Missoulians might not have to worry about learning to use roundabouts after all. If the Montana Department of Transportation’s plans for realigning the Arthur/Fifth/Sixth street intersections don’t change significantly between now and the proposed spring 2008 construction date, we might have to learn how to cross a 70-foot intersection at Fifth Street and Arthur Avenue (about the width of Reserve Street) instead.
At an April 4 meeting to discuss pedestrian and bicyclist concerns about the proposed plan—which includes two new stop lights and partial expansion to five traffic lanes—discussion among roughly 45 representatives of the city, MDOT, UM and neighborhood residents circled back to one subject: to roundabout or not to roundabout.
Bob Giordano, director of the Missoula Institute for Sustainable Transportation, presented a citizen’s alternative to MDOT’s plans, including roundabouts at the intersections of Fifth Street and Arthur Avenue and Sixth Street and Arthur Avenue that could accommodate 50-foot trucks—the largest size truck the University needs to access campus, Giordano said. But, said MDOT’s Consultant Project Engineer Mark Studt and colleagues, this project is geared toward realigning Highway 12, and so has to meet federal highway guidelines—which must accommodate 67-foot trucks. A roundabout big enough to allow 67-foot trucks, they said, would require a 130-foot radius and might compromise even more historic homes than the four that will be impacted under the current plan. In fact, Giordano said, according to the Federal Highways Roundabout Design Guide, the guideline for 67-foot trucks call for a 115-130-foot radius; he added that communities have built such roundabouts at just 106 feet .
But the anti-roundabout argument is about more than size. It’s also about road grade and safety and, as one of MDOT’s presentation points read, the fact that roundabouts are “unfamiliar technology for diverse user group.”
“A roundabout has got a big learning curve about it,” said Six Mile Engineering Project Manager Jeff Jones, such that people will ask, “What do I do when I get in this?”
Director of ASUM’s Office of Transportation Nancy Wilson, however, expressed concern about another question: How will the crossing at Arthur Avenue and Fifth Street, which is now about 30 feet, remain pedestrian-friendly when it more than doubles in size?
These questions remain open for public comment through April 13 (e-mail Mark Studt at firstname.lastname@example.org), and a public hearing will be scheduled in the beginning of May.