Modified Single-Point Urban Interchange
Arnold, MO

Heavy traffic congestion at an interchange off I-55 in Arnold, Missouri, was greatly reduced as the result of a CMT-designed, modified single-point urban interchange, the first of its kind in the United States. CMT championed the new concept for the proejct, which utilizes three interconnected signals at one intersection to minimize delays and keep traffic moving, after a corridor analysis conducted by the firm compared it favorably to traditional options.

As part of the project, I-55 was widened from two lanes to 5-7 lanes in each direction. Two bridges were also replaced to accommodate the increased traffic. Construction of the $20.7M project was completed while approximately 85,000 vehicles per day continued to travel the roadways. Time-saving measures initiated by CMT were instrumental in the contractor being able to complete construction four months ahead of schedule.

CMT has been awarded five subsequent projects by the city of Arnold based on the success of the modified single-point interchange.