A key driver training point - Match your speed to the visibility
It has happened again. There has been a major pile up on a high-speed highway. This time, it happened in Oregon and involved over 60 vehicles, 20 of them commercial vehicles. Sadly, there was a fatality.
One reason these crashes keep happening: “Investigators currently believe the heavy fog was the primary reason behind the crash.”
A road or weather condition cannot be the reason for a crash
The basic principles of defensive driving are the driver must see, decide, and act. In this case, the drivers should have seen the reduction in visibility, decided to reduce speed to match the visibility (a driver should always have 12 to 15 seconds of forward visibility), and then taken the appropriate action (reduce speed). In other words, it was not the fog that caused the accident, it was the action, or lack of action, by some of the drivers involved.
It’s all about having the time to see, decide, and act
The lack of visibility becomes an issue when a vehicle slows to an unsafe speed or stops on the roadway. Consider this: If a vehicle has stopped in front of you and you have one to two seconds of visibility, by the time you see the vehicle, decide to hit the brakes and/or steer to avoid it, you will hit the other vehicle before you can even start to act. This is because it will take you at least a second to see and perceive the hazard, and about three-quarters of a second to react. This is why reducing speed to increase visibility in such situations is critical.
Poor excuse
The fear of being hit from behind if they slow down is what some people use as an excuse to maintain highway speed in poor visibility.
However, this is only a valid concern if you slow to an unsafe speed or stop. This is because the hazard occurs when the following vehicle is closing on the other vehicle with a high speed differential (65 mph versus 0 mph, or a closure rate of 98 feet per second). This is not a significant hazard if we are talking about a speed differential of 65 mph versus 45 mph, or a closure rate of 30 feet per second.
Also, if you are struck in the rear with a speed difference of 20 mph, this is an entirely different crash than hitting an extremely slow or stopped vehicle at full highway speed.
Preaching to the choir
The fact that a road condition cannot cause a crash and speed must match visibility is not new information. If you are a defensive driving instructor or a safety professional, you have known this for years. But do your drivers know and understand these concepts?
Key to remember: To help your drivers avoid being involved in a multi-vehicle pileup on a high-speed highway, conduct regular training on defensive driving. In other words, you need to be preaching about adjusting speed to conditions to everyone else.



















































