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Web posted
The planned reconstruction of the Dowling Road interchange will include two tear-shaped roundabouts on either side of the Seward Highway overpass. Alaska's first roundabout was constructed in 2001 at the intersection of Southport Drive, Washington Avenue and Maritime Loop. Roundabouts are circular intersections that take the place of intersections with traffic lights or stop signs. The Dowling roundabouts are tentatively scheduled for construction this summer. The contract, however, which was awarded to Quality Asphalt Paving, stipulates that if the roundabouts cannot be finished by August, construction has to be put off until next year, according to Michael Tooley, highway construction engineer for the DOT.
Anchorage drivers' initial experience with the Southport roundabout was a bit rocky. The first winter resulted in several accidents, including the loss of a number of light poles around the circle. In response, minor modifications were made to the roundabout in 2002. Joel Stout, a project manager with Lounsbury & Associates, designed both roundabouts. He said that many of the initial problems at Southport were due to drivers failing to obey the recommended speed limits around the circle. The ideal speed in a roundabout is 15-20 miles per hour. The minor design changes and the adjustment period seem to have solved the problems initially experienced at the Southport roundabout. "When they (roundabouts) first open, there is a transition period. A year later, nobody thinks about it," said Stout. The transportation department, in conjunction with Lounsbury and Quality Asphalt Paving, is taking several steps to prevent the initial difficulties with the Dowling roundabout. One of the courses of action will be to launch a heavy education campaign to the public before the roundabouts open, said Tooley. "It is going to be tough for the public to get used to because it is fairly complicated," he said. "We hope with education and time, people will bear with us till they get used to it." One of the stipulations of the construction contract was that the contractor had to hire a public relations firm to assist the education efforts, Tooley said. The companies will distribute a brochure to the public that explains the principles of the roundabout. The basic idea is to yield to the left with those inside the circle having the right-of-way. The DOT has also designed user-friendly street signs to assist drivers in navigating the intersections. "One thing we are trying to do is to improve how signs inform people what is going on," said Stout. Stout, lauded by the Alaska Professional Design Council for his work on the roundabouts, has designed a Web site to assist in the education of the public. The site (www.alaskaroundabouts.com)contains information describing the use and benefits of roundabouts. Stout has also made some design modifications which he believes will help make things easier for drivers. One design change, which was implemented with the Southport reconstruction, was to make the inside curb around the circle higher to prevent larger vehicles from driving into the center circle. Another change in the design was to add crowns in the pavement, which will naturally guide drivers around the curves, Stout said. This should, in theory, also help drivers from sliding to the outside of the circle on icy roads. The Dowling Road improvement project began last year with the intersection of Lake Otis Parkway and Dowling. The $12.7 million construction project will extend from that intersection to the Campbell Creek Bridge on Potter Drive and will include widening much of the road to four lanes. Construction is slated for completion in mid-2004 with the majority of the work being finished this year. The total project cost for the Dowling Road upgrade is $29.6 million. The cost includes $6.9 million for right-of-way aquisition and roughly $10 million for utility relocation. Benefits of roundabouts Roundabouts are becoming increasingly popular in American cities. Studies have shown that roundabouts as opposed to intersections with signals or stop signs are not only safer, but also more cost effective. "There is not a state in the union that is not actively looking at that and trying to gain those benefits," Stout said. The Insurance Institute for Highway Safety conducted a study of 24 intersections in the United States before and after the construction of a roundabout. The study, released May 13, 2000 concluded that collisions were decreased by 39 percent and injury-causing accidents were decreased by 76 percent. The study also showed that delays in traffic were reduced by as much as 75 percent. Roundabouts have also proved safer for pedestrians. The Insurance Institute analyzed crashes around the country and found that fewer than 2 percent of pedestrians who were struck by cars died in crashes that occurred at less than 25 miles per hour. The design of the Dowling roundabout places pedestrian crossings a full car length behind the yield sign, meaning that cars merging into the circle do not have to worry about pedestrians and the pedestrians have a safer walkway. Another benefit to the roundabouts is cost effectiveness, according to its designer. The roundabouts will save about $1 million from the total Dowling Road improvement project cost, said Stout. By implementing the roundabouts, the contractor can avoid widening the road that runs underneath the Seward Highway overpass. This prevents having to build new walls under the overpass, which is both time-consuming and expensive. It will also eliminate the two traffic signals on either side of the overpass that cost up to $15,000 each to install and about $5,000 a year per light in electricity and maintenance, Stout said. The south Anchorage roundabout cut the total Southport project cost by 40 percent, according to Stout. The efficiency of the roundabout design allows for an improved traffic flow, which eliminated the need to widen the road from two lanes to four.
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