The back of a truck at night is a wall of dark metal until the markings make it legible: the red-and-yellow chevron boards that tell a following driver, instantly and at distance, this is a large vehicle, this is its width, keep back. Those boards are not decoration or fleet branding space - they are a legal requirement with defined thresholds, and their absence or deterioration is a defect examiners know exactly how to find.
The official guidance - the Highway Code’s vehicle markings section, covering large goods vehicle rear markings - sets the trigger weights plainly: motor vehicles over 7,500 kilograms maximum gross weight and trailers over 3,500 kilograms maximum gross weight must carry the prescribed rear markings. The same guidance covers the wider marking family: hazard warning plates, projection markers and the other markings that make loads and vehicles readable.
The requirement’s logic is conspicuity at the most dangerous interface: the closing speed between a car at motorway pace and a heavy vehicle is where fatal underrun collisions live, and the reflective rear marking is engineered to be seen in headlights far earlier than the vehicle’s structure resolves. The chevron pattern, the colours, the placement at the rear extremities - all specified so the signal is uniform: every compliant truck reads the same way to every driver, at night, in rain, at speed.
The failures are as patterned as the boards. Threshold blindness on trailers: the 3,500kg trailer trigger is lower than operators expect, and the fleet’s heavier trailers cross it while nobody updated the marking check. Deterioration: the markings are reflective material exposed to pressure washers, road salt and abrasion - faded, peeling or delaminated boards fail the requirement as surely as missing ones, and the decline is gradual enough to miss without a condition check. Obscuration: loads, tail lifts in the raised position, and aftermarket equipment fitted across the marked area - the marking is present but hidden, which in law is much the same as absent. And the bodybuilder gap: new bodies, beavertails and conversions delivered without the markings fitted, where the fleet assumed the bodybuilder fitted them and the bodybuilder assumed the fleet would.
The test and roadside reality mirrors the maintenance one: markings are a named part of the annual test’s vehicle inspection and a standard roadside check item, precisely because they are both safety-critical and easy to let slide.
Rear markings earn a line in three places in the maintenance system. The walkaround: boards present, secure, legible - a look, not a measurement, but a deliberate one. The safety inspection: a condition check that looks for the peeling and fading the walkaround tolerates too long, with replacement ordered before the material dies completely. And the acquisition process: every new trailer, body or conversion checked for the correct markings at delivery, against the weight thresholds, before it works its first day - because the cheapest time to fit a marking is before the vehicle enters service, and the most expensive is after a prohibition.
Replacement boards are cheap, standardised and quick to fit; the only expensive version of this compliance item is the one discovered by an examiner.
Rear reflective markings are mandatory above defined thresholds - 7,500kg for motor vehicles, 3,500kg for trailers - with the wider family of hazard plates and projection markers alongside. Check them on the walkaround, grade their condition at inspection, verify them at delivery of any new body or trailer. The back of the truck is the most-read sign on the road; keep it saying the right thing.
The chevron boards are the best-known member of a family that scales with the vehicle’s challenge to other road users. Long vehicles carry the length markers along the side and rear; slow vehicles - the agricultural and works vehicles that share the road at a fraction of traffic speed - carry their own rear marking and the reflective triangle that has warned of slow traffic for generations; and vehicles with projections carry the markers that advertise the overhang before a following driver meets it. The common logic is honesty about the vehicle’s presence: the law requires the vehicle to declare its size, its speed and its extremities in the visual language every driver reads, day and night.
Markings are a procurement decision as much as a maintenance one. Specification on new builds should name the marking requirement explicitly - boards fitted to the prescribed standard, positioned per the rules, of material grade that survives the wash bay - and the delivery inspection should accept the vehicle only when the markings are present and correct. Operators who write the requirement into the body order never have the delivery-day argument; operators who assume it get to have it instead, with the vehicle already off the road it was bought to work.
Keep the records with the rest of the maintenance file: marking condition noted at inspection, replacements dated, delivery checks filed. The file is what turns a prohibition conversation into a demonstration of a working system.