A park and sleep business provides people a safe place to park and sleep in their vehicles while travelling long distances like a truck stop for cars. This is part of the cheap accommodation business and the cheapest option of all. It is a needed service in a country where a hotel room cost a months salary for some and the cost of living is spiraling out of control.
In a civilised country there are numerous places where you can get a well-needed rest while on a long car ride. This includes rest stops, truck stops, casino parking lots, supermarket parking, religious buildings. police stations etc. where you will find a safe, quiet, and free of charge place to park your vehicle and rest for the night. In South Africa – a world leader in violent crime it is unlikely that you will get such a service without paying for it.
How does this service look like?
Pick a national route (N1 to N18) find a piece of land just off it, maybe a hectare or so, fence it off, put a security there and let people park. That is it on the most basic level I would keep things really simple with portable toilets the only thing I would include, you could offer shower facilities but I would just fence off a piece of land. I would look for an area close to a major town. I stick to things I am familiar with, so I would go for N1, N7 (Cape-Namibia) and the N2.
The AA reckons you must not drive for more than two hours in one day while others say that you should take a break for 15 minutes every two hours. In South Africa this cannot be stuck to due to safety concerns, the short stops are a matter of finding a petrol station in a safe town. If you cannot find one you will drive till you find one.
Besides choosing a major route to straddle you need to choose a strategic town that gets a lot of passing traffic.
As someone that has driven the N1 Durban – Cape Town route with one driver, I would look at some notable stops and less notable, it obviously depends whether there are more than one driver and where the last stops were and how comfortable the driver is driving long distances. I remember major stops being Bethlehem, Winburg (driver got tired here), Bloemfontein, Beaufort West. It is impossible to predict where people are coming from and where they are going but there are usually major stops on a route. Like if you Capetonian and you driving from a another province and you reach Beaufort West you know you no longer in a ANC basket case province.