Roundabout Woes in North Denver

 

Four years ago, one of North Denver’s first roundabouts was installed on 35th Avenue and Raleigh Street, but it did not function like a regular roundabout. To the confusion of drivers and bikers, the original stop signs on the two smaller side streets were left in place, leaving those who entered the roundabout lost on how to use it while still obeying traffic laws. 

Comments from four years ago point out the design flaws in the roundabout on 35th Avenue and Raleigh Street. (Source: Streetblog Denver.)

According to guidance from the American Society of Civil Engineers, a modern roundabout is a free-flowing intersection in which traffic approaching the roundabout from any direction must yield to traffic already in the circle. The addition of a stop sign is confusing to users and suggests that Denver didn’t take the time to truly understand how a roundabout works before implementing them. 

“To truly create safety on streets, roundabouts are a great option that naturally allow for the slow flow of traffic,” said Chuck Marohn, Strong Towns president and retired civil engineer. “They keep cars moving, but at speeds at which they’re extremely unlikely to seriously harm anyone. If cities put in the effort to do it correctly, what you have is a really sound strategy for turning local streets into safer and more productive places.”

Another traffic circle on Newton and 35th Avenue in Denver. The stop sign was eventually removed after the city realized the confusion it created. (Source: Google Maps.)

A roundabout can be both safer and more comfortable for drivers and walkers alike, but only if the engineer designing it knows how to integrate walkability into the roundabout.

“The priority should be slow speeds; the geometry of the roundabout needs to be tight to require drivers to slow way down and look around,” said urban planner and Strong Towns Editor-in-Chief Daniel Herriges. “And pedestrian crossings need to be highly visible to drivers entering or leaving the roundabout. There are good design precedents for all of this—none of it is rocket science. But a poorly designed roundabout is going to create a less safe environment.” 

Example of a larger Dutch roundabout with bi-directional cycling lanes.

To Denver residents, these roundabouts have the opposite of a street-calming effect. At a roundabout on 16th Avenue, a biker reported that there was not enough space for a driver and biker to cohabitate in the roundabout together. To go around the traffic circle, a vehicle would need to pull into the bike lane, which led to cyclist Paul Frazier getting hit by a car in 2021

Rodney Kazenske, architect and chair of Sunnyside United Neighbors Inc. (SUNI) Land Use Committee, said neighbors have reported drivers hitting the outer curb, sometimes causing a flat tire, as they try to avoid hitting roundabouts constructed in tighter areas. 

“Getting the details right will save drivers and bicyclists from roundabout confusion and frustration,” said Marohn. “Getting them wrong runs the risk of discrediting roundabouts as a valuable tool in the eyes of community members.” 

Denver is learning from their mistakes, albeit slowly. Many of the roundabouts in North Denver have been installed for a number of years, and just within the past couple of months, the city removed the accompanying stop signs. Now, roundabout users are in a position of unlearning the habits they’ve already built to accommodate the traffic circle confusion. 

Kazenske said, despite the stop signs now being removed, he still experiences drivers being confused in the roundabouts: “I just biked this morning to and from a meeting at a local coffee shop down 41st Avenue, where several of these roundabouts have been installed. Twice, I experienced the same situation where I was arriving at the intersection just slightly later than a car arriving from the cross street. Both times, rather than merge into the roundabout slowly, and continue around the circle, the cars stopped—right in the roundabout. Even though they obviously had the right-of-way. I know they were doing it to be nice to me as a biker, but it just led to more confusion because I was prepared to slow and stop to allow the car to proceed. And now here they were completely stopped right in the roundabout. Exactly the opposite of what should happen to traffic.”

“If North Denver is working to create calm, slow neighborhood streets, then they’re moving in the right direction,” said Herriges. “But it’s troubling to hear how long it took to fix such a simple, obvious issue as a misplaced stop sign.”

A bottom-up, Strong Towns approach recognizes that success over the long term is best built incrementally. “By purposefully and thoughtfully implementing street safety measures that are also receptive to feedback,” said Herriges, “the problems that present themselves will be early, small, and fixable.” 

Northside Denver has a lot to learn when it comes to implementing street safety measures. Kezenske said, “As a society we just need to get better educated as to the proper etiquette of car–car and car–bike interactions at roundabouts. And maybe that just takes a little time.”