The six week programme was due to end on 10 October but due to exceptionally dry weather conditions, which has allowed the work to be undertaken more quickly than expected, the scheme will finish at 6pm this Friday, 3 October.
The A303 continues to operate as normal but the A37 eastbound entry and exit slips will be closed until Friday.
A fully signed diversion route will be in place advising driver wishing to join the A303 eastbound from the A37 to join the A303 westbound to Cartgate Roundabout, then turn around and continue along the A303 eastbound.
Traffic wishing to exit from the A303 eastbound carriageway on to the A37 will be diverted to continue along the eastbound carriageway to Podimore Roundabout, then turn around and travel back down the westbound carriageway to the A37 exit slip road.
Pedestrians will be able to cross the bridge throughout the works.
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.