Roundabout configuration questions answered

BC Highways version will probably require that a truck apron be used if large trucks turn to/from the north-south road

Some local residents are opposed to the roundabout proposed for the corner of Highway 5 and the road to Wells Gray Park.

Others, who otherwise support the roundabout, have questioned the proposed design, which has two lanes running east-west for the highway but only one lane running north-south.

An animation found by reader Sharon Chaytor from Ourston Roundabout Engineering shows a similar two-lane/one-lane roundabout. The animation shows a variety of vehicles and pedestrians, including large trucks, negotiating the roundabout without apparent difficulty.

One possible important difference between the animation and the roundabout proposed for Highway 5 might be lane widths.

The single lanes in the animation appear to be at least half again as wide as each of the double lanes, while in a graphic from BC Highways of the local proposal they appear to be the same width.

According to Phillip Weber, principal project manager with Ourston Roundabout Engineering, “The original design our animation is based upon has wider circulating lanes north-south so that large trucks wouldn’t need to use a mountable truck apron around the central island.”

“The BC Highways version will probably require that a truck apron be used if large trucks turn to/from the north-south road,” Weber said. “On the other hand the BC Highways version may result in a more compact roundabout footprint. So there are pros and cons, and the best choice will depend on site context and other issues.”

Weber asked to see the highways department’s graphic but no further comments were received by press-time.

Ourston Roundabout Engineering describes itself as North America’s pre-eminent roundabout design team, with experience dating back to 1990.

 

The engineering company’s animation is available at www.ourston.com/resources/educational-tools/animations/four-leg.html.