ordered a fleet of 65 specialized Siemens S70 US ("Ultra Short") vehicles, which retain the low-floor design but would be the same length as the SD-100 vehicles. In 2016, San Diego ordered an additional 45 specialized LRVs, this time the Siemens S700 US, which has a redesigned center section, with longitudinal seating (passengers facing the aisle) instead of the S70's more traditional seating with passengers sitting four-across, facing forward or back, with an aisle in between. This change, was made to eliminate a seating layout that had been criticized as cramped and ease the movement of passengers within that section. The San Diego Trolley ordered an additional 25 S700 US vehicles in 2019, scheduled for delivery by the end of 2021. Current rail fleet Specifications Below are the technical specifications of the system's five different fleet series of light rail vehicles:. In addition to the aforementioned vehicles, two heritage Presidents Conference Committee (PCC) streetcars from 1946 operate on the Silver Line. Car 529 has been operating on the Silver Line since its opening in 2011. Car 530 has been operating on the Silver Line since March 2015. An order was placed in mid-2019 for 25 more S700 light rail vehicles, in addition to the 45 S700s ordered in 2016 and delivered in 2018–2020. Floor plans Below are the floor plans of the system's five different models of light rail vehicle, comparing the various sizes and interior layouts: See also San Diego and Arizona Eastern Railway San Diego Electric Railway San Diego Metropolitan Transit System List of bus routes in San Diego San Diego Transit Santa Fe Depot (aka. Union Station) Coaster (commuter rail) Pacific Surfliner List of United States light rail systems by ridership List of rail transit systems in the United States Light rail in the United States List of North American light rail systems by ridership Light rail in North America North County Transit District Sprinter (light rail) Transportation in San Diego County Transportation in San Diego Notes References Sources Gena Holle, The San Diego Trolley, Interurban Press (1995); "Guideway Planning Project Final Report" MTDB (1978); "Report on Feasibility of Using Existing SD&AE ROW for Commuter Service" San Diego County (1978); MTDB publicity materials including "San Diego Trolley, Inc. Summary" (1997), MTDB Progress Report 1976–1986; Pacific Southwest Railway Museum, San Diego & Arizona Railway. External links Official Metropolitan Transit System website San Diego Electric Railway Association San Diego