Roundabouts

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Should London try some of these?
Is it true that “traffic lights are an unnecessary evil“?

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Can-Amera Parkway at Townline Road, City of Cambridge  

A roundabout or rotary is a type of road junction (or traffic calming device) at which traffic streams around a central island, after first yielding (giving way) to the circulating traffic. In the United States it is technically called a “modern roundabout“, to emphasize the distinction from the older, larger type of traffic circle. Roundabouts are statistically safer than both traffic circles and traditional intersections, though they do not cope as well with the traffic on motorways or similar fast roads.1

A modern roundabout is an unsignalized circular intersection engineered to maximize safety and minimize traffic delay. The intersection design accommodates traffic by a circular flow in a counter-clockwise direction around a central island.2

Roundabouts are safe, efficient and less costly than signalized intersections… Modern roundabouts follow the “yield-at-entry” rule in which approaching vehicles must wait for a gap in the circulating flow before entering the circle.3

Eliminates maintenance costs associated with traffic signals which amount to approximately $3,500 (US) per year per intersection. In addition, electricity costs are reduced with a savings of approximately $1,500 (US) per year per intersection.4

In many cases a roundabout can offer a safer environment for pedestrians than a traffic signal because the pedestrian crossing at a roundabout is reduced to two simple crossings of one-way traffic moving at slow speeds. A pedestrian crossing at a traffic signal still needs to contend with vehicles turning right or left on green, vehicles turning right on red and vehicles running the red light. The latter of these potential conflicts occur at high speeds and often result in injuries or fatalities to pedestrians.5

In “Kill dumb stoplights, let’s go roundabout” (Toronto Star; 2006/05/13), Jim Kenzie writes:
Traffic lights make precious little sense even in urban areas: the massive increase in side impacts caused by people running red lights shows that. And that’s just from a safety perspective. Stop-and-start driving is slower, wastes fuel and contributes to smog. How should we control traffic at intersections? The answer is obvious to anyone who has travelled beyond our little continent: roundabouts.”

The number of roundabouts constructed in Canada is relatively small. Those that are currently in operation have been reported to be performing favorably, when compared with conventional controlled intersections (i.e., stop signs or signals), in terms of improved safety, shorter delays, increased capacity, and improved aesthetics. Early results generally indicate that roundabouts have resulted in an overall reduction in the number and severity of accidents, despite the initial concern that lack of familiarity with this type of intersection would lead to driver confusion.6

sources:
1. Wikipedia
2. City of Yorkton, Saskatchewan
3. City of Saskatoon, Saskatchewan
4. Roundabouts USA
5. Roundabouts FAQ – City of Ottawa
6. Modern Roundabout Summary – Hamilton, Ontario
7. Ourston Roundabouts Canada
8. ICBC Roundabout Driving Tips

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