Express bus service
On December 13, 2015, service to Contra Costa County on Route 42 was merged with Route 40. The next day, service began on Route 580, which was the District's first transit line into nearby Alameda County. The latter experiment failed and Route 580 was discontinued in September 2016. GGT buses returned to Alameda County in February 2019 to provide Early Bird Express bus service under contract with BART.