Can roundabouts solve Cape Town’s traffic nightmare?

Cape Town motorists fed up with daily congestion are questioning whether traffic lights are making things worse, but a traffic engineer says the answer depends on traffic volumes.

The debate comes as frustrated drivers point to intersections where broken traffic lights appear to improve traffic flow, with motorists treating them as four-way stops.

RELATED ARTICLES:

-- New traffic measures loom as Cape Town battles growing congestion

-- City of Cape Town’s Traffic Service records uptick in violations

A caller to CapeTalk raised the issue, saying some intersections flow better when the lights are out, as drivers take turns instead of trying to beat the robot.

But Stellenbosch University traffic engineer Dr Megan Bruwer said that only works under specific conditions.

“It’s a difficult question… sometimes it does actually work better, but there’s a very specific time that it will, and that’s when there are very low traffic volumes.”

She explained that four-way stops create gaps between vehicles, limiting how many cars can pass through an intersection per hour.

By contrast, traffic lights allow multiple vehicles to move at once.

“What we do is we tell a whole lot of people at the same time: you can all go together… and that’s why they are much more efficient when you’ve got high numbers of traffic.”

Why peak-hour traffic needs signals

Bruwer said traffic lights are essential when volumes are high or uneven.

This includes intersections where one direction carries more vehicles or where many drivers are turning right.

In those cases, signals help manage congestion and prevent bottlenecks.

Without them, traffic would quickly back up.

Roundabouts gaining attention

With ongoing issues like cable theft affecting traffic lights, some municipalities are converting signals into roundabouts.

Bruwer said roundabouts can handle higher volumes than four-way stops and help balance traffic flow, but, again, only in the right conditions.

“Roundabouts actually work a lot better than four-way stops in terms of the amount of volume that they can handle.”

Confusion in circles adds to frustration

Cape Town drivers’ struggles don’t end there.

Brewer pointed out that confusion between roundabouts and mini circles is adding to traffic chaos.

Roundabouts follow a ‘give way to the right’ rule, while mini circles operate more like a four-way stop: first-come, first-served.

That difference, she said, is likely why many motorists get it wrong.

For more information, listen to Bruwer on CapeTalk’s Good Morning Cape Town with Lester Kiewit using the audio player below: