Ambulances & Vehicle Ops, Equipment & Gear, Training

Winter Driving Tips

Issue 11 and Volume 37.

In severe weather, schools close and businesses keep employees at home, but EMS providers are required to find a way to respond to incidents, which means driving under some of the most treacherous winter conditions imaginable. Although patience and common sense are two strategies to employ, here are several others to keep in mind.

Don’t Be Your Own Victim
The fact of the matter is that EMS vehicles are subject to the same physical constraints as other production vehicles, and that includes the opportunity to get stuck or stranded. There’s the old joke that the only difference between two-wheel drive and four-wheel drive is how badly you get stuck, and heavy EMS rigs like to sink in deep snow and mud, four- wheel drive or not. Because of this, there’s a real chance you might get stuck somewhere it takes hours for a plow or rig to reach.

So in addition to checking your rig for the usual medical and technical supplies, throw in a cooler full of energy bars, water and other snacks in case you get stranded. Make sure you have a few space blankets too; keep in mind stranded motorists may seek refuge in your rig as well—and they probably won’t have water or food with them. I’ve personally been in icy, mountain road situations in my all-wheel-drive patrol rig where the roads simply became impassable, forcing me to wait for a plow in lieu of getting really stuck and not being able to help anyone, including myself. I’ve even had both of my windshield wiper blades snap in two at one time in a heavy late-night storm, causing me to follow a plow down the mountain blind to a safe spot. What are the odds of that? But it happened. You can bet I made sure I had spare wiper blades and arms in the back of my rig after that. So plan ahead for the unexpected because it may just happen.

Know Your Rig
Modern day EMS rigs have a tremendous amount of technology packed
into the chassis and drive systems that are designed to keep you safe on the road. However, you should take time to educate yourself on its capabilities in order to take advantage of this technology.

For example, if your rig has traction control, the time to find out how it works is not in the middle of a snowstorm. The same goes for four-wheel drive and all-wheel drive systems. There is a difference between the two. Do you know which one you have? If you know your rig has four-wheel drive, does it have a full transfer case allowing 4-HI and 4-LOW operation, and does it have manual or automatic locking differentials or center-locking differentials? Do you know what each mode does and why? Is it full-time or part-time four-wheel drive? Does it have a limited slip? Have you tried the various operating modes before heading out into the wintry stuff to know which mode works best for a given traction condition? Simply “sticking ‘er in low and powering down” isn’t the best choice, and it could get you stuck where you wouldn’t have had you taken the time to understand the rig’s capabilities.

Remember that four-wheel drive does not give you better braking or steering; tires do. Four-wheel drive allows power to be delivered to a drive wheel to provide propulsion if the tires have traction. Yes, there’s driveline drag through gear multiplication that can help you reduce speed quicker through throttle modulation, but that has nothing to do with brakes and everything to do with tire traction. Absent from that, you simply have four tires spinning or sliding instead of two.

You should also consider braking. In many vehicles, four-wheel anti-lock braking system (ABS) disengages on part-time four-wheel drive systems and also on full-time four-wheel drive and all-wheel drive systems when the center differential is locked (if equipped) or the transfer case is placed in low range? This is due to the front and rear axles being “forced” to turn at the same speed, which can confuse the ABS sensors. This matters if you’re making your way down a deep, icy or snowy road in low gear or with a center-differential locked because you won’t have brake modulation and steering control that ABS provides should you have stop quickly. So you must adjust your driving accordingly. But you won’t know to do this if you first don’t understand how your rig is configured.
What about tires? Are you relying on all-season tires (which do everything average but nothing spectacular) to handle heavy winter duty, or have you switched to softer compound, siped snow tires that are made to be driven in temperatures under 40°? Do you know what’s on your rig? And tire chains? If you had to stop on the side of the road or attach chains to your rig, would you know how to do it? Could you do it in a pounding snowstorm?

If the answers to any of the questions above are either “no” or “I don’t know,” then every person in your rig needs to get together to ensure they know its capabilities. If you don’t, you’re setting yourself up for potential failure. Think of it this way: You wouldn’t intubate a patient without first training yourself on the equipment, processes and limitations. So why wouldn’t you do the same with the very rig you depend on to get to the call and that simultaneously presents the greatest hazard to your personal well-being?

Driving an EMS rig in winter conditions requires patience and slowing down, but many times operators get in trouble because they simply exceed the operating capabilities of their rig in the given conditions. This can stem from over confidence, but it can also come from lack of training. We’d like to believe otherwise, but we’re susceptible to the same perils as the ordinary driver, and having decals on the side of our truck doesn’t change that.
So take the time to know your rig before heading out into the wintry muck, and make sure you have enough supplies and equipment should you inadvertently find yourself part of the problem rather than the solution. Above all, know your own driving limitations and give yourself the buffer you need. Getting there slowly is better than never getting there at all.