A scheme to link Cambridge with Huntingdon using guided buses is to be investigated by a government inspector.
A public inquiry has been confirmed for late September to look into the transport system which will be one of the largest of its kind in Europe.
The system is expected to cost about £80m and will be able to carry thousands of passengers along a 12-mile route.
The independent public inquiry will allow groups for and against the transport link to argue their views.
Cambridgeshire County Council welcomed the decision to hold an inquiry.
Shona Johnstone, cabinet member for environment and transport, said: "The fact that the inquiry is set for later this year means that this much needed scheme is still on track to be delivered in 2007."
The buses would run along a guide way using the former St Ives to Cambridge rail line for the majority of the route.