The second route in Bristol's £230m Metrobus scheme begins operating today.
Passengers can now use the m2 service, which travels between the Long Ashton park-and-ride and Temple Meads railway station.
Metrobus said the m2 had replaced the 903 service and would "provide fast and frequent connections".
Due to open in 2017, it was delayed due to ticketing system issues, and it later emerged buses did not fit some guided sections of the route.
Remedial work to the 2.5km (1.5 mile) route cost about £200,000.
The affected route had been earmarked as the first of the three Metrobus routes to open.
Instead it was the m3 service between Emersons Green and the city centre which started operation on 29 May, run by Bristol Community Transport.
First Bus recently revealed that more than 120,000 passengers travelled on the m3 in its first two months in action.
The m1 route, from Hengrove to Cribbs Causeway, will begin operating in January.
The three bus routes have been billed as "the first buy-before-you-board service outside London" and link North Somerset, Bristol city centre and South Gloucestershire.