Sometimes at roadworks, a line of orange lights turn on and off in sequence, giving an impression of movement.

Question

How is this done as the individual lights don't appear to be connected.

Answer 1

ok i work on the motorways and i install these cones the first load you see they are called the taper to us the light just flash on and off and when you switch one on and by the time you have put the second one on the lights have formed a sequence there is no answer for it . it just happens the reason they flash is because cars and lorrys have a habit of ignoren the signs counting down to the road works and the run in to it so by them flashing it is a second warning so when they go to court they cant say i never seen it . its the most dangerus part of the job installing those cone because i have lost 3 good mates through people ignoren the signs and driveing in to them so take car of road works dangers job

Answer 2

voodoo magic man

Answer 3

they have a photo lens. when the sun starts to set, triggering each one at a later time than the one in front of it