STOP takes flashing red, as is traditional (MUTCD 4K.5). Under TFGAP-S, YIELD analogously calls for flashing green.

R1-1	R1-2	R1-5a

Other regulatory signs will take the FBD. Although one might expect the DO NOT ENTER and WRONG WAY signs to be flashing red, the meaning of that signal is precisely this: (1) stop, (2) yield, (3) proceed. Because the R5-1 and R5-1a signs by contrast tell motorists that proceeding is not permitted, they require instead a blue light which merely calls motorists' attention to the sign.

S5-1	R14-3	R5-1	R5-1a

While 300 mm is the most likely diameter for FBDs, a larger size such as 450 mm might be good for overhead signs such as the R3-14, and a smaller size such as 200 mm for pedestrian signs.

R11-2	R3-14	R9-2