The main system uses an unusual broad gauge (mostly seen in India and Pakistan) and mostly ballastless track. Originally using flat-edge rail and wheelsets with cylindrical treads, BART is now switching to conical tread to reduce the noise caused by flange/rail contact and loss of adhesion of one of the wheels on curves. DC electric current at 1,000 volts is delivered to the trains over a third rail. An automated guideway transit line and an additional station were opened in 2014 and use off-the-shelf cable car technology developed by DCC Doppelmayr Cable Car: the Cable Liner. The section of the Antioch-SFO/Millbrae line east of the Pittsburg/Bay Point station runs on conventional unelectrified rail.