The Mi-Link 003 service, operated by First Bus, is carrying passengers in Oxfordshire between Didcot Parkway train station and Milton Park.
It follows trials of a self-driving mini-bus around Milton Park, which then expanded to a round trip between the station and the business park. here
The bus company's head of policy called it "revolutionary".
First Bus said the bus' radar, LiDAR and AI technology could safely steer, accelerate and brake without the need for human intervention.
It has a safety driver who is able to take over at any point and take full manual control if needed.
They are also on board to "provide a personalised service and information to passengers".
The full size bus began operating on Thursday 7th September and will run every 30 minutes from 07:00 to 18:30 Monday to Saturday until the trial's conclusion on 30 September.
Head of policy John Birtwistle said First Bus was "leading the way" and bringing an "innovative and green approach to the future of public transport".
|In June 2023 An autonomous bus service using a 15 seater Mellor Orion E bus was launched between Didcot Parkway train station and Milton Park.|
He added: "The next phase in this ground-breaking bus service gives us the opportunity to show more customers the exciting possibilities afforded by combining zero emission and digital autonomous technology to provide a smarter, cleaner and quieter way to travel."
According to the company, the previous trials clocked 3,000 miles and saved 1.5 tonnes of carbon.
Milton Park is a science, technology and business community in Oxfordshire, with more than 270 companies and 9,000 employees.
In May 2023 Stagecoach launched their 14 mile diesel powered autonomous bus service in Scotland, see here