The Citi 2 provides a service into Cambridge and on to Addenbrooke's hospital. It used to run through Milton but no longer does so.
View Citi 2 - South in a larger map
The one exception is one late night bus which provides a service Monday to Saturday at 23:05 from Cambridge to Milton. See the service 9 page for more on this.
However the Citi 2 service is still worth mentioning as it runs as far as the Science Park, so if you need to get to somewhere the Citi serves it's possible to get a Park & Ride bus (a ticket from which counts as a Dayrider, but is cheaper) get off opposite the Science Park, walk across and get onto the next Citi 2 bus. Alternatively get a service 9 to the stop opposite the Golden Hind and change there.
The Citi 2 service runs from Monday to Saturday service from the Science Park through Chesterton via Green End Road and Chesterton High Street into the city centre at Emmanuel Street. It then continues to Addenbrooke's hospital via Mill Road and the ring road (with a short detour into the Birdwood Road estate). See box at the bottom for full route. The entire journey takes about 50 minutes end to end.
The return service follows basically the same route except it stops in St Andrews Street rather than Emmanuel Street.
You can find the full timetable on the County Council web site bus pages.
Citi 2 - Complete Route
From the Science Park into Milton Road, left into Green End Road, left again into Chesterton High Street through Chesterton, across Elizabeth Way and on down Chesterton Road, past Mitcham's corner and Jesus lock, left into Magdelene Street and over the river, left again into Round Church Street, right into into Park Street, left into Jesus Lane down to the roundabout, right into Emmanuel Street, right and left into the next part of Emmanuel Street, and left into St Andrew's Street.
Left into Park Terrace and then right down Parkside across the traffic lights into Mill Road. All the way down Mill Road to the end, right onto the ring road (called Perne Rd at the point), next left into Birdwood Road, right into Walpole Road, right into Cherry Hinton Road, then left into Wulfstan Way, right into Queen Edith's Way and from there straight to Addenbrooke's.
Return journey is basically the same except that from St Andrew's Road it goes up Hobson Street to get to Jesus Lane, rather than via Emmanuel Street.