Alan Winde says the N1 highway near Worcester in the Boland has been closed until further notice due to severe weather conditions affecting the region.
Winde urged motorists to make use of alternative routes, warning that the closure will significantly affect travel to and from Cape Town.
He added that several mountain passes along the escarpment have also been shut down as heavy rain, flooding and gale-force winds continue across parts of the province.
According to Winde, motorists travelling north are being redirected via alternative routes, including through Victoria West along the R63 and R67, and through Loxton, Fraserburg, Williston, Calvinia, Nieuwoudtville and Vanrhynsdorp before reconnecting with the N7.
Additional diversion routes include roads near Beaufort West and Leeu Gamka.
Winde cautioned motorists using the R318 route via Montagu and Ashton that the road is narrow and lacks shoulders despite being tarred.
Meanwhile, the City of Cape Town Disaster Risk Management Centre says clean-up and emergency response operations are continuing across affected areas.
Disaster Risk Management spokesperson Charlotte Powell said assessments of damage in informal settlements are ongoing as authorities respond to the widespread destruction caused by the storm.
“Teams are attending to service faults, although some repairs have been delayed because conditions remain unsafe for staff due to the strong winds,” Powell said.
She added that assessments in informal settlements are continuing and that non-governmental organisations have been activated to provide immediate relief where assessments have been completed.
“The impact of the frontal systems has been extensive, and teams are working as quickly as possible to respond,” she said.