In additions to long term changes in locomotive fleet acquisition to improve fuel efficiency, the energy crisis caused the RR's to shut down engines to save fuel, as the most obvious thing to do. Prior to that engines had been left running without much thought about fuel use of costs.

This "shutdown" all engines not in use policy also resulted in immediate reductions in the nitric acid burning your skin and peeling your car paint at night at Taylor..... as suddenly you didn't have a hundred plus engines sitting there idling at any given time, and the place became a lot quieter at night.

The gas crisis also suddenly filled up what was left of America's passenger trains, like Amtrak's San Diegan's. This probably saved Amtrak and American intercity rail passenger service from likely destruction...... This gave impetus to the reintroduction of light rail, in places like San Diego, and the development of commuter rail, with the 1974 Baxter Ward proposals.

It took a second such "gas crisis" in 1979/80 and many years of relatively high fuel costs to reinforce some of trends, and for voters to begin approving more funding for transit.