The Waverly City Council will determine during Monday’s meeting whether to reconsider the Aug. 6, 2018, decision to convert Bremer Avenue from four lanes to three.
Both the Iowa Department of Transportation and a group of Waverly citizens who oppose the conversion have provided to the council data that tell different stories of how what is called a “road diet,” in traffic engineering terminology, has impacted traffic along Iowa Highway 3 through town.
The DOT shows that from Oct. 29, 2018, which is when the reconstruction of Bremer Avenue was considered complete, through Aug. 5, there is a 20% reduction in motor-vehicle accidents versus the average from 2008 to 2016.
However, Keep Waverly Moving, the road diet opponents, contends that when unreportable crashes are taken into account, there was actually an increase of up to 15%.
But how should the city evaluate the effectiveness of the current three-lane configuration? Should Bremer Avenue return to four lanes, or was the recent traffic congestion problem a temporary annoyance that has since been solved after all fixes, such as the re-opening of the Adams Parkway Bridge and the soon-to-be-opened Cedar River Parkway, are applied?
Perhaps the most contentious point in the ongoing dispute between the state and KWM has been crash data in the focused corridor.
In an email to Waverly Newspapers sent on Monday afternoon, Nick Humpal, assistant DOT District 2 engineer, said that the average number of accidents per year on Bremer Avenue between Heritage Way/20th Street Northwest and Eighth Street on the east side of the Cedar River — the area that was reconstructed during the 2017 and 2018 road construction seasons — was 41 in the nine-year span being studied. The two years that work occurred were not used on the analysis.
Humpal then used two sets of data to compare the post-construction crashes and projected them out for a full year. The first set used a six-month period through April 29, during which there were 14 accidents, which became a 28-crash annuitized figure. That amount would lead to a 31% reduction, well within the 19-47% range that the agency has seen with other similar road diets.
Then, the DOT used the observations that went through Aug. 5, which was the latest data available. The accident count there was 26, of which 12 happened during the May 6-June 28 construction window for the Adams Parkway Bridge. During that time, Humpal reported that traffic increased on Bremer Avenue by 25-30%.
When projected through Oct. 29, the anniversary of the road’s completion, that would equate to about 33 crashes, leading to a 20% reduction to average, right on the low end.
“It’s important to note that our analysis is based on crash data reported by Iowa Code 321.266 and does not include unreportable crashes,” Humpal said. “When we review crashes at intersections, roadway segments, or even statewide, we use crashes as reported to the State of Iowa, as required in Iowa Code 321.266.
“This code section requires any crash occurring anywhere within the State of Iowa causing death, personal injury or total property damage of $1,500 or more to be reported to the state. These are the same crashes used by Iowa State University and the University of Iowa when they analyze vehicle crashes as part of their research projects.”
However, members of Keep Waverly Moving, which is founded by Neighborhood Home owner and candidate for Waverly City Council at-large Matt Schneider, believe that the state’s figures are underreported. In a document sent to the City Council and obtained by Waverly Newspapers on Aug. 9, they included four additional data sources for its analysis, on top of the DOT’s: a 10-50 crash report list from the Waverly Police Department, the police logs published in Waverly Newspapers, reports by individual citizens and the city’s own figures.
“The crash increases have been consistent since the start of the road diet,” the document read. “Some point-in-time measurements were reading unusually high. We should be cautious about drawing any conclusions from short time frames.
“We have been tracking this on a regular basis from the beginning and the average of what we see is crashes up over 40% or more against a recent time frame. With DOT-reported crashes being up, but not nearly as much. We believe this is because the median severity of crashes has shifted down.”
However, KWM broke down the survey period that the DOT used into three separate three-year periods to show trends. Between 2008 and 2010, the average was 50 crashes per year, while it was 34.3 between 2011 and 2013 and 34.6 in the last three pre-construction years. There was a high of 54 in 2009 and a low of 26 in 2012.
“It appears Bremer Avenue didn’t have a crash problem, as the DOT suggested,” KWM said in a statement. “Crashes have been trending down on Bremer Avenue until the road diet.”
When looking at the first seven months of post-construction, through May 31, KWM observed that there were 21 crashes within the defined corridor, translating to 35.8 for a 12-month period. That equates to a 9.8% reduction in crashes.
The document also notes that when the time between January and May are taken out from the overall numbers, they found an 11.1% increase in crashes, and when using the last three years of data, that resulted in a 15.3% increase.
“When you weigh that up against previous years you can see that we are outpacing some years, and some years we are unchanged,” the KWM document stated. “In short, serious crashes have not reduced on Bremer Avenue and appear to up some.”
The document was first shared with city officials and the DOT in early June.
Following a correspondence between Humpal and Schneider, in which the engineer told the businessman that his initial conclusion — of a larger discrepancy between KWM’s study and the DOT figures — was off.
“You’ve identified 123 fewer crashes from 2008-2016 because you fail to count multiple crashes that occur at the same location that may be identified with a single crash point,” Humpal explained. “One crash point does not necessarily represent one crash, it could, and in many cases, does represent the location of multiple crashes. Further explanation of showing how to identify which points may represent multiple crashes is identified in the attached document described as Map Configuration – Stacks…
“We stand behind the information and analysis we’ve shared with the Waverly City Council, staff, and residents.”
KWM revised their study, and shared it with the city on June 11.
The entire report can be found on waverlynewspapers.com.
Humpal said some of the early traffic problems have mitigating circumstances. He first noted that this past winter had above-average snowfall — in fact, record snowfall was measured at the Waterloo Regional Airport — as well as the lane markings being washed or scrubbed away, due to the difficulty of putting them on new pavement so late in the year.
He added that the disruptions from the Adams Parkway construction and the reconstruction of the pedestrian ramps at several intersections also contributed some. However, the DOT and Waverly Utilities have retimed the stoplights along the corridor which Humpal said has appeared to partially alleviate the issue.
Plus, he said this week’s opening of the Cedar River Parkway will have an “unknown impact” on traffic and crashes in the Bremer Avenue corridor. The east access will be near the GMT Corporation plant, with it continuing through the intersection of 10th Avenue Southwest and Heritage Way near the CUNA Mutual campus.
“In conclusion, the small sample of crash data on the (Highway) 3 three-lane should be used with caution, due to the random variability of crashes,” Humpal said. “As is evident in the baseline crash data, crashes will fluctuate from year to year and even within a single year.
“We see this same variability in crashes on (Highway) 3 and as we have more time and data available, we will continue to monitor and evaluate the crash data.”