Roundabouts

Roundabouts are proven to be a safer and more efficient intersection type over traditional signalized intersections and are being built more frequently in North America.

Frequently Asked Questions

Why are roundabouts being built and considered in Red Deer?

Feasibility studies for roundabouts in Red Deer confirm that:

  • With a growing population, modern roundabouts better service the traffic volume needs.
  • Serious and fatal collisions will be reduced by up to 80 per cent compared to a signalized intersection.
  • Traffic flow will improve and there will be reduced delays as drivers yield rather than stop at a red light. This also reduces vehicle noise and fuel emissions.
  • Modern roundabouts are statistically safer for pedestrians than signalized intersections because traffic speeds are lower and the crossing distances are shorter.
  • More uniform speeds with less starting and stopping reduce idling, fuel consumption and emissions.
Are roundabouts and traffic circles the same?

No, there are several differences between modern roundabouts and traffic circles, notably their size and how they operate. The modern roundabouts at 67 Street / 30 Avenue and 67 Street / Orr Drive, are approximately 60-65m in diameter. Traffic circles are generally larger than roundabouts. For example, the traffic circle at 107 Avenue / 142 Street in Edmonton is approximately 100m in diameter. Larger traffic circles operate differently than roundabouts. In traffic circles, drivers merge beside circulating traffic, which means that drivers circulating in the inside lane need to look over their right shoulder to make sure no one is beside them before exiting. In roundabouts, entering drivers yield to circulating traffic rather than merge beside circulating traffic. This eliminates a conflict point when exiting and makes them safer and easier to drive than traffic circles.

Are roundabouts safer than signalized intersections?

Yes, roundabouts provide enhanced safety benefits for motorists, pedestrians and cyclists versus a signalized intersection. The National Cooperative Highway Research Program reported a 35 per cent reduction in total crashes and a 76 per cent reduction in injury crashes after 55 intersections were converted to roundabouts. Injury crashes are lower at roundabouts than signalized intersections due to lower speeds, fewer conflicts between vehicles (and between vehicles and pedestrians) and the elimination of right-angle (T-bone) crashes.

Roundabouts are statistically safer for pedestrians than signalized intersections because traffic speeds are lower (giving pedestrians and drivers more time to judge gaps and react to each other and making any crashes that do happen less severe). The crossing distance is also less and pedestrians only have to watch for traffic in coming from one direction. This also makes drivers more likely to be looking in the direction of pedestrians (instead of up at the signals or left while turning right).

Does traffic flow better through a roundabout?

Yes, for the same number of lanes, roundabouts provide more traffic capacity than signalized intersections.

Roundabouts are able to accommodate higher traffic volumes, have fewer and shorter vehicle queues. This is because there is no “lost time” in the few seconds when all traffic has a red signal (the all-red interval), and because roundabouts are responsive to traffic demand. With roundabouts you never have to wait at a red light when no one is coming the other way.

What about large trucks in a roundabout?

Roundabouts on truck routes, such as high-wide corridors are designed with chevron markings through the entries to allow tractor semi-trailers to stay in-lane while entering the roundabout. Truck aprons are used around the central island at roundabouts as an overrun area for large trucks. This keeps the roundabout size reasonable and speeds low for other vehicles. Truck aprons were constructed around the central island as an overrun area for large trucks. Roundabouts are smaller than traffic circles and the smaller entry points and diameter encourages lower speeds through design. These truck accommodations ensure that large commercial vehicles can safely navigate the roundabout, while maintaining the natural speed control features achieved by a roundabout with a small diameter. A larger roundabout diameter would result in higher vehicle speeds.

How will Red Deerians know how to use a roundabout?

To learn about navigating the roundabout check out roundabout.how. This site covers all aspects of navigating a roundabout for all road users. Public input in early 2015 helped to shape the campaign and resident feedback was used to ensure concerns were addressed in the educational materials. Nine videos are being produced. The first (a basic overview) was released when the roundabout at 67 Street / 30 Avenue partially opened on October 30, 2015. The other eight videos cover the following:

  • Approaching a roundabout
  • Choosing your lane and signalling
  • Yielding and entering a roundabout
  • Signalling and exiting a roundabout
  • Signage
  • Pedestrians and cyclists (how to navigate if you are a pedestrian or cyclist and how motorists yield)
  • Large vehicles (how to drive a large vehicle through a roundabout, and what other motorists should do)
  • Emergency vehicles (how to yield)
Do other places build roundabouts?

Yes, roundabouts are common across North America, Europe and Australia. Roundabouts were first built in North America in the early 1990s, starting in the southwest of the United States of America. In 2008, the Federal Highway Administration identified roundabouts as a preferred alternative to signalized intersections when considering safety and operational benefits. After this, more roundabouts were and are being built across the continent. Roundabouts have been built in the United Kingdom since the 1970s, and in France and Australia since the 1980s. The USA has approximately 4,000 roundabouts; Canada has approximately 300 roundabouts (not considering small ones in residential areas) and; Australia has more than 9,000 roundabouts (with a population two-thirds that of Canada).