I respectfully dissent from the majority opinion. It relies heavily upon a rehearing opinion in Public Service Commission v. C.I. & L. RR. (1956), 235 Ind. 403, 134 N. E. 2d 53. The opinion in the latter case upon the merits, however, contains the following statement at page 397:
“The trial court1 may not set aside an order of the Public Service Commission if it is supported by substantial evidence and is not contrary to law. * * * ” (Emphasis supplied)
This statement of law must be considered in understanding the language used by Judge Arterburn in his rehearing opinion wherein he stated that the court has no right to substitute its judgment on the merits of an issue before the Public Service Commission which has acted within its jurisdiction. The C.I. & L. RR. case, supra, affirms a decision of the trial court upon the ground that since the appellant Public Service Commission did not present to the Supreme Court the evidence which was presented before the Commis*663sion or the evidence presented before the trial court, the Supreme Court had no opportunity to determine whether or not the Commission order was supported by substantial evidence or was contrary to law.
The reluctance of this court to recognize the distinction between “main tracks” and “main line tracks” is understandable because the distinction perhaps is difficult to isolate and articulate. Such reluctance, however, does not justify the court’s failure to recognize it. The majority has said that it was appropriate for the Commission to equate the “main track” referred to in Ind. Annotated Statutes § 55-1326(m), (Burns’ 1951 Repl.), with the “main line track” covered in the exclusionary provision under Ind. Annotated Statutes § 55-1326(a), (Burns’ 1951 Repl.). Such equation is not so obvious to me as apparently it is to my brethren.
To the contrary, I would point out that a separate statutory provision, i.e., the Utility Tax Act of 1949, being Ind. Annotated Statutes §64-1810(1), (Burns’ 1961 Repl.), quite clearly recognizes that there is a difference between “main lines” and “main tracks.” I cannot convince myself that the legislature at one point intended main lines and main tracks to be synonymous yet in another context to have separate and distinct meanings.
Further, while Union Pacific R. Co. v. Anderson (1941), 167 Ore. 687, 120 P. 2d 578, relied upon as principal authority by the majority here, does not consciously differentiate between “main line track” and “main track”, it does, nevertheless dramatically emphasize that “main line” has a very fixed and distinctive meaning. By unshakeable inference, that case constitutes logical and rational authority which, in my view, requires this court to reject appellee’s contention that, as the Commission concluded, “main track” and “main line track” are synonymous. The Oregon Supreme Court there said:
“The commonly understood meaning of the words ‘main line’ of a railroad is the principal line, and the branches are the feeder lines like the tributaries of a river. The court *664so stated in the Oregon, C. & E. case quoting dictionary definitions to that effect. It also quoted from 22 R.C.L. 744 the following: ‘A “trunk railway” is a commercial railway connecting towns, cities, counties or other points within the state or in different states, which has the legal capacity, under its charter or the general law, of constructing, purchasing and operating branch lines or feeders connecting with its main stem or trunk, the main or trunk line bearing the same relation to its branches that the trunk of a tree bears to its branches, or the main stream of a river to its tributaries.’ ” 120 P. 2d 588.
As is made clear in the Oregon decision, such determination is not one of fact as the majority holds here, but is one of law. And it is, I believe, well-established as stated in 2 Am Jur 2d, Administrative Law, § 676 that:
“An administrative determination of questions of law is not binding upon a reviewing court. Such a determination is subject to judicial review upon which the court may substitute its own judgment and exercise an independent judgment as to the correctness of the determination * * * ”
It is our duty, therefore, to review the legal conclusion drawn, erroneously I believe, by the Commission. Finding No. 6 made by the Commission, not found in the majority’s recitation, impliedly controverts the legal conclusion that “main line track” can be here held to include more than the main artery or main trunk trackage. Said Finding is as follows:
“6. That IHB’s function is to provide switching service to the industrial area in and around Chicago, Illinois, and Lake County, Indiana, and to transfer cars between other railroad carriers intersecting the segments over which the IHB operates. Exhibit 1, p. 4. The IHB has been able to accomplish this function by formation of an east-west artery or trunk between Franklin Park, Illinois, to Gibson, Indiana, by acquiring trackage rights over segments which it does not own or lease. See Exhibit D. This east-west artery or trunk is intersected by several lines which serve to carry traffic to and from industries and a few railroad carriers not located on the east-west artery or trunk. In some instances the IHB only has trackage rights to oper*665ate over these lines, while other of these lines are owned or leased. See Exhibit C, and Exhibit 1, pp. 6, 14 and 15.”
As demonstrated by the Oregon case, supra, “main line track” is that track which forms the main artery or trunk of the railroad. The Indiana Public Service Commission in its Finding No. 6 found as a fact that the main artery2 of the Indiana Harbor Belt Railroad runs from Franklin Park, Illinois to Gibson, Indiana. This track mileage within Indiana is admittedly less than the 41.91 miles of Indiana track which the Commission found to exist as “main line track” for purposes of the Full Crew Law.
As appellant itself admits, however, “in determining what does constitute that main trunk line or artery, a factual determination must be made”. As held in PSCI v. C.I.&L RR. Co., supra, at page 403:
“ * * * [A] reviewing court may remand a case to the administrative body for further proceedings in conformity with the law as defined by the judgment and decision of the court, [citations omitted]
“Remanding it to the administrative body gives it an opportunity to correct the irregularities in its proceedings as determined by the court. At the same time it avoids the court’s encroachment upon its administrative functions. There is no more reason for assuming that the commission will disregard the law as fixed by this reviewing court than that a lower trial court will do so.”
Upon remand the factual determination made by the Commission in its Finding No. 6 could well be deemed erroneous in the light of the guidelines set forth in the Oregon case, supra, and as proposed by this dissent.
In its Finding No. 9, the Commission found that “it is not necessary to count separate parallel tracks located between the same termini in order to determine the length of the main line track of the IHB Railroad in the State of *666Indiana”. The parties in this regard had stipulated that, as to the main artery referred to in Finding No. 6, the length of trackage in Indiana exclusive of separate parallel tracks, between the Indiana-Illinois State Line and Ivanhoe, which lies east of Gibson, is 5.69 miles. The length of the main artery trackage, being that located between the State Line and Gibson, is therefore necessarily less than 5.69 miles. Further, it is not inconceivable that upon redetermination the Commission might find that a north-south main artery exists. The Commission, therefore, might well find the main artery or arteries of Indiana Harbor Belt Railroad to consist of more trackage or less trackage than exists between the Indiana-Illinois State Line and Gibson, Indiana. In this regard, I wholly agree with the majority that trackage of any description located outside the State of Indiana may not be considered in computing “main line tract” as that term is used in the Full Crew Law. If such factual determinations were made, however, within these guidelines, it would, as Judge Sharp’s opinion indicates, be binding upon us. Such determination would necessarily depend upon the nature and extent of operations upon the trackage considered.
For the foregoing reasons, I would reverse the decision of the Commission and remand the cause for rehearing and redetermination.
Note. — Reported in 263 N. E. 2d 292.
. Prior to enactment of tbe Acts of 1957, ch. 189, § 13, being Ind. Annotated Statutes §54-448 (Burns’ 1969 Supp.), appeals were permitted de novo to the circuit or superior courts of Marion County.
. The findings are silent as to the existence, if any, of a north-south artery or trunk thereby indicating that no such north-south artery exists in the opinion of the Commission.