A hi-tech, low-cost system to prevent bridge strikes has been created by researchers at the University of Cambridge’s Centre for Smart Infrastructure.
The new system, being developed in conjunction with London Underground, involves placing a camera ahead of a low bridge and using computer vision to detect oversize vehicles before sounding a warning message and audible siren to alert the driver.
Should a driver ignore a warning and hit a bridge, an accelerometer on the bridge would establish the magnitude of the damage and send a report to the infrastructure owner.
In the example of a rail bridge being hit at force, a decision could be taken instantaneously to halt trains. Additionally the camera would record the number plate on the vehicle and send it to the owner of the bridge allowing it to charge the vehicle owner for the damage caused.
Ioannis Brilakis, Laing O’Rourke reader in construction engineering at the university, said the cost of laser-based anti bridge strike systems could be up to £150,000 in each direction, and that the proposed system could cut that to just £15,000 each way.
He said the bulk of the cost for laser-based systems often came in the infrastructure needed to mount sensors before the bridge. However, in the camera-led alternative proposed, existing structures could be used and the camera calibrated accordingly.
There are about 10,000 railway bridges over roads in the UK, and 3,400 are considered to be at risk due to a low clearance height, with a tall truck hitting a bridge every four and a half hours. Brilakis said the cost per bridge strike could be up to £25,000.
“Bridge collisions involving over-height vehicles lead to traffic delays, congestion and, in extreme cases, can derail trains and cause bridges to collapse,” said Brilakis.
“What we have created is an autonomous system that bridge owners can use to reduce the number of strikes and charge offenders when damage is caused. The new system matches the performance of its predecessors at a fraction of the cost.”