Here are some routings not found on maps. These reflect areas in which a major highway was rerouted and the old road became secondary routes.
This is in the Lucerne area in northern Missouri. US 136 was rerouted for a bridge replacement project. The old route became secondary routes A and C.
This is in the area west of Poplar Bluff where US 60 was upgraded to expressway and rerouted. The old route became secondary routes FF, ZZ, OO and U. Another result is a backtrack on MO 21 as it exits US 60 at the north end of the project.
This is in the area north of Ironton where MO 21 was rerouted. Parts of the old route became extensions of secondary routes O and U. SR RA was decommissioned as a result.
Maps adapted from DeLorme Topo USA 4.0.
Page updated 5 July 2009 by G. R. Van