San Joaquin Regional Transit District (known as "San Joaquin RTD" or simply as RTD) is a transit district that provides bus service to the city of Stockton, California and the surrounding communities of Lodi, Ripon, Thornton, French Camp, Lathrop, Manteca, and Tracy. In 2023, the system had a ridership of 2,432,000, or about 9,100 per weekday as of the fourth quarter of 2023.

San Joaquin RTD operates 26 local fixed routes to the Stockton metropolitan area, including five BRT Express routes, RTD’s Bus Rapid Transit service. San Joaquin RTD also operates seven Metro Hopper routes that provide fixed route and complimentary deviations for ADA certified passengers and five County Hopper routes that travel to neighboring cities in San Joaquin County. County Hoppers, like Metro Hoppers are fixed routes with complimentary deviations for ADA certified passengers. Finally, they operate Commuter services includes two routes that serve Sacramento and the East Bay (Dublin/Pleasanton’s BART station), with subscription service available for commuters.

In 1963, legislative groundwork began for the establishment of a public transit special district in Stockton, and in 1965, the Stockton Metropolitan Transit District (SMTD) began providing service for the residents of Stockton. In late 1979, SMTD moved operations from Grant and Channel Streets to its current Lindsay Street facility. In 1985, SMTD adopted the nickname “SMART.” In 1990, SMART began providing fully accessible fixed route and Dial-A-Ride services for the elderly and persons with disabilities under the Americans with Disabilities Act (ADA) of 1990. In 1994, enabling legislation expanded SMART’s service area to the San Joaquin County border, bringing with it a name change to reflect its expansion – San Joaquin Regional Transit District, or SJRTD for short. That same year, SJRTD expanded its Interregional Commuter service to offer additional routes to commuters traveling to the Bay Area and Sacramento. In 2004, SJRTD adopted “San Joaquin RTD” as its new corporate identity and developed a new logo. That same year, RTD introduced low-emission diesel-electric hybrid buses via its “Flower Bus,” with a full-wrap sunflower display designed to complement the slogan “A Breath of Fresh Air.” At the end of 2006, RTD opened the Downtown Transit Center for the public, with a floor for employee offices. In 2017, by converting its route 44 to electric buses, RTD became the first transit agency in the United States to operate a fully electric BRT route.

A consolidated transportation agency that was formed by local transit agencies and the San Joaquin Council of Governments in San Joaquin County, RTD was designated to be the CTSA for San Joaquin County. The local agencies that make up the board of the CTSA are:

• Escalon eTrans
• Ripon Blossom Express
• City of Lathrop
• City of Lodi Grapeline
• Manteca Transit
• Tracy Tracer
• RTD

Programs that are currently offered include:

• Centralized location for ADA Assessment for Paratransit (Dial-a-Ride) services for all transit agencies in the county.

Centralized location for Discount Fare Card assessment for senior citizens, people with disabilities and Medicare Card holders in the county.

• Access Pass (Formerly the FREEdom Program): Allows all ADA Paratransit qualified passengers to ride most fixed route services offered by transit agencies in the San Joaquin County. All passengers who have been certified through Access San Joaquin will receive a Photo ID card. Passengers will show this card to bus operators to board as paid fare.

• Discount Fare Cards: Available to those with disabilities and Senior Citizens (60 or older for residents those living in Stockton, Lodi or Ripon; 62 or older for residents of Manteca, 65 or older for residents living in Tracy and Escalon.

• Travel Training: Someone with extensive knowledge of the transportation agencies will work together with senior citizens and passengers with disabilities to learn how to use the fixed route systems.

• RTD Van Go!: RTD's own Ride Share or Mobility on Demand service, similar to RTD Go! Difference is that multiple passengers may ride in the same vehicle to different destinations. Currently serves the entire San Joaquin County^[3] The service hours are from:
  • 8:00 a.m. to 5:00 p.m. Weekdays and weekends

• My Ride: A fuel reimbursement program for ADA certified passengers, for traveling to medical appointments in the San Joaquin County. ADA certified passengers can use this service option to choose their family and or friends to take them to their medical appointments. Passenger and Driver complete waiver forms, once forms are turned in, they are enrolled in the program.

For more information visit the Access San Joaquin Web Page

BRT Express is RTD's express bus service and uses uniquely branded, low-emission diesel–electric hybrid buses that arrive at their stops every 15 minutes during weekday peak hours and every 30 minutes on weeknights, weekends, and holidays. BRT Express passengers are required to have a valid, pre-paid RTD bus pass or ticket to ride. Fare vending machines, located at BRT Express stops and the Downtown Transit Center (DTC), are available for passengers to purchase single ride, day, and 31-day passes. BRT Express uses the same fare structure and passes as RTD’s regular fixed routes and passes issued by the Fare Vending Machines can be used on any of RTD's regular fixed routes.

Completed December 2006, the DTC at 421 E. Weber St. has three off-street bus lanes, two passenger boarding platforms, and a two-story building. Nearly all RTD routes connect at the DTC, which has 20 sheltered, off-street bus stops as well as additional street side stops on the north and south sides. The DTC building incorporates the façades of three historic buildings (Hart & Thrift, Bower, and Delta) on its front elevation. The first floor of the DTC has a waiting area, public restrooms, and a customer service center where riders can get maps and schedules, purchase fares, and make customer comments. RTD leases 2,100 square feet (200 m²) of retail space for a restaurant on the east end, and a police satellite station provides the DTC with two RTD-contracted police officers. A boardroom available for public meetings occupies the west end of the first floor and RTD administrative offices occupy the rest of the building. As of April 2, 2018, in partnership with RTD, Greyhound now uses the DTC as its Stockton, California stop.

On average, 6,000 people use the DTC each weekday.

In 2018 RTD introduced their first all-electric bus route. RTD plans to have a fleet of all electric buses by 2025. The current fleet of all-electric buses as of today, are manufactured by Proterra Inc and Gillig. RTD will be receiving a hydrogen fuel bus from NFI Group in 2024 that they will be testing.

As of 2023 this is RTD's Active Route List