In my last installment, my focus was centered on the professionalism on display from my fellow commercial drivers during the ice/snow storm that pummeled many of our nation's southern states. The item I left out from my last blog was how all of the safety systems contributed to the successful outcome of the week's journey.
Let's start out with the simplest things, our tires. Today's tires have an incredible amount of traction in adverse conditions in comparison to the tires that were employed at the beginning of my career. When I first started driving, there were still bias-ply tires which in comparison to today's radial tires offered very little in regards to traction. Even radial tires are dramatically better on wet roads than radial tires from the early ‘80s. I still remember trying to slow down a truck early in my career when the road was wet and seeing the tires not turning. Instead, they were simply sliding on the wet road. Keep in mind this was not a panic stop and I was only using minimal brake pressure and the tires were already locked. In addition to the tires being locked, I was not slowing down appreciatively either. Today's tires with their rubber compounds and tread designs have improved our stopping distances in all weather conditions.
In the last paragraph, we got into a little bit of a skidding tire problem. This has been dramatically changed with the advent of the anti-lock brake system (ABS). A little bit of history, I was vehemently against the adoption of anti-lock brakes when they were first introduced. I was much younger back then. I grew up around farming equipment and racing and I thought that I could control a wheel and how it locked much better than any computerized whiz-banged system that they were going to put in our vehicles. Without going too deeply into that, let me simply say... I was wrong! Anti-lock brakes allow you to maintain directional stability while coming to a stop.
Many of today's younger drivers have never driven a vehicle without ABS. Quite simply, when a wheel is not turning and is skidding, the vehicle will head in the direction mass is taking it. Today, they have taken ABS a step further by combining them with stability control which varies the brake pressure to help the driver guide the vehicle in the direction they have chosen. This system is known as Electronic Stability Control (ESC). Quite simply, these systems detect when the vehicle is not responding to the driver's steering inputs and can vary the brake pressure at the individual wheel ends to assist the driver in completing their maneuver. Today's ESC works so seamlessly it’s possible for a driver to not even notice its engagement.
Next on my list of features is Automatic Traction Control or ATC. This controls the amount of torque that is applied to each individual drive axle wheel end. By using information collected by the ABS sensors, the truck is able to determine which wheels are spinning and which wheels have traction. The ATC uses vehicle brakes to stop wheel spin, causing the differential to transmit more power to the wheel with the most tractive effort available. Farmers have used this method of applying individual brakes side by side to transfer more torque to the wheel end with the most traction.
There was an event during this trip in which most of these systems engaged to successfully stop me from having a collision. While traveling up the highway, I had crested a hill where I saw flashing lights of a police car along with a long line of trucks with their hazard flashers lighting up the night. I applied the brakes and began to slow my Cascadia to fall into this line of trucks. The road was slightly downhill at this point. Prior to coming upon this situation, I had been using the left lane which was snow instead of ice. As I began to slow, I hit a pure sheet of ice! ABS, ESC, and everything engaged! I was able to maintain enough control to move the truck a little farther to the right which put the tires into some gravel and allowed me to come to a safe stop!
After coming to a stop, another driver came walking back to my truck and we walked up to the officer to find out what the situation was. The police officer told us that trucks were getting stuck getting up the next hill. He then mentioned to us that if they stayed in the left lane they were not having any problems. That was where I had previously been driving. But now I had been on the right side of the road. The officer informed us that once everyone got stopped on the right, they weren’t able to get going again due to the ice in the right lane. The other driver and I went back to our trucks and were going to try to get back to the left lane to continue our trip.
To give myself the maximum traction I had available, the decision was made to engage my inter-axle differential lock. The purpose of an inter-axle lock is much like the transfer case of a 4-wheel drive vehicle, it locks the front and rear axles of your tandem together. In theory, this should have been the best way to get out of this situation. When I tried to move forward, the truck immediately tried to slip to the right. At this point, I thought I was stuck for the night. After a period of time, feeling helplessly stuck on the interstate, I noticed my ATC switch on the dash. When you push on that button it overrides ATC which allows a wheel to spin without traction control intervening. I thought to myself, what if I just unlock the inter-axle differential and see if today's new technology will save the day. I will admit... I was not feeling terribly confident that ATC was going to be the answer to my dilemma. But sure enough, I eased into the throttle, ATC controlled the amount of torque being applied to each of my four drive tires, and we were able to graciously make our way over to the left lane and continue the journey safely.
In closing, as all these systems seamlessly interact with the driver and each other, it is best to not allow yourself to become complacent. Instead, be vigilant and drive like we don't have a backup safety system to save the day as we ply our trade on our nation's highways.