usually a sign that tells you about it. Like a 'curve warning'. Or a 'right of way' sign. 'Narrow bridge'. 'Signals ahead'. 'Do not enter'. 'No passing', and many others. Crow: 'All nude girls!' Servo: 'Whites only'. [Close-up of woman driving, having difficulty with a map] Patrolman: Here's another problem on the roads that we officers face all too often... Mike: Women drivers! [everyone chuckles condescendingly] Patrolman: ...the entering car that fails to yield the right