http://en.wikipedia.org/wiki/Public_Utility_Holding_Company_Act_of_1935
PUCH Killed Interurbans because Uitility Companys could not hold Streetcar Lines and the Power companys that suplied them at the same time.
In Practice the Utlities used Railroad condemnation and interurban right of ways to gain right of way for high volatage power lines, The Interurbans and the fares from that were a added bonus. After 1935-1940 Most Interurbans had ripped up there tracks but the Power companies kept the right of ways for there power lines… Today for intstance…a power lines parrel the North Shore bike trails and in Akron OH the Ohio Edison Parrels interurban lines…
Now with the repeal of the act… this would allow Electric Utilities to directly own Railroads as well as power them with electricty to bring power to them to haul coal to the power plants as well as vice versa.
Publicly owned Public Utlilitys (like New York Power Authrity) could now control light rail aas well as heavy rail transit lines in the State of New York and use there own power to operrate them were before the repeal of PUCH they would have to puchase power to run there trains and the trains would have to be run by a seprate entity