A roundabout way to avoid collisions
With its latest efforts on Lorne Street now complete, the City of Kamloops is taking a break from roundabouts.
Erin Felker, the city’s transportation planner, said there are no new traffic circles planned for the Tournament Capital in 2013 and 2014.
But, that doesn’t mean they won’t be back at a future date as the city plans future upgrades at intersections.
“Let’s say the traffic volumes have grown to the point where the current stop sign or whatever isn’t meeting the needs — it isn’t providing high enough capacity to get the volume of traffic through the intersection — then, as we’re considering a signal, we also consider a roundabout,” Felker said.
According to ICBC spokeswoman Kathy Turner, roundabouts are “the single-most effective traffic-control device for reducing the frequency and severity of crashes at intersections” because the shape prevents head-on and left-turn crashes.
There are also fewer potential spots for impact, Turner said.
In conventional intersections, drivers have 32 points at which they could collide with each other.
In roundabouts, there are eight.
Kamloops now boasts four roundabouts: The newest at Lorne Street, at Dallas Drive and Todd Road, at Pacific Way and Aberdeen Drive and at Highland Road and Q’Appelle Boulevard in Juniper Ridge.
Juniper’s is the eldest of the bunch, installed in 2001.
While ICBC has data for each roundabout intersection, Turner said it’s still too early to draw conclusions about roundabouts installed as of 2009 or later (as all but the Juniper circle were).
Crash data from 2007 to 2011 provided by ICBC shows few accidents at the Aberdeen and Dallas roundabouts since their installations — in both cases only two collisions were recorded in the years following their installation.
However, the data also shows few accidents in the area beforehand, at about one per year.
The Lorne Street/Third Avenue intersection has a greater accident frequency, though still in the single digits, but Turner said it will take two or three years to assess the roundabout’s impact.
Juniper Ridge’s roundabout, however, is considered by the Crown Corporation to be a success.
Between 2001 and June 2012, there were 25 collisions at the intersection, 19 of which ICBC designated “property-damage only.”
According to ICBC spokeswoman Michelle Hargrave, the intersection was never a problem spot but, when Juniper West was being planned, the city wanted to find a way to accommodate a large increase in car traffic.
The city’s former traffic engineer, Chris Darwent, estimated in December that about 7,000 cars now travel up or down Highland Road, and thus through the traffic circle, per day. “We’re pleased the annual collision frequency has stayed low in spite of the large increase in traffic over the past 12 years,” Hargrave said.
There is one drawback to roundabouts, Felker said.
Depending on the circumstances, they can be far more expensive than a new traffic signal.
“A roundabout takes up a lot more space so, if you’re talking about having to build retaining walls or do major earth works or buying property, then that makes it cost-prohibitive,” she said.
“There has to be a good safety benefit to go with a roundabout rather than a signal.”