Opinion Per Curiam.

OPINION ON REMAND

In 1975, this Court decided District of Columbia, et al. v. Train, 172 U.S.App.D.C. 311, 521 F.2d 971 (1975), which upheld in part and vacated in part transportation control regulations promulgated by the Administrator of the EPA. This case, along with decisions of the Fourth and Ninth Circuits,1 was considered by the Supreme Court in Environmental Protection Agency v. Brown, 431 U.S. 99, 97 S.Ct. 1635 (1977). The Court vacated the judgments of all three circuits and remanded the cases to the respective courts for consideration, inter alia, of the question of mootness. On August 7,1977 the Congress enacted extensive amendments to the basic act (Clean Air Act Amendments of 1977, Pub.L.No. 95-95, 91 Stat. 685 (Aug. 7, 1977)). On remand we issued our opinion of August 19, 1977, finding that the controversy addressed in our 1975 opinion was moot and dismissing the appeals. Various motions have since been filed with respect to our August 19, 1977 disposition and upon reconsideration thereof we vacate our August 19, 1977 opinion in District of Columbia, et al. v. Costle, Nos. 74-1013, et al., and replace it with the following orders.

I. THE BICYCLE LANE AND RETROFIT REGULATIONS

With respect to the regulations2 concerning the creation of a network of *100bicycle lanes and the regulations concerning retrofit of various classes of vehicles, our 1975 opinion held:

To the extent that the bicycle lane and storage facilities regulations order the states to enact statutes and regulations, they are vacated as in excess of the Administrator’s powers under the Clean Air Act. The remainder of the bicycle lane regulations are remanded to the Administrator because of an absence of evidence in the record supporting the need for such facilities and their feasibility.

172 U.S.App.D.C. at 338, 521 F.2d at 998. In the same opinion with respect to the retrofit regulations, we held:

The . . . retrofit regulations are vacated to the extent that they have been held to be in excess of the Administrator’s powers under the Act or to be unconstitutional, and are affirmed to the extent they prohibit the states from registering non-conforming vehicles and prohibit vehicle owners from operating them. These . . . regulations are remanded to the Administrator with directions that he take prompt action to promulgate complete and enforceable regulations to replace the deficient implementation plans submitted by the states.

172 U.S.App.D.C. at 338-9, 521 F.2d at 998-99.

These decisions with respect to the retrofit and bicycle lane regulations were not appealed to the Supreme Court. In fact, no action has been taken with respect to these regulations since we issued our 1975 opinion. Since our decisions referred to above were not appealed, we order the reinstatement of our 1975 judgment with respect to retrofit and bicycle lane regulations, and that said portion of the case be remanded to the Agency for reconsideration and modification of the regulations in accordance with our aforesaid 1975 opinion and as may be legally required by subsequently enacted legislation.3

II. BUS LANES

Our 1975 opinion affirmed the regulations concerning the establishment of exclusive bus lanes, 521 F.2d at 998. Virginia appealed, inter alia, our holding on bus lanes.4 The Supreme Court, in vacating our judgment and remanding the ease to determine whether it was moot, did not refer to any change of position, any modification by the Agency, or any other factor that suggests our decision with respect to the bus lanes should be altered in any respect. It appearing that Virginia’s concern with respect to bus lanes is not moot, we reaffirm our 1975 holding on bus lanes and remand this portion of the case to the Agency for such consideration as may be legally required,5 so that the Agency might issue a final order setting forth its decision thereon.6

III. VEHICLE INSPECTION AND MAINTENANCE

With respect to the regulations concerning vehicle inspection and maintenance, our 1975 opinion held:

*101The inspection and maintenance regulations . . . are vacated to the extent that they have been held to be in excess of the Administrator’s powers under the Act or to be unconstitutional, and are affirmed to the extent they prohibit the states from registering non-conforming vehicles and prohibit vehicle owners from operating them. These latter regulations are remanded to the Administrator with directions that he take prompt action to promulgate complete and enforceable regulations to replace the deficient implementation plans submitted by the states.

172 U.S.App.D.C. at 338-9, 521 F.2d at 998-99. The Solicitor General petitioned the Supreme Court for review of this holding but challenged the judgments of all three circuit courts “only insofar as they invalidated the regulations requiring state inspection and maintenance programs.” 431 U.S. at 103, 97 S.Ct. at 1637. Prior to argument, however, the Solicitor General conceded the necessity of removing from the regulations all requirements that the States submit legally adopted regulations, even though he insisted that the regulations contained no requirements that the states adopt laws. Id. Acting upon this representation, the Court stated: “We decline the federal parties’ invitation to pass upon the EPA regulations, when the only ones before us are admitted to be in need of certain essential modifications. Such action on our part would amount to the rendering of an advisory opinion.” 431 U.S. at 103-04, 97 S.Ct. at 1637 (emphasis added). The Court then vacated the judgment of this court and remanded the case, as described above.

On June 15, 1977, over a month after the Supreme Court’s decision in EPA v. Brown, the EPA modified its inspection and maintenance regulations so as to remove (1) requirements that the states adopt regulations, (2) references to state legislative activity, and (3) certain details concerning implementation of the program and other administrative concerns. 42 Fed.Reg. 30504, 30507-09 (1977). It is our opinion that these modifications substantially modify those regulations previously in force which were the subject of this court’s 1975 opinion and serve to alter the issues raised in the prior appeal to the extent of the changes described above. Therefore, most of the issues raised by the prior petition became moot; but some of the issues continue to be the subject of genuine controversy between the parties, and it therefore appears that the case is not moot in this respect. Therefore, the inspection and maintenance regulations aspect of the case is remanded to the Agency to permit the parties to pursue their administrative remedies on a new record.7

We have issued a separate order this day staying further proceedings in District of Columbia v. Costle, No. 77 — 1578, petition for review filed July 1, 1977; Virginia v. EPA, No. 77-1617, petition for review filed July 14, 1977; and Maryland v. Costle, No. 77-1622, petition for review filed July 15, 1977, until the termination of the Agency’s proceedings on remand with respect to the inspection and maintenance regulations.

So ordered.