Olathe Improves Capacity on 159th Street with Redesigned Intersection

The City of Olathe, Kansas was facing capacity issues at the 159th Street and Blackbob intersection. The four-way stop was busy during typical peak hours and was even worse on weekends due to youth sports events in the area. Traffic was slow, and a new design was needed to increase flow and improve safety.

Affinis began the Olathe-based project by conducting a traffic study for the area. We considered a variety of solutions, including roundabouts, traffic signals, turn lanes, and no turn lanes. Based on our findings, we decided to use a traffic signal and add left-turn lanes in all directions.

In designing this project, we encountered a few challenges. The first was related to the project’s location. Part of the site is on park land. While most cases like this are classified as 4F under federal regulations, this one had a 6F designation. This meant the city would have to provide additional park land elsewhere as a trade for this section. Olathe’s interests aligned with Johnson County’s, and they were able to swap land for this project.

Another challenge was relocating utilities. Evergy had overhead and underground lines in the area. In fact, an underground vault that was 10 ft x 10 ft had major lines coming out if it. Working with the city’s project manager, Therese Vink, and their utility coordinator, Brent Barry, we partnered to find a place to move their facilities that would work well with the new design.

In addition to the traffic issues, the area needed a few other improvements. To minimize the construction impact, we included those upgrades to our plans as well. The project included the addition of an enclosed stormwater system and the relocation of a water line. We also added sidewalk, lighting, crosswalks, and shoulders to increase safety.