The new junction will allow buses travelling on the busway to cross the road into College safely. The work is being carried by contractor Edmund Nuttall.
The planned busway will provide transport from St Ives to Cambridge with most of the 15.5 mile route along a disused railway line.
Chris Lang, vice-principal, director of finance and resources at Cambridge Regional College said: “Obviously there is going to be some disruption for people travelling to and from the college during the road works but we believe the short term pain is far out weighed by the long term gain for staff and students.”
The work will be done in stages is due to be completed in Spring 2008.