I understand that you must yield to a vehicle in a traffic circle. But what about when a line of vehicles enters the circle through one of the entry points without slowing down while other cars are waiting at the other entry points until this line pushes through? Is that allowed? This defeats the original purpose of the circle, which is to replace static four-way stops with a fluid yield-and-go system. – Darryl, Ottawa
There’s a circular logic to traffic circles, but plenty of drivers still get confused, experts say.
also known as roundabouts, they are circular intersections where drivers travel counterclockwise around a centre island.
They’re common in many countries worldwide but relatively new to most Canadian cities, which is why many drivers here don’t fully understand how they work, said Sean Shapiro, a road safety consultant and former Toronto traffic officer.
“It’s like playing chicken driving in them here,” he said.
When approaching a traffic circle, he said every driver is supposed to slow down, yield to traffic already in the circle (and any pedestrians who are crossing) and then, once there’s a gap in traffic, slowly go through.
“It should be really simple: When you approach that circle, if the way is clear [and] there’s no traffic coming you enter. And if there is a car coming, you wait until they pass you and then you enter,” Shapiro said.
He said drivers shouldn’t be following other cars into the circle without yielding – so there should never be a convoy of cars going through one entrance while everyone else waits at the other entrances.
If you do tag along as the car in front of you goes through the circle, you could face charges including failure to yield. In Ontario, it’s an $85 fine and three demerits.
The rules are similar across Canada.
“When entering a typical traffic circle, those in the circle have the right of way. This is easily identified by the fact that those entering the circle have a yield sign,” Corporal Troy Savinkoff, an Alberta RCMP spokesman, said in an e-mail. “Every car individually has to yield to oncoming traffic, so a ‘convoy’ of cars going through would be illegal.”
Rounding errors
Ottawa police said there were 280 collisions reported at traffic circles there in 2024 – 25 of the collisions led to charges.
When designed properly, traffic circles are “statistically safer” than standard intersections because drivers should be going slower, Shapiro said.
Also, drivers aren’t turning left in front of other vehicles – so you won’t see head-on or T-bone crashes.
Studies show changing an intersection to a traffic circle from one with a stop sign or traffic lights reduces injury-causing crashes by 72 to 80 per cent and reduces all crashes by 35 to 47 per cent, according to the American-based Insurance Institute for Highway Safety (IIHS).
But many drivers don’t slow down enough, if at all, before entering the circle. The top speed through the circle should be around 20 kilometres an hour, Shapiro said.
“You should be reducing your speed to a manageable safe speed that allows you to make decisions and minor adjustments to allow a vehicle to merge in (front of you) if need be,” Shapiro said.
If there’s more than one lane, make sure you’re in the lane that matches the exit you need – there are usually signs before the circle that show where the lanes exit, Ottawa police said.
Once you’re in the circle, you shouldn’t be changing lanes. You also shouldn’t be stopping or yielding for traffic that’s entering the circle – they should be yielding to you, Shapiro said.
Even if you have the legal right of way, you may have to stop or yield anyway to avoid a crash, Shapiro said.
“At the end of the day, it doesn’t matter whose turn it is because if the other person doesn’t agree with you, you’re going to end up in a collision,” he said. “The smart move is to have patience and do what is safe for you.”
If traffic is flowing properly, drivers shouldn’t have to stop at all, Shapiro said.
“It shouldn’t ever get so congested that people are stopping [before entering], but I can see how it happens depending on the size of the traffic circle,” he said. “If one person is unsure of what to do, they create this pause that could end up in five or 10 cars waiting.”
But he said drivers also shouldn’t feel pressure to enter a busy circle when they’re unsure what other cars are doing.
”In a situation where it’s unsafe for you to enter, wait until it is safe,” he said.
Then, when you’re ready to leave, use your right-turn signal at the exit so other drivers know you’re leaving.
“Signalling as you go into the roundabout is silly because there’s nowhere to go but in.”
Learning curve
If a traffic circle is so busy that traffic is regularly backed up, then maybe it’s not the right fit for that road, Shapiro said. Also, the design of the circle could cause problems.
According to guidelines from the U.S. Department of Transportation, depending on the road, traffic circles should be designed with curves sharp enough – and lanes narrow enough – to slow down traffic while still allowing bigger trucks through. The circle’s curve should make it impossible to barrel through without hitting your brakes.
Designers must also consider pedestrian safety. If crosswalks are too close to the circle, drivers exiting the circle may not see pedestrians crossing.
“If [drivers are] going too fast, they’re surprised by pedestrians,” Shapiro said, “As a pedestrian, be cautious – as much as we want cars to keep us safe, every time you cross a road you’re putting yourself at risk.”
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