roundabouts faq

Question: What is a roundabout?

Answer: A roundabout is an alternative form of intersection traffic control. A modern roundabout is a circular intersection with yield at entry. It promotes safe and efficient traffic flow. They were introduced in the U.K., but are gaining more widespread use in North America, with implementation in many U.S. states and several Canadian provinces. Typical characteristics of a modern roundabout include: Yield at Entry One-Way Travel around the central island (counterclockwise) Slower Speeds Roundabouts have the potential to reduce collisions, traffic delays and fuel consumption resulting in improved air quality through reduced vehicle emissions.

Source: http://www.mto.gov.on.ca

Question: What is the difference between a roundabout and a "traffic circle"?

Answer: Modern roundabouts are generally much smaller than older traffic circles, and require vehicles to negotiate a sharper curve to enter. These differences make travel speeds in roundabouts much slower than speeds in traffic circles. Because of the higher speeds in traffic circles, many were equipped with traffic signals or stop signs to help reduce potential collisions. In addition, some traffic circles operated according to the traditional yield-to-the-right rule, with circulating traffic yielding to entering traffic.

Source: http://www.mto.gov.on.ca

Question: How do roundabouts affect traffic flow?

Answer: Because approaching traffic only has to yield to vehicles already circulating in a roundabout, movement is often without delay. It has been shown that a roundabout can move traffic through an intersection at a much higher rate than traditional intersection controls.

Source: http://www.mto.gov.on.ca

Question: Are roundabouts safe for cyclists?

Answer: The way cyclists operate through a roundabout depends on their degree of comfort and experience level with riding in traffic. More experienced cyclists may choose to circulate as a vehicle, merging into the travel lane before the bike lane or shoulder ends. Less experienced cyclists can dismount their bicycles and use the roundabout like a pedestrian would.

Source: http://www.mto.gov.on.ca

Question: Can older drivers adjust to roundabouts?

Answer: Relative to other age groups, senior drivers appear to be over-involved in crashes occurring at traditional intersections. Roundabouts eliminate a number of problem areas for older drivers that are typical of traditional intersections, such as left turns and entering busy thoroughfares from cross streets.

Source: http://www.mto.gov.on.ca

Question: When and where is a roundabout appropriate?

Answer: Roundabouts are appropriate for many intersections, including locations experiencing high numbers of collisons, long traffic delays, four or more approaches with relatively balanced traffic flows, and frequent left turn movements. They are an appropriate solution in both urban and rural settings, along busy arterial roadways, as well as at certain highway entrances and exits.

Source: http://www.mto.gov.on.ca

Question: Do roundabouts require more space than a traditional intersection?

Answer: Roundabouts can process traffic more efficiently than traffic signals and stop signs; therefore, typically requiring fewer traffic lanes to accommodate the same amount of traffic. Roundabouts do not necessarily require more space than traditional intersections; however, geometric design details vary from site to site and must take into account traffic volumes, land use topography, and other significant factors.

Source: http://www.mto.gov.on.ca

Question: Is the cost of constructing a roundabout more than a traditional intersection?

Answer: Modern roundabouts are sometimes less expensive than traffic signals, particularly in the long run. Generally, the initial construction cost of a roundabout is similar to the initial construction cost of a signal, but because there are no traffic signals, equipment maintenance costs are less. As well, because traffic moves through a roundabout in a very efficient manner, it is possible that streets between roundabouts can operate well with fewer lanes, providing a savings in associated construction costs.

Source: http://www.mto.gov.on.ca

Question: Are there special lighting requirements for roundabouts?

Answer: Guidance features like signs, pavement markings, and other physical elements (like splitter islands) require adequate nighttime illumination to avoid driver confusion and to increase pedestrian safety.

Source: http://www.mto.gov.on.ca

Question: Are roundabouts safe for the visually impaired?

Answer: People who are visually impaired may experience difficulty using roundabout crosswalks, particularly where traffic volumes are high. Roundabouts, like channelized turn lanes, present challenges different from other intersections since the traffic is most often under yield control as opposed to stop control. It is difficult to be sure that traffic will yield to pedestrians, and the continuous circulation of vehicles makes it difficult for the visually impaired to determine significant gaps in traffic movements. In addition to determining when to cross the road, pedestrians with vision impairment must identify where to cross, which way to walk during the crossing, and when they have arrived at their destination curb or island.

Source: http://www.mto.gov.on.ca