- Location
- Welwyn Garden City, Hertfordshire
- Main postcode district
- AL8
- Nearby (straight line)
- Hatfield (3 miles), Hertford (6 miles) and St Albans (6 miles)
- Survey and quote
- Free, with a fixed written quote
Dock traffic lights are red and green signals mounted outside and inside a loading bay to tell the driver and dock staff when it is safe to move or load. Interlocks are control links that stop equipment operating out of sequence, for example preventing the door opening until the trailer is restrained, or the leveller operating until the door is fully open.
Is this right for your site in Welwyn Garden City?
New warehouses in Welwyn Garden City can have lights and interlocks wired in during the electrical fit-out, avoiding retrofit cabling and keeping every bay on one control standard. Loading docks in Welwyn Garden City where drivers wait in their cabs for a hand signal can replace guesswork with a clear red and green light at every bay.
Whether your unit in Welwyn Garden City has one dock or twenty, the survey looks at each bay's existing controls before we quote a fixed price in writing.
Before anything is ordered, we visit your site in Welwyn Garden City for a free survey and then send a written quote with a fixed price. From that point we manage the installation, coordinating delivery, access and any other trades. Fitting is done by specialist installation engineers engaged and managed by us, at times that suit your operation, including out of hours where agreed. You get a tested installation, a demonstration for your team and the manufacturer documentation.
What does HSE guidance say about stopping drivers leaving too early?
HSE guidance (followed by HSENI in Northern Ireland) says there should be safeguards against drivers driving away from a loading bay too early, and it names traffic lights as one of the measures. Vehicle or trailer restraints, and the person in charge keeping keys or paperwork until it is safe, are the others listed in HSE's guide to workplace transport safety (HSG136) and its loading factsheet.
Traffic lights are a signal, not a physical barrier, so they work best as part of a clear procedure or alongside a restraint. Your risk assessment should decide the combination. In Northern Ireland the regulator is HSENI.
Interlocks also touch on door safety law. Under regulation 18 of the Workplace (Health, Safety and Welfare) Regulations 1992, or the Northern Ireland 1993 equivalent, powered doors need suitable and effective features to prevent them trapping anyone. Interlocks must never bypass those features, and door control work should respect BS EN 12453, the standard for safety in use of power-operated doors.
Read more in our guide to preventing drive-away and trailer creep.
How much do dock traffic lights and interlocks cost?
Dock traffic lights and interlocks typically cost £650 to £3,400 per bay, supplied and fitted, excluding VAT. A pair of manually switched LED signals sits at the lower end, while a full interlock panel linking door, leveller, restraint and shelter sits towards the top.
What moves the price:
- Level of control: standalone lights, door-linked lights or a full interlocked sequence.
- Existing control panels: modern door and leveller panels often accept interlocks directly; older panels may need replacing with a combined bay panel.
- Sensors: door position switches, trailer presence sensors and restraint signals each add parts and wiring.
- Cable runs: distances between lights, panels and the power supply.
- Number of bays and timing: repeat bays reduce the cost per bay, while out-of-hours working adds to it.
These are guide budgets. After a free site survey we send a written quote, and that quote is the fixed price. VAT is added at the standard rate.
The same published guide range applies across England; access, out-of-hours working and site conditions are confirmed at the free survey.
What we look at on site
- Working hours, shift patterns and windows for out-of-hours work
- Asbestos register and any other site hazard information
- Forklift and pallet truck loads crossing the leveller platform
- Lighting inside trailers and at the dock face
- Wheel guide positions and yard markings for reversing vehicles
- Wind exposure at the dock, which affects door and shelter choice
Options to discuss
Restraint interlock package
Door, lights and vehicle restraint tied together so the door only opens once the trailer is held and the restraint only releases when loading is finished.
Trailer presence sensors
Sensors that detect a trailer on the bay, used to switch lights, enable the door or trigger an inflatable shelter where no restraint is fitted.
Which rules apply in England?
Sites in Welwyn Garden City fall under the rules for England. Structural changes such as forming a new opening or a dock leveller pit may need Building Regulations approval, and external structures such as loading houses, canopies or new dock approaches can need planning permission from the local planning authority. We check what applies at survey and build any approvals into the plan.
Questions about dock traffic lights and interlocks in Welwyn Garden City
Can you work outside our normal operating hours in Welwyn Garden City?
Yes, by arrangement. Evening, night and weekend working can be planned so the installation causes as little disruption as possible to your loading schedule. Out-of-hours work can affect the price, so mention it at the survey and we will include it in the written quote. The agreed times are confirmed in the programme before the job starts.
What warranty comes with new loading bay equipment?
New equipment comes with the manufacturer's warranty, which varies by product. Our workmanship terms are set out in writing in the quote for your Welwyn Garden City site, so you can see what is covered before you commit. Check the warranty terms for any servicing conditions, and we can quote for planned maintenance once the installation is complete.
Can you work alongside our main contractor on a new build in Welwyn Garden City?
Yes. For new warehouses and fit-outs, we can supply and install the dock package as part of a wider project, working to the main contractor's programme, site rules and permits. We will need drawings, dock levels and the programme, and we coordinate pit details, power supplies and door openings with the relevant trades before installation begins.
Which way round do the inside and outside lights work?
The inside and outside lights always show opposite colours. While a trailer is being loaded, the outside light is red so the driver stays put and the inside light is green so staff can work. When loading is finished and the door is closed, the inside light turns red and the outside light turns green for the driver.
Can you add lights and interlocks across a whole dock in one project?
Yes. A whole-dock project is usually phased bay by bay so most doors stay in use, and every bay ends up on the same control standard. That consistency makes training easier for staff and drivers, and it simplifies servicing because every bay behaves in the same way.
Dock traffic lights and interlocks near Welwyn Garden City
The same survey, quote and repair service is available in towns around Welwyn Garden City, such as Hatfield (3 miles), Hertford (6 miles) and St Albans (6 miles).
Other loading bay services in Welwyn Garden City
Full guide to dock traffic lights and interlocks · Everything we do in Welwyn Garden City
For a written price on loading bay work in Welwyn Garden City, request a quote and include photos of the bay if you can.