<P> Most of the stations in the San Diego Trolley system are' at - grade' stations . There are 8 aerial stations, mostly on the newer Green Line . There is just one Trolley station in the system that is underground--the SDSU Transit Center station--also on the Green Line . </P> <P> About half of San Diego Trolley stations offer free parking (i.e. Park & Ride). Most Trolley stations offer connections to MTS bus lines . </P> <P> The San Diego Trolley's three main lines operate regular service between 5am and midnight, seven days a week . Limited service on particular segments is provided before 5am and after midnight, however; but there is no rail service between 2am and 3: 30am . During these hours when there is no passenger service, freight trains of the San Diego and Imperial Valley Railroad operate on the trolley's right of way . </P> <P> Service on the Blue Line operates every 15 minutes, seven days a week, with service every 7.5 minutes during weekday rush - hours; late - night service on this line runs every 30 minutes . The Green and Orange Lines operate service every 15 minutes on Monday - Saturday mid-days, but every 30 minutes on weekend mornings, on Sundays, and during evenings . </P>

San diego trolley how late does it run