Crash scanner cuts delays

In recent years, I seldom travel major motorways such as the M4 without encountering a tailback from a shunt, which makes journey-planning a challenge. Last year there were more than 18,000 full or partial motorway closures lasting a total of more than 20,000 hours. Even minor prangs cause big tailbacks, but if it's more serious, the police have to investigate - and that means closing at least part of the highway, sometimes for hours.

Nothing that might prove vital later can be overlooked even if, at the scene, it looks unimportant. Unfortunately, it means you'll be stuck there for hours.

Until now that is, thanks to new equipment that is transforming the way police gather evidence at crash scenes.

One example, developed by Leica Geosystems, is the ScanStation C10 which uses lasers and advanced 3D technology to "capture" the entire accident scene, including apparently insignificant shards of glass and tyre marks, within just minutes.

According to police the new equipment, costing up to £100,000, reduces the time needed to analyse crash scenes by around 40 per cent, meaning average savings of 39 minutes on location. Even complex crash scenes can be "captured" in just 45 minutes by the compact tripod-mounted device, which is excellent news for motorists on a schedule. Previously, accident investigators had to laboriously record evidence at the scene, using digital equipment or, before that, string and tape measures.

Now, however, the new technology "freezes" the scene in 3D with a highly detailed 360-degree digital picture of evidence such as impact zones, skid marks, debris trails, positions of vehicles, and even body parts.

It emits 50,000 laser beams a second and rotates through 360 degrees, detecting beams reflected from objects up to 300 yards away and instantly capturing the data.

The reflections enable it to calculate the size, location and colour of objects and, to be thorough, investigators place the ScanStation at several different locations around the crash scene, with the device "stitching" the images together, allowing officers to examine the area in its entirety, close-up on computer screens, back at HQ.

"Investigators can recreate and 'walk' through the scene once they are back in the office," says Tim Badley, 3D laser scanning sales manager for Leica. "And you can view the accident scene from whichever angle you wish."

This leap forward in technology means the courts get a clearer picture of what happened in the run-up to an accident than ever before.

Geoff Chambers, manager of the Forensic Collision Investigations Unit for the Thames Valley and Hampshire Police, explains: "This is a massive step forward that is going to make a huge difference for motorists. When we investigate a collision scene it is a crime scene until we know otherwise. Before, we had to take photos. With this we scan it and virtually carry the entire collision scene back to the office with us."

Now, following an 18-month trial by the Highways Agency, England's 40 police forces have been allocated an additional £3 million to ensure that each one can purchase 3D equipment to help keep its own roads moving too.

Police will still need to carry out visual searches of crash scenes: vehicles might reveal that a mobile phone was in use, or the presence of drugs or alcohol. And crash scenes must always be made safe before motorists can file past the wreckage.

But as Badley points out: "Even in cases where using the new technology only saves fives minutes, if you add up all the huge inconvenience caused to each individual stuck in that jam, it makes an important difference."