In plain English
Blue rectangles with road numbers like M62 are motorway directions. The moment signs turn blue, you're in motorway world — motorway rules and motorway speeds apply.
Where you'll see it
On motorways and on approach roads that lead to them.
The common trap
Forgetting the colour code: blue = motorway, green = primary route, white = local. The colour tells you the road type before you read a word.
Memory anchor
Blue like the open sky on a long journey — motorway colours.
Quick check