Suppose I’m driving down the road.

It’s a built-up area and the road signage clearly indicates that the designated speed limit is 50 km/h.

I’m late, I’m in a hurry, I’m supposed to be somewhere. Nonetheless, I try to keep to the speed limit. Glancing down at my speedometer, I see that the reading is steady on 50 km/h.

I maintain my current speed. Well and good.

Then, looking up, I see I’m approaching one of those radar speed signs that displays the speed of the immediately oncoming vehicle, mine. It reads 80 km/h and flashes me to SLOW DOWN.

How fast am I really going?

Should I slow down? Or should I keep calm and carry on?