Driving in a roundabout is easier than most people think. According to an Insurance Institute of Highway Safety (IIHS) study, even roundabout skeptics usually change their minds once they understand the rules for driving in a roundabout and discover benefits, such as less time spent waiting at intersections.
Roundabouts often are the first choice for new road construction and existing road expansions, thanks to their ability to handle higher traffic volumes and reduce crashes compared to traditional signal- or sign-controlled intersections. They even waste less fuel and are better for the environement (less emissions) since cars don’t back up and idle while they wait for their turn (as they would at a red light).
So why do so many people resist driving in roundabouts? Researchers say it’s often reluctance to change longstanding habits (“Stoplights have always worked fine for me!”). Modern roundabouts also get a bad rap from drivers who have suffered anxiety trying to navigate old-fashioned East Coast traffic circles or European rotaries with their higher speeds, multiple lanes and confusing traffic signals.
Drivers often lack confidence that fellow motorists know what they’re doing. A PEMCO Poll revealed that while 81% of drivers report being at least “very confident” that they know how to drive in a roundabout, that number drops to 21% for how they feel about other drivers’ knowledge.
In an IIHS study on the acceptance of new roundabouts, researchers found that before construction, 31% of drivers said they were in favor of a new roundabout while 41% said they were strongly opposed. After using them, though, the number of roundabout naysayers dropped to just 15%, with 63% of drivers saying they preferred the roundabout over a traditional intersection.
Yielding to traffic in a roundabout
Safely navigating roundabouts usually boils down to knowing how and when to yield:
- Slow down as soon as you see a sign warning you’re approaching a roundabout. That might be a yellow sign with a circular three-arrow symbol, a traditional red and white Yield sign or, for multilane roundabouts, white and black arrow signs showing which lane you’ll want to enter.
- Approach to enter the outside lane if you’ll be turning right or going straight on a multilane roundabout.
- Approach to enter the inside lane if you’ll be turning left or making a U-turn on a multilane roundabout. You also can go straight from the inside lane.
- Yield to pedestrians who may be crossing just before the roundabout or about to step out from the triangular island preceding your entrance.
- Yield behind the dashed line if a vehicle in the circle is approaching your entrance. That’s true even on multilane roundabouts if you’re planning to enter the outside lane and the approaching vehicle is on the inside lane.
- Enter the roundabout without yielding if no cars are approaching.
- Only travel counterclockwise in a roundabout.
- Don’t drive next to a truck or other oversize vehicle. In multilane roundabouts, they may need to take up both lanes to navigate turns or drive up onto the “truck apron” of the center island to accommodate their trailer.
- Keep your speed down. Plan for 15-20 mph in an urban roundabout and no more than 30-35 mph on wide, sparsely populated rural-road roundabouts. Continue in your lane until you reach your exit.
- Turn on your right turn signal before exiting to alert other drivers so they won’t enter your exit path. If you’re exiting from the inside lane and an approaching outside lane car potentially could cross your exit path, turn off your signal, stay in your lane and take another circle. Complete your exit when the outside lane is clear and it’s safe to cross.
- Once in the roundabout, don’t change lanes or back up. If you miss your exit or another driver is in your exit path, just continue around and try again.
- Never stop in the roundabout except to avoid a collision.
RELATED: Roundabouts | WSDOT (wa.gov)
How roundabouts make driving safer
Studies by IIHS and the Federal Highway Administration show that, compared to traditional signal- or sign-controlled intersections, roundabouts reduce collisions by:
- 90% for fatalities
- 75% for injuries
- 40% for pedestrians and
- 37% overall.
Their one-way-only traffic, speed-reducing circular lanes and the barrier of a center island combine to make the difference. Even if a collision does occur, low speeds reduce the potential for serious injuries and damage. The center island keeps drivers separated as they move around the circle in the same direction and, without a light, there’s no incentive to speed up to “beat the light” or the possibility of running a red light. The continuous flow of traffic in the same direction minimizes the chance of head-on or T-bone collisions, the most dangerous types of crashes.
Multilane roundabouts are tougher for drivers and pedestrians to use than single-lane roundabouts. They tend to have smaller reductions in crash rates or even temporary increases in less-serious crashes until drivers became familiar with them, according to IIHS. For single-lane roundabouts, entering is the most dangerous time. For multilane roundabouts, exiting is the most dangerous time.
Rear-end, sideswipe and run-off-the-road accidents are the most common collisions in roundabouts. Almost half of the run-off-the-road accidents involve drivers hitting the center island when they didn’t see the roundabout in time to slow down before entering it.
Roundabouts save drivers time and money
The Federal Highway Administration estimates that, compared to traditional intersections, roundabouts increase traffic capacity up to 50%. In a separate study by IIHS, roundabouts cut delays by 89% and, since cars only need to yield to enter the roundabout rather than waiting for a light to change at an intersection, reduced stops by 56%.
IIHS researchers extrapolated the data to conclude 23-34% less fuel is burned at a roundabout-controlled intersection versus a sign- or signal-controlled intersection. Without all that idling waiting for the light to change, emissions at intersections drop, too, including environmental polluters like carbon monoxide (reduced 15-45%) and carbon dioxide (reduced by 23-34%).
Why some intersections get roundabouts and others don’t
Not all intersections make good candidates for roundabouts, even as some drivers lobby for them. Sometimes, there’s simply not enough space, since roundabouts require more room than a traditional intersection. Engineers also favor roundabouts for intersections where the traffic is pretty balanced from all sides; less so where a heavily traveled main road intersects with lightly used side roads.
When it comes to funding, high-crash intersections often get priority for roundabout construction. Initial costs can be higher if adjoining land needs to be purchased to accommodate the roundabout; however, over time, roundabouts are cheaper to maintain than signal-controlled intersections with traffic lights that require servicing.
Remember that whether trouble finds you in a roundabout, on the open road or even in a parking lot, CPW is here to help!