The N2 in Plettenberg Bay remained closed on Wednesday morning following overnight protests.
In a Bitou Municipality notice, motorists were warned that the highway was closed between the Shell Ultra City and Kwanokuthulu due to the ongoing community protests that started in Qolweni on Tuesday night.
A group had begun throwing stones and burning tyres to block the road.
Last month, residents had marched from Qolweni to the municipal buildings over service delivery.
Organisers of the march said they were disgruntled by high unemployment rates, the slow pace of housing projects, people who rented their houses and stayed in shacks, tenders awarded to the same businesses and a lack of progress in sport development in their community.
The municipality said on Wednesday that various authorities were on the scene. These included the public order police, crowd management officials and provincial traffic.
"Traffic in both directions [is] still being diverted via the airport/Robberg Road from the Knysna direction and through Plettenberg Bay town, from the Port Elizabeth direction," the municipality said in a statement.