City and transit officials are gathering Thursday to celebrate progress on BART's new diesel-powered service into eastern Contra Costa County.

The East Contra Costa BART Extension, or eBART, is a $525 million project that will run 10 miles along Highway 4 from the Pittsburg/Bay Point station to two eBART stations in Pittsburg and Antioch.

BART spokesman Taylor Huckaby said the Pittsburg/Bay Point station parking lot fills up "to the brim" every morning.

"There's a lot of people that are moving out into the East Bay, and we want to connect them to the central BART system," he said. "We want to be able to get people to their jobs and where they need to go."

The new service will use diesel multiple-unit trains, or DMUs, which are smaller and less expensive than BART's conventional trains. The agency says eBART is expected to be ready for commuters by May 2018 and will make the 10-mile trip from Antioch to Pittsburg/Bay Point in 10 minutes. Passengers will be able to transfer there to BART's main line to Oakland, San Francisco and SFO.