Maximum Headroom Available at Arch Bridge Ahead Warning Sign – Diagram 531.1A | Permanent UK Traffic Sign

Maximum Headroom Available at Arch Bridge Ahead Warning Sign – Diagram 531.1A | Permanent UK Traffic Sign

The Maximum Headroom Available at Arch Bridge Ahead Warning Sign – Diagram 531.1A is a critical UK traffic sign used to alert drivers—particularly those operating HGVs, buses, and large plant vehicles—of restricted clearance under arch bridges. Its distinctive shape and format help ensure that over-height vehicles are warned in advance, reducing the risk of bridge strikes and costly road disruptions.

This triangular warning sign conforms fully to TSRGD Diagram 531.1A, BS EN 12899-1, and Chapter 4 of the Traffic Signs Manual. It displays the maximum headroom available—usually in imperial format (feet and inches)—alongside a downward arrow and bridge arch graphic to visually reinforce the low clearance hazard.

Available in all UK-standard triangle sizes (450mm to 1500mm), the sign is constructed using durable aluminium, composite, or self-adhesive vinyl and finished in RA2 or R3B reflective sheeting for superior night and weather visibility. Mounting options include channel rail, plate-only, or adhesive backing, suiting both permanent and temporary installations.

Technical Review

Diagram 531.1A is easily identified by its curved arch bridge graphic and dual-format height display. The black arrow and the clear “feet and inches” measurement ensure clarity for tall vehicle operators. This sign is vital for pre-emptive warning at arch structures, which have variable height profiles and lower clearance on the sides than in the centre.

Why Choose Morelock for Your Diagram 531.1A Sign?

Compliant with TSRGD Diagram 531.1A, BS EN 12899-1, and Chapter 8
Displays height restriction clearly in imperial format
Manufactured in RA2 or R3B reflective finish
Made from aluminium, composite substrate, or sticker backing
Offered in 450mm to 1500mm triangle sizes
Flexible mounting options with fast UK production and delivery

Ideal For:

• Roads passing under historic or arch-shaped bridges
• Routes frequented by lorries, buses, or abnormal loads
• Rail bridge approaches and rural infrastructure
• Sites requiring advance low clearance notification
• Areas where arch bridges may have reduced side height

Summary (Why You Should Buy This Product)

• UK-compliant warning sign for arch bridge clearance hazards
• Clear height indication with imperial measurement
• Durable, reflective, and fully weather-resistant
• Available in all triangle sizes and mounting styles
• Supplied direct from UK manufacturer with quick turnaround

Product Specifications Table

Useful Road Sign Resources

Section	Link & Description
Shop Permanent Signs	Explore all Chapter 8 compliant road signs – reflective and compliant
Standard Triangle Sign Sizes	Choose from 450mm, 600mm, 750mm, 900mm, 1200mm & 1500mm – fast delivery
Permanent Installation Options	Mounting posts, fixings, and installation services across the UK
Get a Road Sign Quote	Request pricing for bulk orders or custom specifications
Government Guidance	Safety at Street Works – Official Code of Practice (PDF) The Highway Code – UK traffic signage rules and standards