Roundabouts cheaper, safer according to studies

Troublesome intersections can be made safer and for less money than traditional intersections according to studies performed by Transport Canada and the U.S. Department of Transportation.

New Brunswick cities are slowly including more roundabouts in their plans as a solution to such intersections.

Roundabouts are cheaper to operate since they don't require the installation, maintenance and operation of signal lights and are often cheaper to pave, according to a study published on the U.S. DOT website.

Not only are roundabouts cheaper but studies support the idea that the traffic control measures are safer.   

Studies show that when there is a crash within a traffic circle, it's usually a fender bender — not an accident that can cause serious injury.

City of Fredericton engineer, Darren Charters, said intersections allow for a greater opportunity for collision since there are more potential conflict points.   

Charters describes conflict points as the number of chances for a car to hit another car, or a pedestrian.   

He points out there are many more conflict points in a standard intersection, compared to a roundabout.

"It's 32 in this case versus 8 in a single roundabout," said Charters. "That would be higher with a two lane roundabout, but still — if you do come into contact with another vehicle you're going slow, and it's a side-swipe collision, it's not a T-bone injury collision most often."

Chance of serious injury decreases

Numbers from Transportation Canada support this idea.   

One 2000 study by the Insurance Institute for Highway Safety, looked at 24 intersections in the U.S. Ones that had changed over from stop signs or traffic lights, to roundabouts.   

The study found roundabouts reduced the overall number of collisions by 35 per cent, the number of injuries from collisions by 76 per cent, and the number of fatalities by 90 per cent.

The numbers found in the study are consistent with larger studies done around the world, according to Transport Canada.

Charters said if there is a minor accident, the city's roundabouts have an interior apron so that traffic can go around. 

Fredericton has set aside a piece of land for that purpose when it develops it's newest roundabout which will take motorists across busy Highway 8. 

"That's the biggest concern, getting folks to slow down," said Charters. "The key of a roundabout is the slow entry speeds, that makes them much more safe. So we're looking at dropping operating speeds from the 90 km/h range down to the 40 to 50 km/h range."

Ourston Roundabout Engineering , a national company that designs roundabouts, states two-lane roundabouts are not practical for more than 4,000 vehicles per hour.

About $500,000 has been allocated for a major traffic study to see how the Highway 8 roundabout will change traffic flow throughout the city.

According to the same site that published the report on accident reduction, a study performed at a Lincoln, Nebraska roundabout found that there was an increase in non-fatal collisions. Though researchers said that's common in the first few years, until drivers figure out how to use traffic circles properly.