Oregon OSHA Health and Safety


February 2016

Behind the wheel in Oregon

What you should know about crashes, accidents, and the Haddon Matrix

If you happen to be driving the Interstate 5 corridor in Portland between 5 and 6 p.m. on a Friday, and you're feeling a bit tense, there's a good reason for it. It's a peak time for vehicle encounters of the unwelcome kind: crashes. But crashes happen anytime and the numbers add up. In 2014, there were 51,245 motor vehicle crashes in Oregon, according to the most recent data available from the Oregon Department of Transportation. Those crashes affected 93,526 drivers, 11,954 passengers, 1,074 motorcycle riders, 1,010 cyclists, 927 pedestrians, and 107 occupants of parked vehicles. That's 108,598 people - roughly the entire population of Gresham.

However, when you factor in all the miles that drivers, passengers, pedestrians, cyclists, and motorcycle riders travel on Oregon roads every second of every day, motor vehicle crashes are actually rare events. Consider that there were 1.45 crashes per million vehicle miles traveled on "non-freeway" highways and 0.47 crashes per million vehicle miles traveled on Oregon interstate freeways in 2013.

If vehicle crashes are rare events, why aren't they called accidents? They are, and that's a problem for many safety professionals who say that an accident is a convenient category for describing anything unfortunate that happens by chance. Most vehicle crashes do not happen by chance, however; they can be expected to happen even if the time, place, and precise circumstances cannot be foreseen. The word "accident" has never been graced with a clear working definition, which makes it too easy for people to claim that the accidents that happen to them – or their employees – are beyond their control.

Dr. William Haddon Jr. was not fond of the word accident either. He asked people at his meetings to put a 10-cent fine in a penalty jar each time they used the word. Haddon happened to be an early crusader for safer automobiles and was the first director of the National Highway Traffic Safety Administration. Haddon proposed that people, vehicles, and the environment were all critical to the study of motor vehicle safety. The idea may seem obvious now, but it was Haddon who built these factors into an analytical framework. In 1970, he used the framework to analyze vehicle crashes, and it became known as the Haddon Matrix.

In a classic 1979 study (the study's title included the word "accidents" rather than "crashes") conducted at Indiana University's Institute for Research in Public Safety, J.R. Treat and other researchers used elements of the Haddon Matrix to evaluate the causes of vehicle crashes among Indiana drivers. Why was the study important? The study found that human factors caused 93 percent of the crashes; environmental factors caused 12 percent to 34 percent of the crashes; and vehicle factors caused 4 percent to 13 percent of the crashes. And those percentages are still valid today.

In theory, if you can precisely control the human, environmental, and vehicle factors, you can eliminate motor vehicle crashes. In the future, autonomous vehicles In theory, if you can precisely control the human, environmental, and vehicle factors, you can eliminate motor vehicle crashes. In the future, NIOSH Center for Motor Vehicle Safety is using in its strategic plan for 2014-2018 to protect workers from vehicle crashes. The center is also evaluating employers' motor vehicle policies and procedures in developing the plan.

Infographic: worker injuries and deaths involving moving motor vehicles
Infographic by Ron Conrad

Did you know?

Oregon motor vehicle quick facts

Top three driver errors:

  1. Failure to avoid stopped or parked vehicle ahead
  2. Failure to yield right-of-way
  3. Ran off road

Top three pedestrian errors:

  1. Crossing between intersections
  2. Disregarded traffic signal
  3. Failure to yield right-of-way

Top three bicyclist errors:

  1. Failed to yield right-of-way
  2. Disregarded traffic signal
  3. Bicycling on shoulder facing highway

Source: Oregon Department of Transportation, 2014 Quick Facts

Crashes involving Oregon workers

The NIOSH Center for Motor Vehicle Safety defines work-related crashes as those that occur on or off public roadways when workers are on the job and events in which a pedestrian worker is struck by a motor vehicle. In 2014, there were 900 Oregon workers injured in crashes that met the definition.

Within those work-related crashes are crashes reported to Oregon OSHA. (As Oregon employersknow, you must report work-related fatalities and catastrophes to Oregon OSHA within eight hours, and all inpatient hospitalizations, amputations or avulsions, and loss of an eye to Oregon OSHA within 24 hours. The requirement includes motor vehicle crashes.) Only a handful of crash-related casualties filter through to Oregon OSHA, but the injuries are severe. The number was 16 in 2015.

The infographic shows when they happened. Human factors, environmental factors, and vehicle factors determined how they happened. Here is a summary.

Workers struck by vehicles: 10 cases

Work zone crashes – three cases

What happened? In each case, an intoxicated driver crashed into a work zone and struck a worker.

Struck by a vehicle, backing up – four cases

What happened? These four cases had just one thing in common: the vehicle was backing up.

  • A dump truck backed up and ran over a worker at a construction site; employees were following all required safety procedures. It is not known why the victim walked behind the truck.
  • A worker was found dead under the rear tire of a semi-truck trailer. He may have been trying to fix an air leak in the brakes when the truck began to roll backward. The case is still under investigation.
  • An angry driver at a gas station backed up his pickup truck at high speed and struck an attendant.
  • A worker was connecting his truck to a trailer at a busy package distribution center when he was struck by another truck backing up its trailer. Better communication between drivers and more space between vehicles may have prevented the incident.

Struck by vehicle, going forward – three cases

What happened? In two cases, the drivers were sitting partially in their vehicles trying to move them slightly when their foot slipped and the vehicles lunged forward. In the third case, a car wash attendant walked in front of a car when it suddenly lunged forward.

Vehicle crashes: six cases

What happened? The fiery truck crash near the St. John's Bridge in Portland on Dec. 13 marked the sixth vehicle crash reported to Oregon OSHA in 2015. It was also the third fatal crash reported to the agency. The other two fatal crashes involved vehicles crossing centerlines. In one of those incidents, a school bus driver died in May when her bus crossed over the centerline and collided head on with a semi-truck. In the other incident, two workers died in June when their work truck crossed over a centerline and crashed head on into a loaded gravel truck. Oregon OSHA did not investigate those cases.

In the remaining three vehicle crash cases, one driver was injured when his truck crashed in a whiteout along a black-iced stretch of Interstate 84, and two drivers who were not wearing seatbelts were injured in separate crashes when their vehicles overturned.

Note: Generally, Oregon OSHA investigates a crash only when it appears an employer did not enforce a requirement that would have prevented the incident. Just as police do not cite every driver involved in a vehicle crash, Oregon OSHA does not cite every employer whose employees are injured in crash-related incidents.

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