Associate Professor of Urban Planning Michael Manville spoke to the San Diego Union-Tribune about the anticipated effects of a new trolley line in San Diego. The 11-mile trolley runs from Old Town to UTC mall in La Jolla and is expected to carry 20,000 daily riders in the coming years. While the trolley line may seem like an ideal solution to reduce traffic congestion in the area, Manville explained that all the cars the trolley removes from the freeway “will almost certainly get replaced by backfilling prompted by reduced congestion” as open space on the freeway is filled by new commuters. “It’s a very established empirical fact that new transit doesn’t alleviate traffic,” Manville said. “It’s self-undermining, because congestion is the No. 1 thing that blunts demand.” He agreed that the new transit line is good for the economy and the region but noted that “you need to be realistic about what transit can and can’t do.”