Dave Harford on X: "I often go on about the blue & white marker posts like below on motorways used to identify your location. But what if you can't see any? Did
Verge Marker Posts | Highway Supplies
CMPG on X: "Do you know what motorway marker posts mean? You do now! http://t.co/Zxd90KYA4q" / X
Motorway marker post showing direction to nearest emergency phone Stock Photo - Alamy