Three people have died and three others were seriously injured in a crash on the R60 between Ashton and Robertson in the Boland on Friday morning.
Western Cape traffic authorities confirmed that emergency services were dispatched to the scene, where rescue and recovery operations are ongoing.
Western Cape traffic chief Maxine Bezuidenhout said the R60 has been closed to traffic while authorities clear the scene and investigate the cause of the collision.
"The R60 remains closed while recovery operations and the necessary investigations continue," Bezuidenhout said.
Motorists travelling between Robertson and Ashton have been urged to make use of alternative routes until the road is reopened.
Traffic officials have advised drivers to travel via the R317 through Bonnievale to reconnect with the R60, or to use the R62 through Montagu, depending on their destination.
Authorities have also urged motorists to follow the instructions of traffic officials on the scene, expect delays, and exercise caution while travelling in the area.
"We urge all road users to reduce their speed, remain patient, and exercise caution while travelling in the area," Bezuidenhout said.
The circumstances surrounding the crash are under investigation.