Colorado Public Works Journal, Spring 2021

10 | Colorado Public Works Journal by Kevin Simpson Colorado Roundabouts Images © Andy Colwell Although it had been in use in the U.S. for more than a century, Americans still hadn’t warmed up to the idea. A planned King Soop- ers store whose entrance would be on one of the proposed round- abouts along South Golden Road pushed back with concerns about how the unusual intersection might discourage customers. Five years earlier, local businesses had shut down talk of using roundabouts to revamp the road, a broad swath that invited speed- ing, featured intermittent traffic lights and enough lanes to make pedestrian crossing an adventure. But this time, the city cut an unusual deal: If the grocery store didn’t hit its sales targets, the roundabout would be removed. It’s still there today—part of the early wave that, decades later, continues to gain traction in Colorado and around the country as both state transportation officials and especially municipalities embrace this once-unfamiliar solution that, in many situations, calms traffic and leads to fewer injury accidents. Four years after Golden’s roundabouts opened, Alex Ariniello, then a traffic consultant on the project, published a study—“Are Round- abouts Good for Business?”—that’s still widely circulated as evi- dence that they not only enhance flow while reducing speed and result in improved safety, but also can contribute to commercial success. “There is always apprehension in communities that don’t have them, that haven’t had experience with them,” says Ariniello, now the pub- lic works director in Superior, where his influence is evident in the town’s several roundabouts. “We found that people just didn’t under- stand them or weren’t familiar with them. ‘Why are you forcing this on us? Why not a traffic signal?’ That was the typical reaction we would get. “The general public didn’t understand the concept and why it’s a safer intersection type than a four-way stop or traffic signal. I spent a lot of time educating people.” Though introduced to the state in Colorado Springs in the late 1980s, the roundabout concept has been improved upon over the years and began a resurgence in the following decade, as traffic engineers sought to regulate vehicle flow more effectively through trouble spots and to employ the inherent safety advantages of a sys- tem that lowers speeds and virtually eliminates broadside crashes. As their popularity has grown, some states have legally designated roundabouts as the default option—meaning that they’re considered the optimal solution for intersections with the burden on other possibilities to be proven better. Ariniello, who serves on a subcommittee of the Vision Zero project seeking to eliminate traffic deaths, says he’s pushing for a “round- In the late 1990s, the city of Golden considered what then was a foreign concept: The idea of placing roundabouts, the circular traffic control configuration popular in Europe and Australia, along one of its arterials through a commercial center.