a motor vehicle driven by Katherine Walden crossed the median and collided with the Beagle vehicle head-on. Mr. Beagle sustained serious injuries. To date, the medical bills for Jason Beagle are in excess of One Hundred Thousand Dollars ($100,000.00).
“Katherine Walden was insured by Farmers Insurance Company with One Hundred Thousand Dollars ($100,000.00) per person and Three Hundred Thousand Dollars ($300,000.00) per accident liability coverage. Jason was an insured under automobile liability policies issued by Defendant State Farm, which policies provided for uninsured/underinsured limits of One Hundred Thousand Dollars *61($100,000.00) per person and Three Hundred Thousand Dollars ($300,000.00) per accident.
“Under the provisions of amended Ohio Revised Code 3937.18(A)(2), effective October [20], 1994, Jason Beagle would not be entitled to any underinsured motorist proceeds.”
• The petitioner raises several grounds for finding that the amendment violates the Ohio Constitution. Petitioner argues that R.C. 3937.18(A)(2) invades the judiciary’s exclusive province (Section 1, Article IV) and violates the “one-subject” rule (Section 15[D], Article II), the Right to a Remedy Clause (Section 16, Article I) and the Equal Protection and Privileges and Immunities Clauses (Section 2, Article I) of the Ohio Constitution.
In addressing the petitioner’s arguments, we adhere to two well-established legal principles. The first requires that “[statutes are presumed to be constitutional unless shown beyond a reasonable doubt to violate a constitutional provision.” Fabrey v. McDonald Police Dept. (1994), 70 Ohio St.3d 351, 352, 639 N.E.2d 31, 33. The second cautions that “[t]he legislature is the primary judge of the needs of public welfare, and this court will not nullify the decision of the legislature except in the case of a clear violation of a state or federal constitutional provision. Williams v. Scudder (1921), 102 Ohio St. 305, 131 N.E. 481, paragraphs three and four of the syllabus.” Savoie v. Grange Mut. Ins. Co. (1993), 67 Ohio St.3d 500, 515, 620 N.E.2d 809, 820 (Moyer, C.J., dissenting).
The One-Subject Rule
The amendment to R.C. 3937.18(A)(2) in question was accomplished by the enactment of Am.Sub.S.B.No. 20, 145 Ohio Laws, Part I, 204, 210 (“Senate Bill 20”). The bill as originally introduced did not affect R.C. 3937.18. Its scope was limited to Revised Code sections dealing with financial responsibility law. It was only after the bill had been passed by the Senate and considered by the House on several occasions that this court announced its decision in Savoie, and that Senate Bill 20 was amended to include a legislative response.
Petitioner and his amicus curiae urge that the late amendments to Senate Bill 20 constitute legislative logrolling — the practice that the one-subject provision is intended to eliminate. Hoover v. Franklin Cty. Bd. of Commrs. (1985), 19 Ohio St.3d 1, 6, 19 OBR 1, 5, 482 N.E.2d 575, 580. Specifically, petitioner contends that the amendments related to uninsured/underinsured motorist coverage do not share the required commonality with the financial responsibility amendments of the Act to satisfy the one-subject rule.
In determining whether Senate Bill 20 passes muster under the one-subject rule, we follow State ex rel. Dix v. Celeste (1984), 11 Ohio St.3d 141, 11 OBR 436, 464 N.E.2d 153. In Dix, this court stressed the directory nature of the one-*62subject rule, holding that a judicial finding of unconstitutionality is proper only when a violation of the rule is manifestly gross and fraudulent. Id. at 145, 11 OBR at 440, 464 N.E.2d at 157. In order to find a legislative enactment violative of the one-subject rule, a court must determine that various topics contained therein lack a common purpose or relationship so that there is no discernible practical, rational or legitimate reason for combining the provisions in one Act. Id.
No doubt, Senate Bill 20 addresses multiple topics. A common thread, however, ties each of these topics together. Each amendment works as part of a legislative scheme to reduce the dangers posed by uninsured and underinsured motorists. This court recognized the nexus between financial responsibility requirements and the availability of uninsured/underinsured motorist coverage in Savoie, 67 Ohio St.3d at 507-508, 620 N.E.2d at 815, wherein the majority noted:
“This interpretation of R.C. 3937.18(G) is consistent with the concerted effort of the General Assembly to force all motorists to maintain liability insurance coverage on motor vehicles being operated within the state of Ohio. The Financial Responsibility Act requires that all motorists have the ‘ability to respond in damages for liability,’ and provides severe penalties for failure to comply. R.C. 4509.0KK).
“Regrettably, the General Assembly has not succeeded in its effort to force every motorist to maintain liability insurance coverage. * * * The purchase of full uninsured/underinsured coverage is the only possible means for responsible motorists to protect themselves and their families.”
Accordingly, we conclude that there exists a common relationship among the topics contained in Senate Bill 20, and, therefore, combination of those topics does not offend the one-subject rule.
Separation of Powers
Petitioner argues that by legislatively overruling this court’s decision in Savoie, the General Assembly usurped the exclusive province of the judiciary. Contrary to .the petitioner’s assertions, however, the Savoie court did not rely upon constitutional considerations in reaching its conclusions. Instead, the Savoie court interpreted the legislative purpose behind R.C. 3937.18.
Interpretation of the state and federal Constitutions is a role exclusive to the judicial branch. In the absence of a constitutional concern, however, the judiciary’s function is to interpret the law as written by the General Assembly. “ ‘[T]he legislature is the final arbiter of public policy, unless its acts contravene the state or federal Constitutions.’ ” State v. Smorgala (1990), 50 Ohio St.3d 222, 224, 553 N.E.2d 672, 675, quoting State v. Kavlich (1986), 33 Ohio App.3d 240, 246, 515 N.E.2d 652, 657-658 (Markus, C.J., concurring).
*63The interpretation of R.C. 3937.18(A)(2) advanced in Savoie did not meet with legislative approval. It was the General Assembly’s prerogative to redress its dissatisfaction with new legislation. See Hearing v. Wylie (1962), 173 Ohio St. 221, 223, 19 O.O.2d 42, 43, 180 N.E.2d 921, 923, overruled on other grounds in Village v. Gen. Motors Corp. (1984), 15 Ohio St.3d 129, 131, 15 OBR 279, 280, 472 N.E.2d 1079, 1081.
Equal Protection
Petitioner alleges that R.C. 3937.18(A)(2) violates the Equal Protection Clause of the Ohio Constitution because it denies “certain insurance consumers the benefit of the underinsured coverage they had purchased, while permitting others access to those benefits.” Again, we disagree.
The standard for determining violations of equal protection is essentially 'the same under the state and federal law. Beatty v. Akron City Hosp. (1981), 67 Ohio St.2d 483, 491, 21 O.O.3d 302, 307, 424 N.E.2d 586, 591-592. The preliminary step in analyzing an equal protection challenge involves scrutiny of classifications created by the legislation. “[W]here there is no classification, there is no discrimination which would offend the Equal Protection Clauses of either the United States or Ohio Constitutions.” Conley v. Shearer (1992), 64 Ohio St.3d 284, 290, 595 N.E.2d 862, 868. Moreover, “[o]nly when it is shown that the legislation has a substantial disparate impact on classes defined in a different fashion may analysis continue on the impact of those classes.” Califano v. Boles (1979), 443 U.S. 282, 294, 99 S.Ct. 2767, 2774, 61 L.Ed.2d 541, 551.
“ ‘[WJhenever the law operates alike on all persons and property, similarly situated, equal protection cannot be said to be denied.’ ” Union Sav. Assn. v. Home Owners Aid, Inc. (1970), 23 Ohio St.2d 60, 63, 52 O.O.2d 329, 330, 262 N.E.2d 558, 560, quoting Walston v. Nevin (1888), 128 U.S. 578, 582, 9 S.Ct. 192, 193, 32 L.Ed. 544, 546. Insureds carrying identical policy limits are treated the same under R.C. 3937.18(A)(2). The only classifications of insureds treated differently under R.C. 3937.18(A)(2) are those who, by contract, have chosen different policy limits.
Insureds purchase their levels of protection. If an insured purchases uninsured/underinsured motorist coverage in the amount of $100,000 per accident and $300,000 per occurrence, the insured is guaranteed total recovery for an accident up to those policy limits, regardless of the tortfeasor’s insurance status. If the insured purchases higher or lower policy limits, those limits will dictate the total recovery available stemming from an accident with an uninsured or underinsured tortfeasor.
Differences in treatment based on the individual contract between the insurer and the insured do not impinge upon a fundamental right or burden a suspect *64class. Moreover, a rational basis undeniably supports giving effect to the policy limits bargained for by the parties.
Right to a Remedy
Petitioner claims that R.C. 3937.18(A)(2) destroyed a remedy created by Savoie. Savoie, however, did not create a remedy. The Savoie court interpreted what coverage R.C. 3937.18(A)(2) then mandated. The Savoie controversy involved the amount which the insureds were entitled to receive in accordance with insurance contracts which were subject to the requirements of R.C. 3937.18. Savoie was not based on constitutional or common-law principles of full recovery in tort.
R.C. 3937.18 results from legislative policymaking. Coverage in accordance with R.C. 3937.18 is not a common-law right Any contractual right to coverage prescribed under R.C. 3937.18 does not, therefore, come within the protection of Section 16, Article I of the Ohio Constitution. Fabrey v. McDonald Police Dept., 70 Ohio St.3d at 355, 639 N.E.2d at 35; Mominee v. Scherbarth (1986), 28 Ohio St.3d 270, 291-292, 28 OBR 346, 364-365, 503 N.E.2d 717, 733-734 (Douglas, J., concurring). To the extent that the legislature may exercise its policymaking authority to alter the contractual relationship between insurer and insured to provide greater protection to the insured, it may also limit or remove those protections once given. See Byers v. Meridian Printing Co. (1911), 84 Ohio St. 408, 422, 95 N.E. 917, 919; see, also, Mominee v. Scherbarth, 28 Ohio St.3d at 292, 28 OBR at 365, 503 N.E.2d at 734 (Douglas, J., concurring).
Privileges and Immunities
R.C. 3937.18 places a statutory obligation on all motor vehicle liability insurers to offer uninsured/underinsured motorist coverage. To this extent, the parties’ freedom to contract is superseded in furtherance of important public policy concerns. In placing this obligation on insurers, the General Assembly dictates the terms of the mandatory offering of uninsured/underinsured motorist coverage. Petitioner takes issue with those portions of Senate Bill 20 that limit an insurer’s statutory obligation, claiming that those limitations violate the Privileges and Immunities Clause of the Ohio Constitution.
Because the obligation to offer uninsured/underinsured motorist coverage is rooted in public policy and imposed by the legislature, the legislature is free to delimit the obligation. By obligating all motor vehicle liability insurers in a like manner, the General Assembly does not grant special privileges or immunities. Accordingly, the Privileges and Immunities Clause is inapplicable to this case.
*65Conclusion
In accordance with the foregoing analysis, we determine that R.C. 3937.18(A)(2) survives each of petitioner’s constitutional challenges.
Moyer, C.J., and Lundberg Stratton, J., concur. Pfeifer, J., concurs in part. Douglas and F.E. Sweeney, JJ., dissent. Resnick, J., dissents and finds the statute unconstitutional.