Reflective amber studs on a motorway are found along the right-hand edge of the main carriageway next to the central reservation (the barrier or area dividing traffic going in opposite directions).

Where they are on the road

  • They run between the offside (right) lane and the central reservation on dual carriageways and motorways.
  • In multi‑lane motorways, they mark the boundary between the outermost lane and the central reservation so you do not drift towards oncoming traffic.
  • They appear continuously on straight sections, curves, and through areas like tunnels or fog‑prone stretches where visibility is reduced.

Why amber studs are used

  • They help drivers judge their position at night or in poor weather when painted lines are harder to see.
  • The amber colour clearly contrasts with other stud colours: white for lane separation, red for the left-hand edge, and green for slip roads or lay-bys.
  • By clearly marking the edge next to the central reservation, they reduce the risk of vehicles drifting too close to the barrier or into opposing traffic.

Information gathered from public forums or data available on the internet and portrayed here.