By EWAN KENNEDY
29 December 2008

Yet another unbiased and scientifically correct study has come out on the subject of causes of car crashes. And yet again excessive speed has been shown as being the reason for only a small percentage of crashes.

The report from the USA was carried out by the highly respected National Highway Traffic Safety Administration (NHTSA). It investigated 5471 injury crashes that took place across the States between July 3, 2005 and December 31, 2007.

Researchers went to the site of the crashes as quickly as possibly, frequently getting there before the scenes were cleared. This allowed a close look at the physical evidence, as well as direct interviews with witnesses and others involved in the incident. NHTSA then evaluated the data to determine the factors most responsible for the collision.

Next, NHTSA determined the critical reason by a thorough evaluation of all the potential problems related to errors attributable to the driver, the condition of the vehicle, failure of vehicle systems, adverse environmental conditions, and roadway design.

The critical pre-crash event refers to the action or the event that puts a vehicle on the course that makes the collision unavoidable, given reasonable driving skills and vehicle handling of the driver.

Overall, vehicles ‘traveling too fast for conditions’ accounted for only five percent of the critical pre-crash events. Even when you consider only the driver-fault part of the equation, and ignore road and weather conditions, car state and other factors, that number still only rises to about 13 per cent.

More significant factors of crashes included 22 percent driving off the edge of a road and 11 percent who caused their car to wander over the road’s centre line.

When driver error was the primary cause of a crash, researchers went further to identify the critical reason behind that error. Distraction and not paying attention to the road accounted for 41 percent of the errors.

Ten per cent of errors were attributed to drivers lacking proper driving skills and either freezing up or overcompensating on the steering wheel as they panicked. Eight per cent were asleep at the wheel, some unfortunates got a double whammy by suffering a heart attack, others were otherwise incapacitated.

In the NHTSA report, ‘too fast for conditions’ does not mean exceeding the speed limit. There can be times when the correct speed is below the speed limit. That’s something every experienced driver is aware of, but which can be a trap for young players brainwashed into thinking that staying below the limit is all that matters when driving.

The NHTSA report is a highly detailed one and I have no reason to believe these causes of crashes in the USA vary more than marginally from the same incidents in Australian conditions.

I have said it before but have no hesitation in saying it again. Drivers not paying proper attention or being distracted for whatever reason are the number one reason for road deaths in Australia. Exceeding the speed limit only plays a minor part. Yet our governments harp on endlessly about obeying speed limits. Perhaps if they concentrated on the other 95 per cent of the reasons for car crashes we would see an even greater decrease in the number of deaths on Australian roads.

A full copy of the NHTSA report, which runs to about 47 pages and covers many facets, is available from:
http://www.nhtsa.dot.gov/. Select “Newest Studies And Reports” then “NMVCCS Report to Congress (PDF)(DOT-HS-811-059”

ewan@marque.com.au