A lorry strike on an M20 pedestrian bridge over the Bank Holiday weekend has raised concerns around network management.
A digger being transported on a lorry travelling towards London struck the pedestrian bridge on Saturday 27 August at 12.05pm resulting in a partial collapse.
No-one was seriously injured in the accident, although a motorcyclist suffered broken ribs in throwing himself off his bike to avoid hitting the collapsing bridge deck. Part of the bridge also fell on to a second lorry, the driver of which was treated for shock at the scene.
The motorway was then closed in both directions between junctions 1 and 4, causing traffic chaos.
Kent Police’s Serious Collision Investigation Unit are conducting an investigation into the accident and the RAC Foundation has led calls for Highways England to do more to ensure lorry drivers are aware of the risk of bridge strikes.
“The M20 crash raises many questions, chief amongst them: is enough being done to ensure lorry drivers understand the limitations of the network?” said a spokesman.
“Guidance on the Highways England website refers extensively to the weight, width and length of abnormal loads but there is less said about height considerations which is arguably the bigger area of concern,” he added.
The RAC said that Highways England should look to emulate Network Rail which takes the risks far more seriously.
“Network Rail closely records the 1,500 or so annual vehicle strikes on bridges which carry its tracks but is there such a systematic approach to what happens elsewhere on the transport network?” it asked.
The RAC added that the M20 incident was not a new phenomenon. Two years ago a Department for Transport report recognised that: ”Structures such as footbridges or pipe gantries are particularly vulnerable where drivers are careless about the height of their loads and, as a result of such carelessness; several have been dislodged or brought down over the years across the country.”
Highways England declined to comment on the cause of the accident, citing the ongoing Police investigation.
Highways England contractors removed the collapsed span on Sunday and the remaining elevated structure was inspected and declared safe before the motorway was reopened. An operation to remove it will begin in the coming weeks.
Engineers said that the fault appeared to lie with the lorry driver. Bridges on the motorway network have a minimum clearance of 5.7m, according to Highways England. This expands across the carriageway to include the hard shoulder.
”The M20 footbridge was sloping quite heavily - so, the lowest point is definitely at the location where it was indeed struck. I’d be more than reasonably sure that the culprit was the low-loader/digger being too high, rather than the bridge being too low,” independent bridge designer Simon Bourne told New Civil Engineer.
M20 bridge strike
Source: NPAS Red Hill
There were suggestions that work may have been ongoing on the bridge. A Varley and Gulliver branded Combisafe system was in place when the collision took place.
But Varley and Gulliver confirmed to New Civil Engineer that it was not working on the bridge when the collision took place, and that the product – after an initial lease period – was sold at least a year and half ago to the then contractor on the road.