Two of North America's largest railroads have prevented Montreal from electrifying the city's four commuter rail lines on tracks owned by freight rail. They claim that electrification would pose insurmountable structural problems for freight rail.
Sep 18, 2012 The Montreal Gazette
A $14.6 billion package of rail improvement projects, called the "biggest modernisation of our railways since the Victorian era," has been announced by the UK's governing coalition.
Jul 16, 2012 BBC News
The Federal Railroad Administration does not allow for the mixing of train types for safety reasons, which proved a key obstacle for Caltrain's plan for electrification. As a pilot project,they are allowing the line to utilize electric multiple units
May 30, 2010 Mercury News via Palo Alto Daily News
That's the verdict from a report released April 22 by officials of Caltrain, the nearly 150-year-old commuter line connecting San Francisco, San Jose, and Peninsula suburbs. In turn, the key to electrification is cooperation with the CA HSR Authority
Apr 26, 2010 San Jose Mercury News