At the moment it is possible to cycle from Cambridge Road, near Madingley, to Girton, on a bridleway that crosses over the A428 and then passes under the M11 at the Girton Interchange. You can then cross three roads (A1307) and reach a pavement on the North-East side of the Interchange. Using the pavement you can then reach Washpit Lane and cycle up towards Girton. (The pavement is marked as a shared-use route on the OSM Cycle map, although I am not sure that it really is.)
Apart from having to be careful when crossing the A1307 junction it is a rather pleasant route to ride.
The Girton Interchange is being "improved" to reduce the bottleneck for cars. Does anyone know what plans there are to ensure that the current route through remains open and whether there are plans to improve the bridleway route through? Or will this be another example of roads being developed to the detriment of footpaths/bridleways.