Safety Study Leads to Design – Route 54 Intersection Safety Improvements

The Problem: Missouri Needed a Road Safety Inspection

Imagine… a high-speed rural multi-lane corridor that hosts an assortment of local drivers, tourists, commercial trucks and farm equipment. It has driveways with direct access to the corridor and numerous at-grade intersections. Crashes are common and when they do occur, the crash severity is higher due to this dangerous combination of factors.

If you drive in central Missouri, chances are, you are familiar with Route 54. With an estimated 20,000 vehicles per day, Route 54 is a vital part of the transportation network in central Missouri due to its connection between I-70 and Jefferson City north to Lake of the Ozarks and Osage Beach south. The increased and seasonal popularity of the Ozarks region has also increased traffic, events, attractions and safety concerns.

Solution: Missouri Hired the GBA Transportation Engineering Team

To address these concerns and plan for the future, the Missouri Department of Transportation (MoDOT) hired the GBA Transportation Engineering team as the lead consultant to perform a safety study. The study consisted of five main parts: data collection, existing conditions analysis, public engagement, development of alternative improvements, and suggested recommendations for future implementation. The area of study was 30 miles from Route E (near Brazito) west to Wood River Road (near Lake of the Ozarks).

Transportation Consulting Actions Taken:

• Data collection involved multiple sources. Cole and Miller Counties provided aerial photography, LiDAR and GIS data with utilities and Right-of-Way. MoDOT provided historical plans, 5-year crash history and traffic volumes for key intersections.

• Existing conditions analysis included sorting and evaluating crash types and trends to assist with identifying patterns and factors. Based on this data, the intersections were categorized as a low, medium or high priority. The intent of prioritization was to identify intersections with the most safety concerns to address improvement efforts accordingly.
• Public engagement during the study included surveys (online and in-person), multiple stakeholder advisory group meetings and an in-person public meeting. The sessions created an opportunity to hear from the community, provide roadway safety education and receive feedback.

• Multiple improvement alternatives were developed with geometric and non-geometric improvements to address the safety concerns at individual intersections and throughout the corridor. Using the Highway Safety Manual (HSM) a thorough safety analysis was conducted. This compared observed crashes with expected crashes and predict crash frequencies for proposed improvement countermeasures and determine a monetary crash reduction benefit. This was then used to develop a benefit-cost ratio with estimated construction costs. An evaluation matrix with the project-specific assessment criteria, benefit-cost ratio, agency guidance and statewide Missouri safety goals were used to rank the alternatives. Suggested improvement alternatives generally fell into the following categories: intersection consolidation and/or closures, alignment and profile improvements, median U-turn, grade separation or low-cost short-term solutions.

• The study provided suggested improvements and an implementation strategy using the 30-mile corridor priority needs and the high, moderate and low-cost solutions taking into account that funding may be available in multiple phases over multiple years. The team’s process was flexible to accommodate both quantitative data and qualitative comments and priorities for suggested improvements that meet MoDOT roadway safety goals.

Additional Design Work Awarded

Following the successful completion of the Intersection Safety Study in 2019, GBA was selected to lead the initial design of the suggested intersection improvements. The first phase of design was completed in 2020 for the Allen Rd. intersection with the second phase started in early 2022 for the Hickory Hill/Clark Fork intersection.

Visit the MoDOT website to learn more about this project.