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.
Why do sites in Dumfries and Galloway choose this?
Food and chilled operations around Dumfries and Galloway with inflatable shelters often add interlocks so the shelter only inflates once a trailer is docked and restrained. New warehouses in Dumfries and Galloway can have lights and interlocks wired in during the electrical fit-out, avoiding retrofit cabling and keeping every bay on one control standard.
Older docks in Dumfries and Galloway with separate door and leveller controls can be brought into a proper sequence by adding interlocks that stop equipment working out of order.
Any project involving dock traffic lights and interlocks at a working site in Dumfries and Galloway takes planning. We survey free of charge, quote a fixed price in writing, and then agree a programme that keeps as much of the dock running as possible. Specialist installation engineers carry out the work under our management, out of hours if that suits you better. On completion we test each item, show your team how it operates and leave the documentation with you.
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.
Towns we cover in Dumfries and Galloway
Each of the following towns in Dumfries and Galloway has its own page on dock traffic lights and interlocks, covering how we work and what to send us.
Budget range for supply and fit. The written quote after a free survey is the fixed price. All guide prices.
What do the rules in Scotland mean for the work?
In Scotland, building work such as forming a new opening or a dock leveller pit may need a building warrant from the local authority before it starts. For sites in Dumfries and Galloway, external structures such as loading houses or canopies may also need planning permission from the council. We check what applies at survey and factor any approvals into the programme.
Questions
Do you remove and dispose of the old equipment?
Yes, where it is part of the scope. When we replace doors, levellers, shelters or seals at a site in Dumfries and Galloway, removal and disposal of the old equipment can be included and is itemised in the quote, so it is clear what is covered. If anything should be kept, such as a frame or motor that is still serviceable, we agree that at survey.
Which building and safety rules apply to a site in Dumfries and Galloway?
It depends on which UK nation the site is in. England and Wales use Building Regulations approval, Scotland uses building warrants and Northern Ireland uses building control approval from the council. Workplace safety is regulated by HSE in Great Britain and HSENI in Northern Ireland, and energy rules differ between nations. For your site in Dumfries and Galloway, we check what applies at survey and design to it.
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.
Do traffic lights and interlocks need maintenance?
Yes. Lights, sensors and interlocks should be checked at each planned service visit, including testing the full sequence and confirming that steps attempted out of order are blocked. As part of the dock equipment they fall under PUWER, which requires work equipment to be maintained in a safe condition.
Other services in Dumfries and Galloway
Full guide to dock traffic lights and interlocks · All loading bay services in Dumfries and Galloway