Variable message sign
A gantry structure spanning the road with electronic signals over each lane and a large MS4 message sign on the left.
A 50mph speed limit is shown over all lanes, except the left lane which has a red X. The message "lane closure" is shown.
Somewhere here, just south of junction 23, we pass some sliproads that lead to a maintenance compound. It was supposed to be a service area called Haydock Park, but the services were never built.