Exit 232B from Interstate 35 is a diamond interchange with traffic lights north of the Johnson County line, just inside Kansas City. This diamond interchange serves as the northern terminus of Roe Boulevard from Roeland Park, as well as the southern terminus of the 18th Street Expressway. US-69 northbound leaves I-35 northbound at this interchange, turning north to travel along the expressway. The expressway bridges the BNSF rail line as well as Merriam Lane, and has a partial diamond interchange with the latter (the ramps from Merriam to southbound 18th Street and from northbound 18th Street to Merriam are omitted due to the proximity of the I-35 interchange).