CLINTON — The most recent crash data for the Iowa Department of Transportation can be found on its website with accident numbers from 2004-2008. These totals are also illustrated on maps, and on the basic map, each accident location is notated by a small, yellow dot.
When it comes to the city of Clinton, certain clusters of dots seem to appear as expected. Heavier collections are found in the heart of the downtown, and they space out on the less traveled outskirts.
Then there’s a collection on the northwest side of Clinton, near the Clover Hills Shopping Center. Over a dozen yellow blips form a straight line where no roadway actually exists.
The cars they represent didn’t fly hundreds of feet off the nearest roads: The frequency of accidents at the closest intersection — 13th Avenue North and North 11th Street — was so high that the department had to line the dots in open space for them to fit.
“This is the only location in town that warrants a signal... and it would benefit from having a traffic signal added to it,” said Jason Craft, Clinton City engineer.
When the DOT announced Tuesday that 46 road projects in Iowa will receive a combined $8.7 million in assistance from the Traffic Safety Improvement Program, it was little surprise that 13th Avenue North and 11th Street made the list. Of that chunk, Clinton will receive $175,000 to install permanent traffic signals and “protective/permissive left turn phases for north- and southbound traffic” at the intersection. Craft said he’s planning to start construction in July 2014 when the new fiscal year kicks in.
Thus, Clinton will mend another hazardous roadway.
But another major win, said DOT media contact Terry Ostendorf, comes through what he called “the benefit cost.” He said now Clinton can fix a major traffic concern with minimal funding.
“The benefit valuation is the financial savings of fewer crashes compared to the cost of revision,” Ostendorf said. “Typically we look for a 1.5 to a 1.8 ratio as being a quality benefit cost. This intersection surpassed that quite a bit.”
According to Ostendorf, the intersection graded at 1.97, well above what the department looks for when designating TSIP funds. With 27 accidents from 2004-2008 (and more following), it ranked as the city’s 23rd most hazardous roadway during the time of the study, and has likely moved up since Clinton has amended some of its more pressing road hazards.
Back then, it had the eighth most accidents of any city roadway (no fatalities, one minor injury). According to the DOT, almost all of these collisions were “intersection-related” accidents.
-This GoogleMap illustrates the frequency of crashes from 2004-2008.
“Very rarely do we have benefit costs that high,” Ostendorf said. “The benefit cost was such that it was a strong candidate through the review committees. It was deemed to be a quality project.”
Craft’s department drafted the proposal and calculated the benefit cost ratio. He said the intersection would have seen revision even without help from the DOT, especially with looming construction of a new middle school in the area.
“Since we’ve got the funding, we will move forward on planning in this next year,” Craft said.
TSIP is a decades-old state program enacted by the Iowa Legislature. It skims 1 percent off road tax revenues for specific project requests. The highest funding rewarded this year was $500,000 for eight projects in the cities of Iowa City, Des Moines, Ankeny, Carroll as well as Montgomery, Lee and Clay counties.
The money awarded this year will come out of TSIP’s FY 2015 budget.