Roundabout near Edmonton designed for oversized vehicles

Alberta Transportation has started construction of a new roundabout northwest of Edmonton at the intersection of Highway 44 and Highway 633 east of Villeneuve.

The Edmonton office of CIMA+ (Dan Dmytryshyn, project manager) designed the new structure, which is configured to be able to handle oversized vehicles of the type typically used in the oil fields.

Roundabouts can be challenging to design because they must allow large vehicles a large radius to turn. In this case, so as not to make the area of the roundabout too large, the structure was designed with traversable splitter islands, so that oversize trucks can drive across the centre of the island if necessary. Signs at the roundabout are mounted on moveable bases, and traffic will need to be temporarily halted when an oversize vehicle crosses. Alberta Transportation says that such occurrences would be relatively infrequent and would be done during night-time or off-peak hours.

Alberta Transportation’s traffic modeling indicates that the current single lane roundabout will not be adequate in the long term, so the roundabout is being designed so that in future it can be converted to two lanes by reducing the size of the islands and the truck apron. The signage and lighting is also being designed to allow for the future road widening.

The idea of building the $6.4 million roundabout is to reduce collisions by eliminating left-hand turns across oncoming traffic. Both Highway 44 and 633 carry a combination of commuter traffic and heavy load vehicles.

Roundabouts are tricky to manoeuvre round for drivers who are unfamiliar with them, but Alberta Transportation has guidance on its website, “how to use roundabouts.”

The province’s other roundabouts are at Highway 8 and Highway 22 west of Calgary, built in 2007, and at Sylvan Lake and Peace River, both built in 2008. Other provinces, including Quebec, Ontario and Prince Edward Island have also installed roundabouts in recent years.