Getting stuck in a roadblock is annoying, especially if you're on a schedule to get somewhere. But it's important to remember that the police carry out roadblocks for good reason – reasons we don't always think of in the moment. There are two kinds of roadblocks in South Africa that perform different functions. The biggest difference between these two is the police’s ability and right to search your vehicle and person.
Informal roadblocks: You'll usually find these on major roads and off-ramps. Their main goal is to stop drunk driving, speeding and check the roadworthiness of vehicles. They also usually check for outstanding fines. A search cannot be performed without a warrant unless the officer can prove extraordinary circumstances.
K78 roadblocks: These are more formal roadblocks approved by the National Police Commissioner. Police officers are allowed to search your vehicle and your person without a warrant. These roadblocks are usually set up to find a specific criminal or vehicle already on their radar.
Effective roadblocks are a good way to catch criminals, bust drug traffickers and get dangerous drivers off the road. For example, in May this year, Mbombela police arrested three men in possession of drugs with an estimated street value of R60m, and again at a roadblock held during the launch of Operation Easter Safety Campaign another package of heroin worth around R2.5m was confiscated (see source article at https://bit.ly/2N4tEUo). And there are similar stories from across South Africa of law enforcement getting the bad guys off our streets. So yes, it can be annoying to be held up at a roadblock, but ultimately they help keep us safe.