The Metropolitan Transit System (MTS) made history on May 8, 2008 by providing Trolley service to over half a billion riders. From its inception in 1981, Trolley ridership has grown from 10 million riders a year to over 36 million riders and climbing.

Elsa Padilla was riding the Blue Line to work at the YMCA when she was selected as the San Diego Trolley's Honorary 500,000,000th Rider. MTS Board of Directors Chairman Harry Mathis awarded Padilla with a commemorative prize package that included an official MTS certificate, six months of free MTS ridership and giveaways by the USS Midway Museum, The San Diego Padres, Coca-Cola, Balboa Park and the San Diego Symphony.