“You are on a motorway in fog. The left-hand edge of the motorway can be identified by reflective studs?

Question

what colour are they?

Answer 1

Red if you're in the UK.

"111: Reflective road studs may be used with white lines.

* White studs mark the lanes or the middle of the road.
* Red studs mark the left edge of the road.
* Amber studs mark the central reservation of a dual carriageway or motorway.
* Green studs mark the edge of the main carriageway at lay-bys, side roads and slip roads."

Answer 2

Those studs are 'cat's eyes' is a safety device - Originally, these were glass spheres about 1 cm in diameter in a brass holder -built into a sturdy housing, capable of surviving as vehicles pass over it. They are placed along road markings, as they serve to highlight these markings at night, fog, or low lighting conditions.

Cat's eyes were invented in 1933 by Percy Shaw of Halifax. The name "cat's eye" comes from Shaw's inspiration: the light reflecting from the eyes of a cat.

A key feature of the cat's eyes was being fixed into a flexible rubber dome support which buckled under the weight of vehicles, allowing the cat's eyes to sink below the road surface. A fixed rubber wiper passed over the front surface of the reflector as it sank below the surface of the road, thus cleaning the reflector. Other reflectors that did not have this feature rapidly lost their effectiveness as they became dirty.


They became popular in Britain during World War II, in the era of blackouts. The Government realised that drivers needed to see where they were going, even in the midst of a blackout. Cat's eyes use a system where the light is reflected from the car's headlights, thus allowing a limited amount of light. There are now some self-illuminated versions, either wired to a power supply or using solar power. These increase visibility range. An additional benefit of cat's eyes is the characteristic thunk sound made when driving over the device, warning a driver that they have started to leave their lane.

With the invention of mulit-lane roads, they have been developed further, so now in Britain, white cat's eyes are used for the centre of a road, lane markings, or soft traffic islands. Red cat's eyes are placed along the hard shoulder of a motorway, and orange cat's eyes are placed along the edge of the central reservation. Green cat's eyes denote joining or leaving slip roads at junctions, and blue cat's eyes are used for police slip roads.

Answer 3

They are red on the left side, white in between the lanes, amber on the right side (by central reservation), green to separate the deacceleration and acceleration lanes (slip roads - where you drive off and on) and blue on the left side where there is a police layby.

Answer 4

red on a slipway, green otherwise

Answer 5

Red unless you are blind

Answer 6

green I think....

Answer 7

and the question is what

Answer 8

Green I think ............