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 Northamptonshire?
If a site in Northamptonshire has had door panels damaged by levellers raised too early, a leveller-to-door interlock is a straightforward fix to consider. Food and chilled operations around Northamptonshire with inflatable shelters often add interlocks so the shelter only inflates once a trailer is docked and restrained.
Older docks in Northamptonshire with separate door and leveller controls can be brought into a proper sequence by adding interlocks that stop equipment working out of order.
Before anything is ordered, we visit your site in Northamptonshire 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.
Can traffic lights and interlocks be added to older loading bays?
Yes, traffic lights and interlocks can be added to most older loading bays, although some need new control panels before the interlocks can work.
- Manual doors: a door position switch can confirm the door is fully open or closed, which lets lights and leveller interlocks work even without a motor.
- Older powered doors and levellers: basic control boxes may not have connections for interlocks, so a combined bay panel can replace separate controls.
- Mixed equipment: doors and levellers from different suppliers can usually be brought under one interlock panel, so every bay works the same way.
Interlocks cannot make faulty equipment safe. If a door or leveller has a defect, it should be repaired before interlocks are added, and the survey will flag anything we find. Upgrading lights and interlocks at the same time as replacing a door or leveller is often the most economical moment to do it.
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 Northamptonshire
Looking for dock traffic lights and interlocks in a specific part of Northamptonshire? Start with the nearest town on this list.
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 England mean for the work?
Sites in Northamptonshire 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
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 Northamptonshire 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 Northamptonshire?
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.
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.
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.
Other services in Northamptonshire
Full guide to dock traffic lights and interlocks · All loading bay services in Northamptonshire