The Metropolitan Transit System board approved Thursday the $205 million purchase of 57 light rail vehicles that won't block intersections in downtown San Diego."This is a major purchase of new vehicles and allows MTS to bring the convenience of low-floor light rail vehicles to our entire system," said Harry Mathis, chair of the MTS board."It also marks the beginning of (a) rehabilitation project for our Blue and Orange lines to significantly enhance our operations and customer experience," he said.The 60-passenger light rail vehicles are 81 feet long, nine feet shorter than existing ones, and will allow the use of three-car trains on C Street in downtown without blocking intersections, according to MTS.San Diego Trolley cars along C Street now often stick a couple of feet into intersections, impeding pedestrians and cars.The rail cars, which are manufactured by Siemens Transportation Systems in Sacramento, also utilize low-floor technology that makes it safer and easier for passengers to board.Delivery of the first vehicles is expected in late 2011. The $205 million cost of the light rail vehicles will come from TransNet sales tax revenue and through a statewide voter-approved bond for transportation projects, according to MTS.The purchase is part of a rehabilitation project along the San Diego Trolley's Blue and Orange lines that includes improved station platforms, replacing old rails and overhead electrical contract wires and improving switching, signaling and crossovers. Work on that project, which will cost $234 million, is expected to begin early next year and be completed in 2013.