When the Iowa Department of Transportation identified an opportunity to rehabilitate and resurface Iowa Highway 14 through Knoxville, the project became more than a pavement improvement effort. It also created the right moment to rethink how the corridor functioned for drivers, pedestrians, and the community as a whole. Snyder & Associates played a key role in evaluating and advancing that vision, providing the traffic analysis and planning support needed to transform the existing four-lane undivided roadway into a safer, more efficient three-lane facility.
Corridors with four undivided lanes can experience more conflicts and higher crash potential when traffic volumes no longer justify two through lanes in each direction. Along this stretch of Highway 14, traffic conditions indicated that a four-to-three lane conversion could maintain similar operational performance while improving safety. Following milling and overlay of the existing asphalt surface, the corridor was restriped to provide one through lane in each direction with a center two-way left-turn lane, all without widening the roadway.
Data-Driven Analysis Confirmed the Best Path Forward
Snyder & Associates conducted a comprehensive traffic operations analysis to evaluate whether the conversion was feasible and appropriate. The study included a review of traffic volumes, turning movements, vehicle classifications, corridor speeds, and truck percentages. That work confirmed traffic demand along Highway 14 fell within established thresholds that support a three-lane cross section and showed the reconfigured roadway could perform similarly to the previous four-lane layout from an operations standpoint.
Public engagement was also an important part of the process. Community meetings helped communicate the purpose of the project, explain expected operational changes, and share the safety benefits of the new roadway configuration. That early outreach helped build understanding around how the corridor would function after construction and why the change made sense for Knoxville.
Modern Signals & Safer Pedestrian Crossings
In addition to the lane conversion, the project included several important upgrades that improved traffic control and multimodal safety along the corridor. Six signalized intersections were modernized with updated equipment, including protected-permissive left-turn operations using flashing yellow arrows on Highway 14 and coordinated controllers that allow the signals to work together more efficiently. These improvements support better progression and reduced delay for motorists traveling through the corridor.
Pedestrian accommodations were also significantly enhanced. The project included updated crosswalk markings, pedestrian pushbuttons, countdown signals, improved signage, and ADA-compliant curb ramps designed to meet current accessibility standards. A new mid-block crossing at the Competine Trail added another important safety element, featuring a refuge island and a rectangular rapid flashing beacon (RRFB) to increase driver awareness and yielding rates. At a nearby railroad crossing, the raised median was extended through the crossing to discourage drivers from bypassing activated gates. Together, these features created a corridor that better serves all users.
Measurable Results for the Community
The completed project reflects a strong collaboration among the Iowa DOT, the City of Knoxville, Snyder & Associates, and the local community. Its benefits are already being seen in day-to-day travel through the corridor. After implementation, there was a decrease in crashes, including a 31% reduction in injuries. These results reinforce the value of applying lane reconfiguration strategies when supported by data and corridor conditions.
City Manager Heather Ussery has seen those benefits firsthand.
“The city has been pleased with the transition from four to three lanes along Highway 14. We’ve observed smoother traffic flow and a 31% reduction in injuries through the corridor. This conversion also allowed for the city to implement a safer pedestrian crossing to further our trail system, which has been heavily utilized.”
Her perspective reflects the broader outcome of the project: a corridor that not only functions more safely and efficiently, but also better connects Knoxville residents to the places they want to go.
