Definition of photo-radar in US English:

photo-radar

noun

North American
  • A computer-operated traffic control system employing radar to measure the speed of vehicles, a camera being triggered to photograph those exceeding a specified limit.

Origin

1980s; earliest use found in The Los Angeles Times. From photo- + radar.

Pronunciation

photo-radar

/ˌfəʊtəʊˈreɪdɑː/