Coralville drivers over the past decade have been experiencing changes in how they are getting around.
City engineers are constructing more roundabouts instead of typical signalized intersections. Last week, the city opened its seventh roundabout to traffic located west of Heartland Place along Heartland Drive. This latest roundabout is the third one constructed this year and the city is eyeing more intersections where roundabouts would make a good fit.
“We’re not necessarily looking at just roundabouts,” said Scott Larson, assistant city engineer. “We’re looking at improving traffic flow or addressing some other issue at an intersection that is currently only controlled by stoplights.”
Roundabouts are much like they sound, unsignalized, circular intersections and traffic engineers say roundabouts increase safety while minimizing traffic delays.
Larson says he likes roundabouts for their traffic calming effect and improving traffic flow while providing aesthetic enhancements to the land in the center. Roundabouts tend to make drivers slow down compared to stoplights, where drivers can speed to make it through a yellow light.
“At a roundabout drivers don’t do that as often…you’re not trying to beat a signal,” Larson said.
Tim Simodynes, who works in the office of traffic operations in the Iowa Dept. of Transportation, previously spent 15 years as a safety engineer with the department and said Iowa has roughly 50 roundabouts with the first ones being constructed in early 2000.
Simodynes said unlike the huge traffic circles like Paris' Arc de Triomphe, most “modern roundabouts” throughout the United States are purposely constructed to be smaller.
“The modern roundabout is really different,” he said. “It’s smaller design is based on speed to yield on entry and free flow on exit,” he said.
Coralville’s first roundabout was constructed in 2002 at the intersection of First Ave. and Holiday Road. Data from the Metropolitan Planning Organization of Johnson County shows 23 collisions have occurred since 2003 at the intersection, which is an average of 2.3 collisions per year. MPOJC’s collision data goes back to 2003 and couldn't compare the crash data of First Ave. and Holiday Road intersection before it became a roundabout.
The East Ninth St. and Quarry Road roundabout – in the Iowa River Landing -- had one collision since it opened in 2006, while the remaining five roundabouts report no collisions.
Larson said city engineers plan to convert a four-way intersection at Commerce Drive and Commercial Park into a roundabout, which should be completed next summer. MPOJC data shows the intersection had four crashes at the intersection since 2003. The city is contemplating adding a roundabout at the intersection of First Ave. and Oakdale Blvd as traffic from North Liberty continues to grow.
The Federal Highway Administration says converting a two-way stop control mechanism into a roundabout can reduce severe crashes that cause injury or fatalities by 82 percent and overall crashes by 44 percent. Converting a signalized intersection can reduce severe crashes by 78 percent and all crashes by 48 percent.
Jacob Knosp, a research and development brewer and bartender for Backpocket Brewing, and a co-worker saw a collision at the roundabout outside of their Iowa River Landing brewery last week when a car didn't yield properly. The 30-year-old said he prefers roundabouts, but thinks there needs to be more driver education about them.
“They’re fine," Knosp said of roundabouts. “People that don’t know much about them hesitate and that’s when they get into an accident.”
Larson said yielding to cars is one of the most important rules to keep in mind when driving in a roundabout. He said constructing more roundabouts will help drivers get used to them.
"I think it's just something over time people will become more accustomed to seeing," he said.
Roundabouts in Coralville: