TRANSPORTATION MATTERS for IOWA

Willy Sorenson, a traffic safety engineer at the Iowa Department of Transportation, has been on a mission for the last decade to document and analyze wrong-way driving incidents in order to develop engineering solutions that keep more Iowa drivers headed in the right direction. “The good thing about wrong-way drivers is that the vast majority of them self-correct and there is never a crash or other incident,” said Sorenson. “But because there was very little documentation of wrong-way drivers, it was difficult to get a grasp on the magnitude of the problem. I kept chipping away at this issue because I just always had a sense that this was something we needed to explore further and solve this problem wherever we can. While it may not happen a lot, it’s worth the effort to find out why drivers are confused and do whatever we can to reduce that confusion to prevent people from getting injured or killed.”

Sorenson’s opportunity to begin gathering data came at a meeting in 2010 when Geoff Huff of the Ames Police Department was talking about the number of 911 calls coming into the city’s dispatch center that reported wrong-way drivers. Sorenson said, “I was able to get the 911 call data from 2008 to 2010 and agreed that there was significant wrong-way driving activity on U.S. 30 between Nevada and Boone, with Ames being right in the center.”

U.S. 30 near Boone

U.S. 30 near Ames

The next step was to determine just where and why these drivers were getting on the wrong side of the four-lane highway. Sorenson said, “In 2014 we were able to get funding to install sensors that could detect wrong-way drivers and traffic cameras at 24 points on U.S. 30 between Nevada and Boone. Since then, there have been 228 documented cases of wrong-way drivers on the 25-mile stretch.”

In talking to colleagues and industry partners, Sorenson knew that the data he was collecting was important, but the location and sensitivity of the sensors weren’t adequate enough to identify and treat the “point of entry” locations. 

After analyzing the data, Sorenson showed that wrong-way drivers are not always entering the opposing lane of traffic at a ramp. In fact, the majority of wrong-way drivers on U.S. 30 entered via at-grade intersections or points where two roads merged.

For at-grade intersections, we have made a multitude of enhancements such as large white painted arrows in the through lanes and the installation of larger “do not enter” signs that are angled slightly so that they catch the attention of drivers before they get headed in the wrong direction. “These engineering solutions have significantly reduced the number of 911 calls to the Ames police department and the surrounding county sheriff’s offices related to wrong way driving,” said Sorenson.

Wrong way driver alert in the Cedar Rapids area

Sorenson’s research has been expanded to include Cedar Rapids and Dyersville. He said, “In Cedar Rapids, we had a number of overhead dynamic message signs. We worked with the Cedar Rapids police department and now when they get a 911 call of a wrong-way driver, they call our traffic management center to have a message put up on the signs to warn other drivers that a wrong-way driver is on the road with them. We’re now working with the police departments in Iowa City and Davenport to expand the use of the overhead signs for wrong-way driver notification.”

Example of video analytics detecting a wrong way driver in the red outline and a right way driver in the yellow outline.  Once the wrong way driver crosses the green and white dashed line(s) or enters the red shaded area, an alarm is triggered inside the camera, and an e-mail is sent to DOT staff

In Dyersville, the intersection of U.S. 20 and County Road X-49 was frequently a site for wrong way drivers. “We were able to document about one wrong-way driver each day at this location,” said Sorenson. “With improved signage, we’ve been able to get this number down to about once every two-to-three weeks.  … and we are not done yet with trying to get that even lower.”

But Sorenson isn’t resting on the work that has been done in these locations.  He said, “We recently received $1.35 million to fund enhanced signing and pavement markings at intersections and interchanges.  To determine the locations we would focus on, staff in our office formed a committee to rank each of the 467 interchanges in Iowa for the potential for wrong-way drivers. Of these, 165 locations were chosen.”

Sorenson said in addition to the 165 locations that will receive signing and pavement markings changes, the Iowa DOT will be adding 60 cameras at higher risk locations that will alert staff via email when they detect a wrong way driver. Currently, the information is collected and reviewed to determine if the pavement markings or signage changes are making a difference.

He said, “The next step after collecting and analyzing the data would be to develop a method that would automatically alert the Transportation Management Center and/or Law enforcement to notify them within seconds of the sensor detecting a driver going the wrong direction.”

Sorenson is excited about the future of this technology, but cautions there are a lot of considerations that we must work through, “We want to make sure there are no false calls that would dispatch an officer to a location for something like a sensor being activated by a DOT tractor mowing down the ramp.” He added, “But even if we can prevent one wrong-way crash from killing or injuring someone’s friend or family member it will be worth it.”