Route planning is where an abnormal load movement is won or lost. The vehicle and trailer can be perfect, but if the route hides a weak bridge, a low arch or a tight roundabout, the whole job stalls. Good planning is methodical, starts early and treats every structure and pinch point on the road as something to be checked rather than assumed.
Why a normal route rarely works
Standard sat-nav routing is built for ordinary vehicles. An abnormal load may be over-height, over-width, over-length or far heavier than the 44-tonne limit that defines a normal HGV, and any one of those dimensions can rule out a road that looks fine on a map. The planner’s job is to find a route that the load physically fits and that every structure along it can legally carry.
The big four hazards
Bridges and weight limits
Bridges are the single biggest constraint on heavy loads. Each structure has an assessed capacity, and routes for heavier movements must be checked with the relevant bridge authorities, who may require notice and an indemnity. Some bridges have firm gross-weight limits that simply cannot be exceeded, which can force a long detour.
Low bridges and headroom
Over-height loads live in fear of low bridges. Every railway and canal bridge on the route has to be checked against the travelling height of the load, with a safety margin. Bridge strikes are costly, dangerous and disruptive, so an over-height movement is routed specifically to keep clear headroom throughout.
Width and swept paths
Wide loads need room not just on the straight but through bends, roundabouts and junctions, where a long trailer sweeps a much wider path than its physical width. Pinch points such as central islands, build-outs, parked cars and street furniture all have to be assessed.
Timing and traffic
When a load moves is as important as where. Heavy and wide movements are often scheduled overnight or outside peak hours to reduce congestion, and some routes carry curfews or specific time windows agreed with the police and highway authorities.
ESDAL and the notification process
ESDAL, the Electronic Service Delivery for Abnormal Loads, is the system used to plot a route and notify the police, highway authorities and bridge owners in one coordinated process. Notice periods scale with the load:
- Loads up to 80,000kg generally require two clear working days’ notice to highway and bridge authorities
- Loads over 80,000kg up to 150,000kg require notice to the police plus around five clear days with indemnity to road and bridge authorities
- The very heaviest movements, over 150,000kg, need a special order applied for weeks in advance
A sensible planning sequence
- Confirm the exact travelling dimensions and weight, including any overhang
- Identify origin and destination access constraints first, they often dictate everything else
- Plot candidate routes and check every bridge, low structure and pinch point
- Submit notifications through ESDAL and act on the responses from authorities
- Agree timing, escorts and any conditions before the movement day
Surveying the route in advance
For the most demanding movements, planning on paper is not enough and a physical route survey is carried out. Someone drives the proposed route in advance, checking the things a map cannot show: the real height of a bridge soffit, whether a roundabout can actually be negotiated, where parked cars habitually narrow a street, and whether overhead cables or low signage will foul an over-height load. Photographs and notes from the survey feed back into the plan, and sometimes reveal that the obvious route is impossible and a longer one is needed.
Access at the origin and destination deserves the same scrutiny. It is no good getting a load to the gate if it cannot turn into the yard, reach the unloading point or be craned off where it needs to go. Experienced planners check the first and last hundred metres as carefully as the motorway miles in between, because that is where movements most often come unstuck. Good local knowledge of the road network, particularly across the Midlands, turns this from guesswork into a reliable, repeatable process.
Abnormal load planning rewards experience and local route knowledge. Northampton Road Haulage plans and notifies abnormal movements across the Midlands and nationwide. Call our Northampton team on 01604 385213 for a no-obligation quote and honest advice on the right approach for your load.