Stagecoach East called for action on tackling congestion as it announced timetable and route changes brought about traffic issues.
Revealing changes to three services to take effect on 20 April, the operator cited congestion in and out of Cambridge for buses being unable to meet the current timetables.
The adjustments include minor timetable tweaks, a frequency update and a slightly shortened route on service A and B on the Cambridge Busway.
Ross Barton, Operations Director at Stagecoach East, said: “We only ever make changes to our timetables after considering every option, but the fact is that congestion in and out of Cambridge means that our buses just cannot meet the times set on existing timetables.
“We know what an important artery the Busway is for people needing to travel into Cambridge, so I would call on everyone concerned with our local roads to continue to work together to avoid delays.
“We live and operate in a dynamic, forward-looking city, and the Busway is an essential part of that, so we need to make sure that buses are able to get through.”
Stagecoach East has repeatedly called for the problem of bus speeds to be addressed, with Managing Director Darren Roe saying the issue will be a vital one to solve under the forthcoming move to franchising in Cambridgeshire.
Meanwhile, last week the operator announced an improved Sunday service on the Busway A route from St Ives Park and Ride to Cambridge City Centre. From 20 April, journeys will take place every 15 minutes rather than hourly, although this will replace some trips on service B.