Motorists will face severe delays today and tomorrow due to roadworks on Allum Lane.
Temporary traffic lights on Allum Lane, between the bridge and Deacons Hill Road, are causing severe delays.
Vehicles are queueing along Shenley Road as they try to travel along Allum Lane, where drainage works are being carried out.
A number of bus routes have also been affected by the roadworks.
Works are scheduled to take place today and tomorrow and are being carried out by Hertfordshire County Council contractor Ringway.