Congestion in the central business district is caused in part by lack of adequate by-pass facilities especially for motor trucks and certain through traffic. In the early days of automobile transportation it was considered necessary to build wide distributor streets around the periphery of the central business district. Twelfth, Market and Delmar have served and will continue to serve this function. Quite recently traffic experts have concluded that a modern need is for a separated grade thoroughfare completely surrounding the business district which will accommodate by-pass traffic and serve as the in-town distributor for the several interstate and local express highways which will introduce an added volume of new traffic into the central business district area.

A plan for modern highway construction of this type has been devised and is shown on Plate Number 19 (The Major Street Plan). The first unit of this construction will be the central section of the interstate highway, i.e., Third Street and its connections northward via Broadway and Mullanphy Street to North Florissant Avenue at 15th Street, and southward via Gravois Avenue extended from Third and Chouteau to the intersection of 18th, Russell and Gravois.

Eventually a loop would be created by extending this separated grade construction westward along Chouteau (or immediately adjacent thereto) to 18th and thence northward to Mullanphy Street.