Pittsburgh's T (light rail) runs on 650 volts DC through a single overhead line and grounded rails. In the early 20th Century, PRR's Eastern Corrdior ran at 12,000 volts, 25 Hz AC, but those powered full-size trains.
The only issue with tired vehicles is that you need dual overhead lines to complete a circuit. This wouldn't be a huge issue to set up, but I would think they use AC to minimize arcing, or at least they should (unlike DC, AC goes to zero volts twice a cycle, allowing for an arc to break).
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
Driving electric since 2-21-2013.
3 years with the i-MiEV and loving every mile!