Guide and Information Signs: Route Markers, Destinations, and Services
Guide and information signs: where you are and what is ahead
Guide signs are green with white legends and give destinations, distances, exit numbers, and route names. They are not commands; they help you plan lane changes early. Blue signs mark motorist services-fuel, food, lodging, hospitals, rest areas. Brown signs mark recreation and cultural areas. In Oklahoma, Interstate route markers are the red, white, and blue shield; U.S. routes use the white shield with black numerals; state routes use Oklahoma's own marker, so read the number and direction rather than relying on color alone.
Exit signs often include an exit number, a destination, and an arrow or "EXIT ONLY" panel. A yellow "EXIT ONLY" panel means that lane must exit; if you want to continue, move left before the gore area. Mile markers are small green signs used to report locations in an emergency. Service signs may show gas, diesel, EV charging, or accessible facilities.
Worked example: A green overhead sign reads "Tulsa 38 | Joplin 112" with the right lane marked "EXIT ONLY" for I-44. You want Tulsa. The destination is straight ahead, so ignore the exit-only lane and move to a through lane. If you had already entered the exit-only lane, continue and re-enter legally rather than cutting across the gore.
Traps: using a blue service sign as a route marker; assuming a brown sign is a warning; reading only the top line of an overhead sign; and crossing the painted gore to recover from a late exit. Guide signs are read at speed-scan them early, but never stop in a travel lane to read one.