# Tri Delta Transit

Tri Delta Transit, formally the Eastern Contra Costa Transit Authority, is a joint powers agency (JPA) of the governments of Pittsburg, Antioch, Oakley, Brentwood, and Contra Costa County that provides bus service for the eastern area of Contra Costa County, California, United States. In 2024, the system had a ridership of 1,348,100, or about 4,500 per weekday as of the fourth quarter of 2024.
Tri Delta Transit local buses connect to the BART rapid transit system at Antioch, Pittsburg Center, Pittsburg/Bay Point and Concord. In addition, Tri Delta Transit buses connect with Amtrak commuter rail services, including San Joaquins and Capitol Corridor. Within the county, Tri Delta Transit buses connect with other local bus services, including County Connection (serving central Contra Costa County) and WestCAT (western Contra Costa County).

## History

The Eastern Contra Costa Transit Authority (ECCTA) JPA was formed in 1976 by the cities of Antioch, Brentwood, and Pittsburg, along with the County of Contra Costa. When Oakley was incorporated in 1999, the JPA was amended to admit Oakley in 2000.$^{:1}$ The Tri Delta Transit name was selected in May 1977 by the marketing committee of the ECCTA.
Tri Delta Transit fixed route service began on June 6, 1977, celebrated by an inaugural bus starting from Antioch City Hall (10 a.m.), traveling to Oakley (10:30), Brentwood City Hall (11), Pittsburg, and ending in West Pittsburg (2 p.m.). For the first week, free rides were offered. Initial service was provided for two local routes in Antioch and Pittsburg, which connected with express bus service serving BART. AC Transit operated the service under contract until 1984, when it was transferred to a private operator,$^{:1}$ and ECCTA acquired its first buses; prior to that, AC Transit owned the buses it used for Tri Delta Transit. Some of the buses used in 1978 included 29-foot models, shortened from 35-foot buses at the AC Transit shops.
Dial-a-ride on-demand transit services have been provided since 1979 using contracted private operators. ECCTA consolidated fixed route and on-demand services with a single operator when the contract with AC Transit was discontinued in 1984.
The ECCTA headquarters in Antioch was built in 1987, consolidating administration, operations, and maintenance at a single facility; expansions in 2004 provided additional space and bus parking.$^{:1}$

## Overview of fixed-route service

Tri Delta Transit operates in eastern Contra Costa County and has stops in Antioch, Oakley, Brentwood, Bay Point, Pittsburg, Martinez, and Concord. Tri Delta Transit operates local and express routes on weekdays and local routes on weekends and holidays.

### Transfers

Intra-system transfer points for the majority of Tri Delta Transit's routes include:
* Brentwood Park & Ride in Brentwood
* Oakley Park & Ride
* Antioch BART station in Antioch
* Pittsburg Center BART station in Pittsburg
* Pittsburg/Bay Point BART station in Pittsburg
* Los Medanos College in Pittsburg
In addition to transfers within Tri Delta Transit and to BART, riders may transfer to neighboring and long-distance public transportation systems at other stations, including:
* Antioch–Pittsburg station, via Routes 387 and 388
** Amtrak San Joaquins
* Concord BART, via Route 201X (weekdays)
** County Connection
* Martinez station, via Route 200X (weekdays)
** Amtrak California Zephyr, Coast Starlight, San Joaquins, and Capitol Corridor
** County Connection
** WestCAT

### Route list

Tri Delta Transit operates sixteen bus routes on weekdays, serving the cities of Bay Point, Pittsburg, Antioch, Oakley, and Brentwood, with one route each connecting to Concord (201X) and Martinez (200X). Most routes parallel the San Joaquin River, running east and west; routes designated as "express" (200X, 201X, 202X, and 300X) are designed with fewer stops and operate primarily during commute hours with limited mid-day service. Several routes share the same terminal points, but take different paths to provide service to communities both north and south of California State Route 4. For example 380, 387, 388, and 390 all provide service between the Pittsburg/Bay Point and Antioch BART stations, with 388 continuing on to the Antioch Medical Center.
On the weekends and holidays, Tri Delta Transit operates six routes, which are a subset of five weekday routes and one additional route (395) that operates exclusively on weekends, throughout the ECCTA service area including the aforementioned cities with the exceptions of Concord and Martinez. The five routes that operate all week are longer, local routes which duplicate coverage of the shorter weekday-only bus routes.
Tri Delta Transit bus routes :
| Route | Westbound Terminal | Eastbound Terminal | Weekend service |
| 200X | Martinez station (Amtrak) | Pittsburg/Bay Point BART | No |
| 201X | Concord BART | Pittsburg/Bay Point BART | No |
| 202X | Brentwood Park & Ride | Brentwood Park & Ride | No |
| 300X | Antioch BART | Brentwood Park & Ride | No |
| 379 | Antioch BART | Antioch Medical Center | No |
| 380 | Pittsburg/Bay Point BART | Antioch BART | Yes |
| 381 | Pittsburg Marina | Los Medanos College | Yes |
| 383 | Wilbur and Cavallo Rd | Blue Goose Park | No |
| 384 | Antioch BART | Brentwood Park & Ride | No |
| 385 | Antioch BART | Brentwood Park & Ride | No |
| 387 | Pittsburg/Bay Point BART | Antioch BART | No |
| 388 | Pittsburg/Bay Point BART | Antioch Medical Center | Yes |
| 389 | Pittsburg/Bay Point BART | Pittsburg/Bay Point BART | Yes |
| 390 | Pittsburg/Bay Point BART | Antioch BART | No |
| 391 | Pittsburg Center BART | Brentwood Park & Ride | Yes |
| 395 | Antioch BART | The Streets of Brentwood | Yes (no weekdays) |
Discontinued Tri Delta Transit bus routes :
| Route | Westbound Terminal | Eastbound Terminal | Weekend service |
| 70 | 3rd & Marina | 3rd & Marina | No |
| 200 | Martinez station (Amtrak) | Wilbur & Cavallo Rd | No |
| 392 | Pittsburg/Bay Point BART | Brentwood Park & Ride | Yes (no weekdays) |
| 393 | Mariners Cove Dr & Pacifica Ave | Hillcrest Park & Ride | Yes (no weekdays) |
| 709 | Pittsburg/Bay Point BART | Antioch BART | No |
| Delta Express | Hillcrest Park & Ride | Lawrence Livermore National Laboratory | No |

#### Notes

* ↑ Operates loop service via Los Medanos College Brentwood Center
* ↑ Designed for traditional commute, operating westbound in the mornings and eastbound in the afternoons
* ↑ Operates during school days for Antioch Unified School District
* 1 2 Tri Delta Transit headquarters
* ↑ Operates loop service around via Bay Point
* ↑ Operates during commute hours
* 1 2 3 Operates exclusively on weekends and holidays, no weekday service
* ↑ Operates loop service in Pittsburg via Buchanan and Harbor
* ↑ "Early Bird Express" operated as a westbound-only route by Tri Delta Transit before regular weekday eBART service starts at 5 a.m.; eliminated starting from June 10, 2024.