Dash cams for HGV drivers: where it can go, and the rules for a work vehicle
A dash cam is a good witness. It's also a thing stuck to the windscreen of a vehicle that gets inspected, and a camera in a work vehicle brings its own rules. Both are easy to get right if you know them before you fit it.
Where it can go on the windscreen
The law behind this is regulation 30 of the Construction and Use Regulations: the driver must have a full view of the road and traffic ahead. DVSA's guidance on windscreen obscuration splits the wiped area of the screen into two zones. Zone A is a vertical band centred on the steering wheel, 350mm wide on a vehicle over 3.5 tonnes. Anything in it, a sticker, a sat nav or a camera, must not encroach more than 10mm. Zone B is the rest of the wiped area, and the limit there is 40mm. Original vehicle design features and driver aids, such as sun visors, are allowed.
The daily walkaround guidance for HGVs is blunter: "As a general rule, there should be nothing in the swept area of the windscreen wipers." So the place for a camera is outside the wiped area, high on the screen. If the only spot the mount reaches is inside the sweep, keep it to the top edge and within the encroachment limits above, and never in the band in front of the driver.
The same applies to a phone doing the job: gov.uk's rule on devices while driving allows a windscreen mount, but "the device must not block your view of the road and traffic ahead", and you can get 3 penalty points if you don't have a full view of the road.
If it's a work vehicle
The ICO's guidance for small businesses is written for the business that runs the vehicle: if a work vehicle has a dash cam, the business needs to register with the ICO and pay a data protection fee (most small businesses pay £52 a year). It also expects people to be told recording is happening, which "can be as easy as putting a sticker on your vehicle"; audio to be switched off by default and used only in exceptional circumstances; and the camera to be off during personal journeys in a business vehicle.
If the truck isn't yours, ask the operator before you fit a camera. They may already have a policy, and the rules above land on them, not on you.
What to look for
The mount. Can it sit outside the wiped area on your screen? Measure where it can go before you buy, not after.
The power. Check the supply the camera takes against the vehicle it's going in. A hardwire kit for parking mode is a job for whoever looks after the vehicle's electrics, and on a work vehicle that means asking first.
Audio off. If it records sound, make sure it can be turned off and stays off. The ICO's line on audio is above.
What a camera doesn't change
A dash cam doesn't make a windscreen chip legal or a mirror less obscured. The walkaround still starts with the view from the driver's seat: the windscreen not cracked, scratched or discoloured, the mirrors in place and not obscured, the wipers and washers working. What a walkaround check must record covers what goes on the sheet.
Windscreen zones and limits are from DVSA's guidance View to the front and windscreen obscuration (regulation 30, Road Vehicles (Construction and Use) Regulations 1986); the swept-area line and the driver's-seat checks are from gov.uk's HGV daily walkaround guidance; the work-vehicle rules are from the ICO's Dashcams and UK GDPR: what small businesses need to know; all read September 2026.
Guidance only, not legal advice. Always check against current DVSA and ICO guidance. Roadworthy is an independent tool provider and is not affiliated with, or endorsed by, DVSA or the ICO.