Arriva introduces 11 gas-engine buses in Darlington March 26, 2013 | Europe News Arriva has introduced 11 gas-engine buses in Darlington after securing GBP2.2 million from the government's Green Bus Fund. The buses run on bio-methane, serving three routes in Darlington, the 2, 11 ... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password