Warn them with radar.
Fors
C
C
Speed Measurement Laboratories, Inc., TX, USA.
D000063:Accidents, Traffic / Q000517:prevention & control; D000552:Ambulances / Q000592:standards*; D001334:Automobile Driving / Q000592:standards*; D017046:Cost Savings; D011825:Radar; D017751:Safety Management / Q000379:methods*; D014481:United States