I've been doing pre-trip walkaround checks for the better part of a decade. Tens of thousands of miles, probably a few thousand walkarounds. And I still find things I nearly miss. Not because I'm careless — I'm genuinely not, not about this — but because tiredness is real, and early mornings are dark, and the human brain gets comfortable with routine.
The items that come back on prohibition notices aren't exotic. They're the same four or five things, on the same components, in the same locations. Knowing that makes the check faster and more useful. You're not inspecting everything equally — you're paying extra attention to the places that actually fail.
Why the walkaround matters beyond the obvious
The obvious reason: you don't want to be driving a defective vehicle. That's real and that's important. But there's a compliance angle too.
Under Section 40A of the Road Traffic Act, it's an offence to use a vehicle in a dangerous condition. That covers drivers, not just operators. If DVSA stops you and finds a defect that a reasonable driver should have identified on a pre-trip check, the prohibition can be directed at the driver as well as — or instead of — the operator. The 'I didn't know' defence doesn't hold if the defect was visible and you should have found it.
The walkaround check is also part of your operator's O-licence obligations. Every vehicle must be subject to a driver defect check before use, and the result must be recorded — even if no defects are found. Operators who can't demonstrate a defect reporting system at a DVSA maintenance investigation are in trouble. Drivers who don't sign off their checks leave operators with no record to produce.
Tyres — where most prohibitions start
Tyres account for a disproportionate share of immediate prohibitions. The most common tyre defects DVSA find at roadside checks, roughly in order:
- Tread depth below the 1mm legal minimum for goods vehicles (the car limit is 1.6mm — HGVs and trailers are different)
- Cuts, bulges, or cord showing on the sidewall
- Wrong tyre type on a given axle (mixing radial and cross-ply)
- Incorrect inflation pressure — visually obvious underinflation on a loaded axle
- Damage to bead or rim that's affecting the tyre's seating
The tread depth check is the one that catches drivers out because HGVs don't have a wear indicator bar in the same obvious way smaller tyres do. You're looking for 1mm across the central three-quarters of the tread width, around the full circumference. A tyre that looks fine on the outside of the tread can be worn down on the inner shoulder where you can't easily see it without crouching.
On a six-axle combination that's 18 tyres plus the spare if you carry one. At 30 seconds per tyre that's nine minutes just on rubber. At a pace where you're actually looking. Most walkarounds I've seen take less than ten minutes total — which tells you something about how thoroughly some drivers are checking tyres.
Lights — the one that's fastest to miss and quickest to fix
All lights need to function. That includes: headlights on main and dip, front and rear fog lights, hazards, brake lights, reverse light, marker lights and side lights on a longer vehicle, and every light on the trailer. A trailer with a blown brake light is an immediate PG9. That's not a conversation you want to be having at 3am at a check site having just come off the M6.
The check you're doing on your own isn't ideal for brake lights because you can't drive and look at the rear simultaneously. What works: park near a reflective surface, a building wall or a trailer side, and apply the brakes while watching the reflection. Or ask a yard colleague to stand behind while you brake. Takes 90 seconds. Worth it.
Marker lights on curtainsiders and flatbeds are the ones most commonly missed. They're small, often mounted at heights that don't catch your eye on a quick pass, and they're usually the last thing fitted by whoever prepared the trailer. Check every amber marker light on both sides. A missing marker light is a defect, but a missing marker light on a loaded trailer at night is the kind of thing that causes accidents before it causes a prohibition notice.
Brakes — you can't fully check them on a walkaround, but you can check some things
You can't check actual brake performance on a walkaround. That needs a rolling test or a brake tester. What you can check:
Airline coupling condition on the trailer — cracked or perished airline rubbers allow air to escape and degrade brake performance. They should be clean, secure, and not showing visible cracking. The gladhands themselves should connect and disconnect cleanly. A coupling that requires excessive force or doesn't seat properly is a defect.
The parking brake. Apply it, try to move the vehicle on flat ground. Shouldn't budge. Under a load this check isn't always possible in a busy depot, but on a clear bit of yard it takes 20 seconds.
Air pressure — if the vehicle has a dash-mounted air pressure gauge, check it once in the cab before pulling out. Spring brakes on most modern HGVs will hold the vehicle if air pressure drops below a safe level, but you want to know the pressure is building correctly before you're on a live road.
Trailer coupling — the one that gets people killed
Fifth wheel or drawbar — depending on your combination — needs to be checked properly. Not a glance, a proper check.
On a fifth wheel: kingpin locked, secondary lock engaged, safety jaw seated. Move the trailer physically if you can — rock it back with a slight application of the artic brakes and watch the fifth wheel. The trailer shouldn't move forward on the fifth wheel plate. If it rocks forward even slightly, the kingpin isn't properly locked.
I've seen a semi-trailer slide off a fifth wheel at a junction. Not fast, not dramatic — just the front of the trailer slowly descending onto the cab roof. The driver had done a walkaround. He hadn't checked the fifth wheel coupling. At 12 mph in a residential street, it caused the kind of damage that ends driving careers and makes newspapers.
Drawbar coupling on a rigid-and-trailer combination: pin, clip, safety chain. All three. The safety chain is not decoration.
The defect book — and why the record matters as much as the check
Found a defect? Report it. Write it in the defect book. The defect book isn't just an administrative formality — it's the record that shows the vehicle was checked and the defect was found before use. If the defect is rectified, the defect book shows that. If the vehicle is taken off the road pending repair, the defect book shows that too.
DVSA at a maintenance investigation will ask to see defect books. They're looking for regularity — a book that shows consistent daily checks with occasional minor defects is convincing evidence of a working system. A defect book with 200 consecutive 'no defects found' entries on a fleet of older vehicles is not convincing. Either the vehicles are miraculously perfect or nobody is really looking.
If you've found a defect and it hasn't been recorded — because you told someone verbally, because the book was in the office, because the yard was busy — that creates a gap. Verbal reporting doesn't produce a trail. The written record does.
The walkaround as a habit, not a procedure
The best walkaround is the one you've done the same way so many times that the sequence is automatic. Same starting point every time. Same direction around the vehicle. Same order of checks. Consistency means you don't skip items because you're in a hurry — you just move faster through a fixed sequence.
Mine takes between 8 and 12 minutes depending on how loaded the trailer is and whether I need to crouch for tyres. Most of that is tyres and lights. The coupling check adds two minutes. I haven't found a significant defect in about 18 months — but I did find a cracked airline last March that would have been a brake problem three hours into a run, and a trailer marker light that was out in a way that wasn't visible until I was underneath the sidelight cluster checking the wiring.
If your operator tracks defect reporting and wants an audit trail beyond a paper book, ShiftOwt logs shift starts and vehicle checks in a format that's searchable and time-stamped — £5.99/month for drivers, operator pricing on request.
Do the walkaround. Write it down. Every time.