Kehrs Mill/Long Road at Wild Horse Creek Road

Long Road/Kehrs Mill Road at Highway CC (Wild Horse Creek Road) is an offset intersection with State Hwy CC. As growth has continued westward in St. Louis County, the two T intersections have experienced severe traffic congestion. Presence of two traffic signals at these intersections creates inefficient traffic movement for vehicles traveling on Kehrs Mill Road and Long Road, resulting in vehicles stopping twice. Burns & McDonnell was retained by St. Louis County Department of Highways and Traffic to improve the intersection configuration and increase capacity on Long and Kehrs Mill Roads.

Burns & McDonnell developed two alternatives for the project. The first alternative would realign Long Road and Highway CC to make this the through traffic movement. Kehrs Mill Road would tee into the realigned Long Road, and Highway CC would tie into Kehrs Mill Road. This alternative would support the highest traffic movement from east bound Highway CC to north bound Long Road. The second alternative would realign Long Road to create a four-way intersection with Kehrs Mill Road and Highway CC. Both alternatives required purchasing right-of-way and easements.

Safety of pedestrians and bicyclists is a primary concern in this fully developed area, particularly once the road is widened. The conceptual design considered sidewalks and multi-use paths on one or both sides of the road, and recommendations were made for a two-way multi use path on one side of the road due to physical constraints in the area. Accommodations were made at the railroad tracks for the bike paths. Pedestrian mazes were used rather than standard crossing arms, which could trap pedestrians near railroad tracks.

The project had several design issues that had to be met to maintain the current infrastructure and was coordinated with proposed expansion in the area. The current infrastructure included a railroad crossing 1,000 feet from the proposed intersection of Long Road and Highway CC. Between the railroad and the relocated intersection, Bonhomme Creek crosses relocated Long Road. In addition, the U.S. Army Corp of Engineers (USACE) is constructing a levee along Bonhomme Creek. The relocated Long Road bridge will tie into the USACE levee. The project also faced many challenges with existing underground utilities. A 42-inch water main, fiber optic line and natural gas lines cross parallels to the roadways.