A state route marker is,in the United States,an icon or shield used to show motorists that the route is controlled by the state(For example,Kentucky State Route 20 a circle with "20" in it) A state highway in the United States is a numbered highway primarily administered by a state government. ... The Savior Not Made By Hands (1410s, by Andrei Rublev) An icon (from Greek εικων, eikon, image) is an artistic visual representation or symbol of anything considered holy and divine, such as God, saints or deities. ... Indo-Persian Dhal Shield A shield is a protective device, meant to intercept attacks. ...
State route markers vary by each state. A list is shown below
Originally, the route came into St. Louis via Edwardsville, Mitchell, down what is now ILL 203 to Veterans Bridge and later across the Chain of Rocks Bridge, but later moved south and the original route was called Bypass 66.
Route 50 still exists and goes north toward Washington, so don't fall under the spell of the old road appearance into thinking that is old Route 66.
Route 66 can be reached on the east side of Flagstaff from the interstate and you follow the old road on the north side of the railroad tracks.