[2] To test the technology to be used on the system, in 2007, SANDAG selected a series of streets in University City to be fitted with transit signal priority, in addition to building stations with real-time arrival displays.

The Rapid branding was announced in 2013, with the new buses arriving in December of that year, with corridor testing and driver training beginning the following January.

On May 17, 2014, the buses were accepted for passenger occupation, and in-service testing began on route 20 during a record-breaking heatwave caused by the Santa Ana winds at the time.

The remaining routes would be discontinued altogether with June 6, 2014 being the final date of operation for the Premium Express network.

On January 28, 2021, it was announced that MTS, in cooperation with the North County Transit District, would begin offering free rides for passengers en route to receive a COVID-19 vaccine, by carrying a confirmation paper for their appointment.

The agency also switched to Biogas, a renewable form of CNG as an interim measure until the electric transition is completed in 2040.

The Rapid Express service operates from selected bus stations to downtown San Diego, bypassing City Heights and Kearny Mesa.

Additionally, Routes 201, 202 and 204 provide SuperLoop service between UC San Diego and the Westfield UTC mall.

Routes 201 (counter-clockwise) and 202 (clockwise) connect UC San Diego and Westfield UTC on a loop that passes through La Jolla Village, north University City, and the Jacobs Medical Center complex, while Route 204 serves the office parks and apartment complexes due east of UTC in a clockwise loop.

The buses used on this route are vinyled into the Rapid livery, but feature regular local-style transit bus seating instead.

[14] Connection to San Diego Trolley Connection to other Rapid routes Parking is available The South Bay Rapid (Route 225) began limited peak-hour service on September 4, 2018 between the East Palomar Park and Ride in Chula Vista and downtown San Diego.

Throughout its planning, the route sparked controversy mainly by HOAs due to its bisection of the Otay Ranch and Eastlake communities and its proximity to nearby homes.

[18] The buses used on this route feature intercity coach-style seating, but have silver-colored destination displays on the outside compared to the rest of the fleet, which have amber ones.

The SDMTS Rapid Route 227 started service on October 15, 2023, although construction completion with full implementation is expected by Late 2024.

It also eliminates a transfer at Del Lago Transit Center between Route 20 and Breeze Rapid to central Escondido.

[22] The cost for the initial operating segment is approximately $238 million, consisting primarily of transit centers at City Heights, Del Lago, Escondido, and Rancho Bernardo; parking structures at Miramar College and Sabre Springs; and new 60-foot buses.

Taxpayer advocates have supported the Rapid due to its lower cost compared to rail extensions at the time.

Early concept maps of the South Bay Rapid revealed the possibility of additional CenterLine stations in the medians of I-805 and SR 94.

The first shelter was installed on the inbound side of the Ruffin stop in 2017, next to the Kaiser Permanente San Diego Hospital.

This Demonstrates MTS committed to be in compliance with Initiative Clean Transit, a proposed California law that could result in full electrification by 2040.

On June 22, 2018 SANDAG announced that it has seized control of a block of land currently occupied by an auto maintenance facility, a law firm and a car park.

The fleet is maintained at the system's Imperial, Kearny Mesa, East County and South Bay divisions.