 Most of the park-and-ride buses run in barrier-separated high-occupancy-vehicle (HOV) lanes that provide direct service from park-and-ride parking lots to major employment destinations.Prior to the opening of METRORail, Houston was the largest city in the United States without a rail transit system.Following a successful referendum held locally in 2003, METRO is currently in the beginning design phases of a 10-year expansion plan to add five more sections to connect to the current rail system.