Which color road studs mark the edge of a main carriageway at lay-bys and slip roads?

Which color road studs mark the edge of a main carriageway at lay-bys and slip roads?

• A. Green road studs
• B. Amber road studs
• C. Red road studs
• D. White road studs

Answer: (A)

Green road studs mark the edge of the main carriageway at lay-bys and slip roads. This color cue helps you quickly identify where the main road ends and the slip road or lay-by begins, which is especially useful when joining or leaving a junction or when visibility is limited. Road studs use different colors to convey where the boundaries lie, so this particular green marking is specifically about the boundary between the main road and its access/exit areas. The other colors serve different boundary cues on other parts of the road and aren’t used to indicate the edge of the main carriageway at lay-bys and slip roads.

Green road studs mark the edge of the main carriageway at lay-bys and slip roads. This color cue helps you quickly identify where the main road ends and the slip road or lay-by begins, which is especially useful when joining or leaving a junction or when visibility is limited. Road studs use different colors to convey where the boundaries lie, so this particular green marking is specifically about the boundary between the main road and its access/exit areas. The other colors serve different boundary cues on other parts of the road and aren’t used to indicate the edge of the main carriageway at lay-bys and slip roads.