If the rule of thumb would be to not stop at a red light (in South Africa), traffic lights would be pointless.
if there is a rule of thumb in relation to this, it's that if you are driving and you feel threatened, if running a red light will diminish the threat, it's reasonably OK to run a red light.
I lived (and drove) in Johannesburg for about 2.5 years, and the above reasonably sums up the general consensus among South Africans.
I never ran a red light, seldom heard about others doing it and never heard about anyone being fined for it.
However, if you run a red light during rush hour in Sandton (a suburb of Johannesburg), the cops are likely to go after you if they notice.
Be aware of your surroundings at all times, and keep valuables out of sight.
Much more common than carjackings are smash-and-grabs: someone throws a brick through your car window and grabs valuables in sight, running off with them.
Also, at all times, at least make it appear as if you know what you're doing.
As important, it tends to be risky to not cooperate when a carjacking does happen.
But, that said, I've been told plenty of stories (and was in one myself) where the 'victim' pointedly did not cooperate, was not robbed and nothing happened.
Whether also the safest course of action is, of course, debatable.
travel.stackexchange.com/users/2271/MastaBaba
Disclaimer:
I have never driven in South Africa.
This BBC article says that half of all South African carjackings occur in Gauteng, and elliptically suggests that local drivers will disregard stop signs and stop lights in this province to avoid becoming a victim to the practise.
Carjacking is a category of danger that would be novel to most visitors from western Europe.
There are junctions which are signposted as carjacking blackspots, and there are areas where drivers will avoid stopping at red lights, particularly at night, preferring the risk of a fine to the risk of hijack.
"Many people may come in rented cars and then like everyone else they will run the risk of this," says Dr Burger.
He notes that "most of the time" carjacking victims are "threatened or violently removed... not seriously injured".
Unlike most categories of violent crime, recorded instances of carjacking are on the rise in South Africa.
The police do their best to fight it, says Pretoria News crime reporter Graeme Hosken.
"We have had a problem with gangs following tourists from OR Tambo airport [near Johannesburg] and the cops cracked down on that.
I take precautions.
I've been nearly hijacked myself on an open freeway."
He advises: Keep your car locked while driving Don't stop for strangers or people who have broken down A blue light does not necessarily mean they are police
If carjacked, do not offer resistance Carjacking is geographically skewed with half of the 15,000 happening in Gauteng http://news.bbc.co.uk/1/hi/8668615.stm
Of course the obvious strategy is not to drive at night in unsafe, unfamiliar areas, keep your doors locked and your windows up at all times.
However, in most of South Africa and especially in the day time, the consensus appears that you should treat traffic signs with appropriate respect and stop at red lights.
As Mark Mayo suggests in a comment, you could be fined if not.
The following advice comes from the UK foreign office.
Drive cautiously, obey speed limits and avoid unfamiliar rural areas at night.
Thieves have been known to employ various methods to make a vehicle stop (eg placing large stones in the middle of the road) enabling them to rob the occupants.
Park in well-lit areas.
Don’t pick up strangers or stop to help apparently distressed motorists, as this is a technique sometimes used by hijackers.
It’s better to report any incident to the police.
https://www.gov.uk/foreign-travel-advice/south-africa/safety-and-security
The other famous strategy is to install a "blaster" (a set of door-mounted flamethrowers designed to blind would-be assailants) on your vehicle, but I doubt you will obtain a rental car with this feature.
http://edition.cnn.com/WORLD/africa/9812/11/flame.thrower.car/
travel.stackexchange.com/users/29377/Calchas
I was born in Johannesburg, and lived in South Africa for 22 years.
I drove my self around since I was 18.
I have spent time in all the major cities and driven the Johannesburg-Cape Town road (~1500 km) at least 10 times.
From my experience, you certainly should stop for red traffic lights and generally obey all rules of the road.
The only possible exception would be in rurual / unsafe areas, late at night.
However, I would strongly recommend avoiding that situation.
Stay in built up, "tourist" areas, particularly late at night.
If you are unsure, ask your accommodation, they will be happy to advise.
travel.stackexchange.com/users/31003/JP Janet
I have family and friends in Pretoria and Johannesburg, and they all stop at a red lights.
But this is my opinion
travel.stackexchange.com/users/31535/simbad
Yes ofcourse, we do stop when the traffic signal shows red light as it clearly means to Stop.
I have relatives staying at South Africa and I have never heard of them saying they do not stop at red light of traffic signal.
But yes,different countries have different traffic rules so it would be better if you would hire a driver for your own safety.
travel.stackexchange.com/users/31536/Ramaya
If it is true, are there any rules of thumb about where you should and shouldn't do it.
Is it true you must not stop at Red lights in South Africa while driving?
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<legal><driving><south-africa>
travel.stackexchange.com/questions/50769
travel.stackexchange.com/users/60/Dan
Generally speaking, people follow the rules of the road in South Africa and stop at traffic lights. However, there are junctions which are signposted as carjacking blackspots, and there are areas where drivers will avoid stopping at red lights, particularly at night, preferring the risk of a fine to the risk of hijack. If you feel threatened and think that running a red light will diminish this threat, it may be reasonably acceptable to do this.  Although carjacking is a problem in South Africa, it is not normally a reason to run a red light. In general, it is recommended to follow the rules of the road and stop at stop signs, especially during daylight hours. The risk of carjacking is higher at night and in carjacking blackspots. It is recommended to avoid those areas of possible. Running a red light carries the risk of a fine.
It is normal to stop at red lights in Johannesburg and most residents do that. This is especially true during daylight hours. In fact, drivers may be fined for running red lights. It is only recommended to run a red light when the driver feels threatened. There are some areas that are carjacking blackspots and it would be better to avoid them if possible.