Denison City Manager/City Engineer Terry Crawford took exception to the reasons the Iowa Department of Transportation gave for why the City of Denison did not receive a share of the funding for the fiscal year 2021 Traffic Safety Improvement Program (TSIP).
The City of Denison had applied for funding to upgrade the traffic signals throughout the town, beginning on the east side and going west.
Among the improvements were to install updated preemption systems and video cameras (video image vehicle detection systems).
The preemption system allows emergency vehicles to send a signal which will trigger a green light for their direction of travel.
The video cameras signal the traffic light controls that a vehicle is at the intersection so it can change the signals. The use of video cameras is seen as more reliable than loop detectors that are under the pavement and which have broken in the past.
The DOT’s notification, in an email from Leilah Armstrong with Countermeasures and Access Management with the Traffic and Safety Bureau, said that the proposed signal improvements along Highway 30 would have a minimal impact on the safety of the corridor.
Her email also said that the safety along Highway 30 would be significantly improved by a conversion from four lanes to three lanes (eastbound, westbound and turning) which could be potentially combined with signal improvements.
Crawford told the city council on Tuesday that the preemption system and the video cameras are two of the biggest safety measures the city can add on the highway.
“We have to go back to the east end where our signals are the oldest and start adding those and getting everything up to grade, especially with preemption so you can have an emergency vehicle approach with confidence that their horn is going to change that signal, and they have to have a confirmation light that tells them they changed the signal,” he explained.
The conversion of Highway 30 from four to three lanes had been an option offered by the DOT in the summer of 2017 before work was done on the route through town in 2018.
In June 2017, Crawford said the decision to go to three lanes or remain with four lanes was entirely up to the city, and the city wanted to keep the four-lane configuration. He said the city office received many negative comments about changing the highway to three lanes and not many positive comments.
On Tuesday, Crawford informed the council that he thought the change to three lanes was a short-sighted comment because the city had already ruled that out.
“It’s not feasible for Denison,” he explained. “The only way we could do that is if we had enough room to put four lanes outside of that like Carroll does on the east side. We don’t have the right of way for that.”
A third point in Armstrong’s email was that the DOT believes several of the signals located off Highway 30 may not be warranted, so it was felt those should be removed rather than investing in them further.
Crawford thought that Armstrong may have been referencing the traffic signal at Broadway and North 15th Street, but he said a lot of traffic goes through that intersection, especially when funerals are taking place at the nearby funeral homes.
Crawford told the Bulletin and Review that the email from the DOT contains many comments that are contradictory to the city’s traffic safety engineering philosophy, which were presented in the grant application.
He added that problems have occurred with the existing preemption systems because of their age and that the upgraded systems can make it better and more reliable. He said at times the preemption systems weren’t always responding correctly.
“We can’t have it fail even once out of 50 times,” he said. “It’s too big a chance. We want a system that’s very reliable for emergency vehicles and the traveling public.”
Crawford told council members he has a lot of education to do with the traffic engineering and safety division with DOT before he submits another application this year.