Does Historic 66 (St Louis) follow I-44 between exits 261 & 264, or the frontage road? The map at
this link makes it look like it's on the interstate between exits 261 and 277A, which would mean it's missing the shaping point that I-44 (and US 50) have for that segment.
Looks like there's another broken concurrency with Business 44 in St Robert, between I-44 exit 159 and the Business Spur to Ft Leonard Wood, and another one along Business 44 in Springfield just west of MO 13.
