Radio-Traffic Information Signs
Radio-Traffic Information signs (see 3‑12 for example) provide information about radio stations that broadcast traffic-related information.

Figure 3-12. Radio-Weather Information sign.
Radio-Traffic Information signs are addressed in Section 2E.56 of the Texas MUTCD.
Radio-Traffic Information signs are designated as D12-1 signs with specifications given in
Standard Highway Signs
. For freeway applications, the larger letter height (10 inches) should be used.The Texas MUTCD provides the following information about the location and content of Radio-Traffic Information signs:
- Only the numerical indication of the radio frequency may be used.
- No more than three frequencies may be shown on each sign. In rest area locations, signs may display a greater number of radio frequencies. However, those signs must not be visible from the main lanes.
- The signs must only display radio stations that broadcast driving-condition information affecting the roadway being traveled during adverse traffic conditions at no more than 15-minute intervals.
Specifically not allowed on the broadcasts of the radio stations displayed on the signs are:
- Identification of commercial names.
- Commercial messages.
Signs for stations that provide traffic information on a seasonal basis must be removed or covered during the off season.