Ahead of schedule
Wanker's Corner roundabout will challenge drivers initially, but will be safer in long run, engineers say
Even though it might seem like the roundabout being constructed at Stafford and Borland roads is nearing completion, the project manager says it will not be finished until the fall of 2009.
The roundabout at Wanker's Corner will serve traffic coming from the cities of Lake Oswego, West Linn and Tualatin as well as I-205. The crossroads has such a high volume of traffic, according to Clackamas County Civil Engineer Vince Hall, that it has been a chess game trying to build the intersection without significantly impeding traffic.
Even so, Hall says construction is currently ahead of schedule. As project manager, he oversees and administers the project, which has been in the making for at least three years.
What may seem like excess time was caused partly because of delays due to a change of design and partly because it is a very popular intersection and difficult to construct while it is being used.
'This is one of the more congested intersections in the county,' Hall said. 'But the roundabout will help traffic flow.'
Initially the junction of these two popular roads was approved as a single-lane roundabout, an off-site improvement imposed as a condition of approval when the Rolling Hills Community Church was built on Borland Road. The church budgeted about $1.5 million for construction costs.
Later, however, county traffic engineers decided that the volume of traffic would increase after the roundabout was built. That's when they decided that it should be the county's first two-lane roundabout, and they budgeted $4 million for the traffic circle, with the additional $2.5 million coming from the fees that developers pay.
'Based on traffic projections,' Hall said, 'there is a bigger traffic volume projected here. It might be a little bit early (to build so large), but we didn't want to have to come back and rip up the intersection in a couple of years and build it bigger.'
The two lanes, Hall says, shouldn't confuse people. There should be no reason to change lanes while turning around the circle, he said, because it is similar to a traffic signal with left-turn and right-turn lanes.
'If you need to make a right turn, approach the intersection in the right lane,' Hall said. 'If you need to turn left, approach the intersection in the left lane. If you want to drive straight through, you may approach the roundabout in either lane.
'There will be signage, just like a signaled intersection, and there will be marks on the pavement, so that people will know which lanes to get into ahead of time.'
The two-lane roundabout will handle pedestrians and bicyclists in relative safety along with vehicles of various sizes - including long 18-wheel semi-trucks. But to remain safe, Hall says people will have to follow the signs and some simple rules.
Bicyclists can either stay in the middle of the lane and flow with vehicular traffic or move to the sidewalk and enter the pedestrian area, walking across traffic lanes in the crosswalk. Pedestrians have a refuge area in the central 'splitter' islands, which help drivers stay in the correct lanes of traffic.
'Just like any intersection, whether it's a roundabout or signal, the first six months there is a lot of confusion,' Hall said. 'There's a learning curve for the public.'
There also could be a higher accident rate in the first few months, he said, while drivers adjust to changes.
But there are so many advantages to this type of crossroads intersection that county engineers now prefer to construct rural area roundabouts.
Among the pluses are slower vehicle speeds, fewer conflict points and reduced severity of conflicts. Those advantages, according to a 2006 study, mean from 40 to 50 percent fewer crashes and from 70 to 80 percent fewer injury crashes.
In addition, there are fewer and shorter delays, compared to a signalized intersection as well as less pollution due to shorter idling times. And a roundabout can enhance the community, with its landscaping features and less concrete.
The new intersection also will reduce travel times and be safer than a signalized crossroads.
'At first, people may feel a little uncomfortable, just because it is new,' Hall said. 'There's no question that they felt uncomfortable when the roundabout was built at Rosemont Road.'
Meanwhile, daily construction continues at the intersection. During August, Hall said, workers will be focusing on the western portion of the area, adding curbs and paving. By September, drivers may find themselves driving through the incomplete roundabout on one lane, instead of its eventual two-lanes.
Workers also will be building those concrete 'splitter' islands at the approaches to the intersection. And then, when the weather becomes inclement and limits work, Hall says that delay should not affect the completion date because the project is now ahead of schedule.
For more information, visit http://www.kittelson.com/kai_toolbox/roundabouts/index.htm or call Hall at 503-353-4650.