The A41 will be closed for seven nights this week from 8pm to 5am.
The bypass will be closed in sections starting from Tuesday night (July 21) from the London Road, Bourne End junction to the Chesham Road, Berkhamsted turn off.
On Wednesday night the road will be closed from the Hemel Hempstead junction to the M25 roundabout. It will then be shut in the opposite direction the following night (Thursday).
On Friday (July 24) the busy road will be closed again from the Bourne End junction to the Berkhamsted turn off.
Then on Monday, July 27, the bypass will be closed between the Chesham Road, Berkhamsted junction and the Tring turn off.
The closures are to allow works to be carried out to underground traffic signal cabling.
Diversion routes will be in place for motorists.