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I Can Drive.... 65

The Challenge of Driving 65


That was where the arrow pointed on his speedometer as he glanced down for what must have been the hundredth time. He sat back in his seat stretching his arms and sighed as yet another 4 wheeler blew by reminding him that everyone else was going at least 80.

Today was just not his day. He was delayed at the last stop. And no amount of urgency that he tried to instill in the dock workers had worked to get him back on the road faster. Now he was way behind and knew that there was no room for any further delays if he was going to make that last stop in time.

Today, of all days, he wanted desperately to push that needle up the gauge just a little farther. Anything to gain back some breathing room on his clock anyway possible. But it just wasn’t going to happen. Even if he didn’t agree with his company’s policy, his truck was governed and was not going to go any faster.

John, however, did actually agree with his company's stance on speed. It was on days like this, with time running thin and traffic whizzing by, that he sometimes struggled to remember why. But there were good reasons. Settling into his seat, John concentrated on relaxing his shoulders, it took a special effort on days like this, and tried to think about the bigger picture.  About getting home safely to his family and maybe earning a little bit of the fuel mileage bonus his company offered.

The ATA has long pushed for limited speeds for not only large trucks but all vehicles. In a statement they made in 2015, “slowing trucks down will reduce the frequency and severity of crashes.

Many have argued that letting trucks drive faster would actually reduce the chance of accidents by preventing bottlenecking on highways. The theory suggests that slowing trucks down creates congestion that leads to more accidents.

But there are a few other factors to consider.

Momentum = Mass X Velocity

As a kid, I remember watching my favorite cartoons and laughing hysterically as time and time again that dumb coyote both defied and got beat by the laws of physics.

Unfortunately, in real life, physics is not such a laughing matter.

Take momentum for an example. Basically, the heavier an object is, and the faster it is moving, the longer it takes to stop. So a fully loaded rig running down the highway at 80mph is going to take much more distance to stop than the same rig traveling at 65 mph. See this link for more explanation.

This means that if we are traveling at higher speeds we need to maximize the amount of space we have to stop in case of an emergency. This could mean that we need to be able to react to sudden changes in road conditions sooner. but…

Time is NOT on our side

Driving at higher speeds does not only mean longer stop times. It also means we have less time to react in emergencies. Unfortunately, the human body has limitations. Whether you are driving 65 or 105, if an emergency occurs you are always going to react as fast as possible. Typically that means you are reacting at the same speed regardless of how fast you are traveling. The end result is that you will cover that much more distance before your reaction has an effect when you are traveling at higher speeds. Whether that distance is a matter of feet or yards, it could make all the difference in avoiding the accident.

Flying Rubber Birds

And what about your equipment? Running at higher speeds for extended periods of a time means more wear and tear on your truck. Especially where the rubber meets the road. In fact, most on-highway heavy-duty tires are rated to operate at max speeds of 75mph.  Running at higher speeds for extended periods of time can cause significantly faster wear and increased chances for a blowout. Most professional drivers can handle a blowout without incident.

But what about the 4-wheeler behind you?

Imagine his surprise when a giant piece of rubber, that looks a bit like a crazed bird dive-bombing his windshield, comes flying out of nowhere. Now he has to react and he is probably going to do one of two things. Swerve to miss, or slam on his breaks. Or possibly even both. Since we understand momentum, we know that his little car is going to stop much quicker than the 18-wheeler behind him traveling at the same speed. I think you can imagine how the rest of this scenario could play out.

Fattening your wallet

While safety should be enough, it is not the only reason to ease off that gas pedal.

Slowing down to 65 or less will get you the most bang for your buck in fuel mileage. In many cases, fleet drivers can earn a bonus for maintaining better fuel economy. For owner-ops, the savings will go straight to the bottom line. In short, slowing down, even just a few miles per hour, could add up to extra cash in your wallet. And who doesn’t like extra cash?

Glen Kenzie of the ATA states: "As a rule of thumb, for every one mile per hour increase in speed, there is a corresponding 0.14 mile-per-gallon (mpg) fuel consumption penalty,”

On average, this equates to a more than 20% increase in fuel mileage just by driving 65 mph instead of 75.

The Challenge

Give 65 a try for 2 weeks. See how it works out for you.

Afterwards, ask yourself the following questions.

  • Did you still make your stops on time?
  • How was your stress level/blood pressure the 2nd week?
  • Did you see an improvement in your mpg?

You just might be surprised at the results.

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