NCTD's SPRINTER is 22 mile long DMU Light Rail Line that runs along and restored service to the Escondido Branch of the Santa Fe Railway from Oceanside to Escondidio on March 9, 2008 which had passenger service discontinued in 1946. The line follows this grade except for the 1.8 mile elevated San Marcos Loop. The line uses Siemens VT642 Desiro Articulated DUM units, widely used in Europe but not compliant with the FRA for use in mixed traffic in the United States. This means train service operates on only half-hour headways (on weekends early morning and evening service is hourly) starting from the retrospective terminals at 4:00am with the last trains leaving quite early at 8:30pm Sunday thru Thursday to allow for BNSF freight operations in the overnight hours (a local about three times per week). Friday and Saturday night service is extended until about 11:00pm. The line is a mixture of single and double track and only allows for a half-hour headway. Scheduled total travel time for the route is 56 minutes. It's operations and rolling stock are extremely similar to New Jersey Transit's River LINE although SPRINTER lacks any street running. It does have plenty of grade crossings all with crossing lights, bells and arms. Each station is long enough to platform hold two car trains although just one cars are normally run. The line has high-platforms at all stations and to avoid clearance issues from passing freight trains (and so employees can ride outside of the trains) all stations (except for the two terminuses and Cal State San Marcos on its own short SPRINTER dedicated branch) have four gap fillers that are raised at night (electronically, I assume, controlled remotely) for freight services and directly line up with the DMU doors which each have there own little gap filler bridge plates that automatically deploy when a door opens. All of the platform edges (and even the 3 non-shared platforms) have low black fences except where the gab fillers line up with the doors, a quite unique design. The surface of these gap fillers is nearly entirely a yellow tactile warning strip. Other lines with this same issue of shared freight train use (for example Portland's WES Commuter Rail and a few New Jersey Transit high-level platform stations) use gauntlet track instead. The River LINE avoids the issue by having lower floor DMUs.

Midnight, March 8th, 2013: SPRINTER service has been suspended for two to four months as a safety measure because of premature ware of disk breaks on the DMUs. Parts for these trains have to be sent from Europe and the root cause is still under investigation. Replacement Local/Express Bus Service operates.

Saturday, May 18, 2013: Service is restored after its 2 and a half month suspension.