Motorists were caught up in significant delays in the Broadbridge Heath area as works continued on a scheme to downgrade the bypass.
Traffic was reported to be queueing on the A24 southbound slip road leading to the Farthings Hill roundabout.
The carriageway was reduced to one lane as works forge ahead to downgrade the A281 and create new cycleways and pedestrian access in the area.
One motorist said there were currently queues of vehicles as far back as the new Wickhurst Lane roundabouts. The AA also reported significant queues and disruption in the area.
West Sussex County Council said contractors were monitoring the disruption and removed traffic management to combat the delays.
A spokesman said: “Our contractors monitor traffic levels carefully. Just after lunchtime, they took positive action, removing the traffic management to ease the flow of vehicles when levels were noticeably higher than on previous days. We cannot be sure what caused this but it could be people had finished work early on the Friday of the school half-term holidays.
“When needed, we will take this sort of positive action and remove traffic management, provided it is safe to do so.”
For more on the works see our previous stories: Broadbridge Heath bypass works: All you need to know