Rules of the Road

Drivers of bigger vehicles have bigger responsibilities – and people are watching

If you drive a large trucks or SUVs and those with trailers, commercial or not, it’s important to recognize with great size comes great responsibility, and law enforcement is watching.
If you drive a large trucks or SUVs and those with trailers, commercial or not, it’s important to recognize with great size comes great responsibility, and law enforcement is watching. File

Question: I drove back last evening from Seattle to Bellingham, and I was disturbed by the oversized, raised pickups that were speeding in the left lane, some with trailers behind them. I’ve also seen tandem dump trucks tailgating on Interstate 5. What is the policy on speed enforcement of such vehicles as the oversized pickups and those with trailers? Are there statistics on such vehicles and collision rates?

Answer: On the surface this looks like a question about speeding trucks, but there are a lot of sub-topics crammed into those few sentences; modified vehicles, trailers, commercial trucks, tailgating, enforcement policies and collision data. I’ll see if I can tackle all of that in the next few paragraphs.

Since the questions were prompted by a trip on I-5, I thought it would be helpful to talk with a Washington State Trooper about their enforcement practices. Much of what you read here is informed by that conversation.

Let’s start with the speeding question. There isn’t a state policy directing troopers to focus a specific amount of speeding enforcement on pickup trucks or drivers towing trailers.

However, the laws of physics have proven that bigger vehicles are more deadly in a crash, and jacked up vehicles crash more frequently, so large speeding vehicles certainly get their attention.

Also, there are some violations specific to those vehicles that get enforced.

The “oversized, raised pickups” mentioned in the original question can be a safety hazard and a violation of the law:

If the tires stick out past the fenders throwing rocks and other debris at other drivers.

If the bumpers are too high negating the engineering that goes into protecting drivers in a crash

And for oother safety-related equipment violations.

On sections of the freeway that have three or more lanes in one direction, vehicles over 10,000 pounds and vehicles towing trailers are not allowed in the left lane.

The part of the question about the tailgating tandem dump truck gets us into commercial vehicle territory. The State Patrol has a division dedicated to commercial vehicle enforcement, but it’s more focused on violations specific to (big surprise) commercial vehicles; things like load limits, log books and vehicle inspections. That doesn’t mean that traffic violations by commercial drivers go ignored.

In addition to day-to-day enforcement efforts, state and local agencies regularly conduct emphasis patrols for commercial vehicles that include speeding and following too closely.

You may find it interesting to know that when officers conduct these emphasis patrols, they often stop drivers of non-commercial vehicles.

What’s the usual violation? Cutting off commercial vehicles. Not only is it a violation of the law, it’s also dangerous to the point of being borderline nuts.

It takes a passenger car traveling 60 mph roughly 300 feet to stop on dry pavement. A loaded semi, which can be up to 80,000 pounds, takes more than 500 feet to stop from the same speed. If a driver cuts off a semi truck and then has to stop quickly, well, physics rules the outcome.

Now for the part about collision data. Yes, there is a lot of it. The trick is trying to determine what is useful.

In 2016, of the 536 fatalities in Washington state, 204 were occupants of cars while 125 were occupants of pickups or SUVs.

But that data alone isn’t all that helpful in determining crash rates. We’d also want to know how many miles cars drive compared to pickups. That’s not as easy as you might think; the Bureau of Transportation Statistics tracks that by wheelbase, not vehicle type.

If we’re willing to assume that short wheelbase vehicles include mostly cars, while long wheelbase vehicles include mostly pickups and SUVs, passenger cars drive about three times as many miles as light trucks, at least nationally. (They don’t have their data broken down by state.)

Per mile driven, that would suggest that cars crash less. Crash data also show that pickups and SUVs are at a disadvantage when it comes to handling dynamics (think forward balanced weight and high center of gravity). That’s why pickups and SUVs are more likely to be in single vehicle fatal crashes than cars.

In 2016 commercial vehicles were involved in 50 fatal crashes. That doesn’t mean that commercial drivers were at fault in all of those crashes – in one notable example in Whatcom County, a speeding and impaired driver attempted to pass a semi and caused a head-on collision with an oncoming car.

Of those fatalities, only 10 were drivers of commercial vehicles. Commercial drivers cause less fatal crashes, not only in overall numbers, but also per mile driven. That makes sense; commercial drivers have a higher standard of training and licensing, along with more laws to obey and higher levels of enforcement.

If you drive a large vehicle, commercial or not, it’s important to recognize (to misquote Uncle Ben from Spiderman) with great size comes great responsibility.

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Doug Dahl, Target Zero Manager for the Whatcom County Traffic Safety Task Force, answers questions about road laws, safe driving habits and general police practices every Monday. Ask him a question using our form. Target Zero is Washington’s vision to reduce traffic fatalities and serious injuries to zero by 2030. For more traffic safety information visit