Hills Road south of the railway is to be resurfaced in sections over several weeks starting Monday 12 August. During that time, there will only be a northbound (towards the city) traffic lane open. The cycleway on the west side is not affected, but while the northernmost section is done there won't be any way to get to it from the Cherry Hinton Road junction, as it only starts after Purbeck Road. The road will reopen at 3.30pm each day, so evening rush-hour isn't affected.
So Monday to Wednesday and maybe Thursday morning on the week of the 12th you won't be able to cycle towards Addenbrookes from Cherry Hinton Road. You could walk that bit, or use Rock Road and the side streets east of Hills Road instead.