Vehicles and loads

Key messages

  • As far as possible, vehicles should be segregated from other users of the site during vehicle movement or loading/unloading.
  • As far as possible make sure that companies and drivers visiting your site are aware of its layout and any limitations it has before arrival.

The build quality of outdoor traffic routes should be similar to the standards for public highways.

Questions to ask

When you plan a traffic route, your risk assessment should include answers to these questions:

  • How wide is the vehicle?
  • How long is the vehicle?
  • How high are the vehicle and its load?
  • How heavy are the vehicle and its load?
  • What material is the vehicle carrying?
  • What would happen if the load was spilt on site?
  • How easy is it to manoeuvre the vehicle?
  • What is visibility like from the driver's cab?
  • How will you sign the route to tell the driver about height, weight and width restrictions?
  • How will you tell the drivers of unsuitable vehicles that they should not use this route?


The law that requires traffic routes to be wide enough for traffic to circulate freely only applies to routes laid out from 1 January 1993. On traffic routes that existed before then, where it is not practical to widen the road, you should introduce, where necessary:

  • one-way systems;
  • passing places;
  • traffic management systems; and
  • restrictions on parking.

Straight routes used by road-going vehicles should usually be at least 3.5 m wide in each direction, although where speeds are slow, traffic is light, and very wide vehicles or overhanging loads are unlikely, this may be reduced to 3 m.

Routes need to be wide enough to allow for modern materials handling equipment, such as pedestrian-operated pallet handlers and stackers. You might have to decide on traffic routes around the workplace before you use this equipment regularly.

If possible, entrances and gateways should be wide enough to allow two vehicles to pass each other safely.

Routes should also be wide enough to allow vehicles to pass oncoming or parked vehicles safely without leaving the route.


You need to measure and record the vertical clearance under overhead obstructions on all routes.

Your measurement should include any suspended lighting, ventilation or other service features, which are often added after the initial design.

You can then use this information to decide how much overhead space vehicles will need to move around and work safely.

Road vehicles in the UK are usually less than 4.5 m tall. However, tipper vehicles in the raised position can be much taller than this and need more clearance, see Tipping.

Road vehicles including any load they are carrying should not exceed 5.03m (which is the normal minimum clearance under highway bridges in the UK). Beware of situations which may reduce the effective clearance for example if there is a steep ramp running down to an overhead obstruction (for example, when entering a building) the effective height could be reduced especially for longer vehicles. See how this happens.

Clearance for goods vehicles may change with raising or lowering the mid-lift axle, if this is a vehicle feature.

A change to the level of the driving surface could also affect clearance. If a route is resurfaced, you may need to take measurements again.


Bridges and ramps should be able to support the weight of the vehicles (and the loads) that use them. You need to identify and provide clear signage before and on structures with weight restrictions (for example, bridges).


If an accident could result in dangerous mixing of loads, or a load mixing with substances stored or piped on-site, try to find a different and safe route to transport the substance.

Unsuitable vehicles

It is better to restrict vehicles at a place where the driver can choose another route. They should not have to reverse or manoeuvre in a tight space when they find out that they cannot go ahead. Width and height restriction posts can be effective for this.

  • Should site manager specify size when ordering the delivery?
  • Is SatNav sometimes a problem – driver assumes they can go anywhere?

Is this page useful?