An ambulance was called on Friday afternoon to a stretch between Hatters Wat and Skimpot, and passengers were forced to disembark, according to an eyewitness.
The eyewitness said: “A bus ended on the wrong side of the busway causing oncoming buses to stop and all passengers disembarking and walking along the footpath by the busway. My husband and myself witnessed the incident scene a few minutes after it as we went for a walk down the Busway footpath.
"We saw the paramedic looking after the passenger and the bus driver head bent forward in the driving seat but ok. We also saw all the passengers walking away from the buses.
"There were also what appeared to be a few bus drivers and bus company investigator staff. When we finished our walk and headed back that way there was five buses stuck in the queue, empty of passengers and bus drivers and the incident bus. The ambulance was just leaving but no siren.
"There was also a breakdown truck. There are wheel scuff marks on both sides of the concrete busway showing the possible cause of lane change for the incident bus.
She added after going for a walk along the route on Sunday they saw ‘slow down’ signs had been added to the busway.
A spokesman for Arriva said: “I can confirm there was an incident involving one of our buses, on the Luton Bus Way – this is being investigated by the depot, so we can understand the cause”