Driving in snow might not seem too relevant this time of year (May), but here in the Cascades in Oregon we are still having winter weather with snow as low as 2000' and heavy snow above 4,000' through Memorial Day weekend. That means anyone heading over any of the mountain passes could still encounter heavy snow.
Most of us would probably prefer not to drive our RVs or pull our trailers in the snow. Usually we prefer warmer weather for all of our outdoor recreation but sometimes we might get caught in an unexpected snow storm. Of course, folks involved with winter sports may choose to drive in the snow for snowmobiling, skiing, snowboarding, ice fishing, and snow camping.
Snow and the ice that often accompanies weather cold enough for snow reduces the grip our tires have on the road to near zero. Just wet roads have only half the traction of dry ones. Snow and ice can reduce the grip to near zero. Even a few inches of snow can make road surfaces so slippery we might have trouble even getting out of our own driveways! Our vehicles are totally dependent on the tires gripping the road for acceleration, stopping, and turning -- when they loose grip, we loose control.
It should go without saying that you should never use your cruise control when driving on slick roads. Many drivers enjoy the extra comfort and alleged fuel savings associated with using cruise control, but using it when driving on snow or ice is a recipe for disaster. You need all the sensitivity to vehicle behavior and control you can get. You don't want cruise control suddenly boosting acceleration and causing your wheels to spin or even causing you to totally lose control of the vehicle!
A second problem associated with driving in snow is getting stuck. While deep drifts are possible on many roads, it doesn't take really deep snow to trap a vehicle. I even had a 4WD SUV stuck in about 1 foot of snow in my driveway because it was enough that the pan under the body basically floated the SU until the tires couldn't get enough traction to move it. You can encounter drifts even on well-plowed and well-traveled highways when the winds are strong enough. I once encountered snow drifts 3' deep as part of a convoy driving down from a mountaintop military installation. I was only 3rd behind the snow plow, but we were driving in a blizzard with lots of falling snow and high winds that created drifts faster than the plow could cut through them. One of the keys to getting through deep snow is to maintain momentum. You don't need to be moving fast but it helps if you can keep moving. Avoid deep snow if you can. Even with 4WD, which is pretty rare on motorhomes but can be found more often on vans, pickups, and SUVs, pushing through really deep snow can be difficult if not impossible.
Tire chains can sometimes be enough to cut through snow. Make sure they fit your vehicle and are properly installed to avoid serious damage to your vehicle. Driving with tires chains requires you to drive slower. There are debates about whether to put chains on the front or rear of 4WD vehicles. My recommendation is to install them on both for best results in snow. You only need them on the driving wheels on 2WD vehicles. Front wheel drive vehicles usually get better traction than rear wheel drive and having tire chains on front wheel drive helps with steering as well as traction. Tire chains can also help on thick ice, but have a limited affect on black ice and can sometimes actually reduce traction if you end up sliding on the chains when a rubber tire might provide a better grip. Always take care when installing tire chains. First, make sure your vehicle is safely out of traffic. One way to install chains is to lay them out in front or back of the tires, drive on to them, then wrap them around the tires and secure them in place. Sometimes the wheel wells do not provide enough clearance to get your hands in to handle the chains. In that case you may have to jack up the vehicle to lift the body enough for you to install the chains. Be sure to set the parking brake and chock the wheels before using the jack. Close clearances may preclude the use of tire chains as the chains will fly up a little off the tires when in use, even when fully tightened. Make sure you have enough clearance!
In some cases local laws may allow you to use traction tires or 4WD in lieu of tire chains. A few places in the United States may even require traction tires. Be sure that you know the restrictions for each snowy location you drive in and that your vehicle is properly equipped. Traction tires are not simply snow tires or all terrain tires. They are specially constructed for maximum traction in snow and ice and are labeled. Traction tires are labeled with a mountain/snowflake symbol like one of these molded into the sidewall:
Another major problem when driving is snow is visibility. Falling and blowing snow can seriously inhibit visibility -- both what you can see and who can see you! Sometimes it gets bad enough to create what they call a white out where it is literally impossible to even tell up from down, let alone distinguish any landmarks or read road signs. When that happens your best bet is to find a safe place to pull over where you are out of traffic and wait for it to clear up enough to see where you are going. If possible put out some road flares or other warning devices and leave your flashers on so approaching vehicles don't run into you. Falling and blowing snow often sticks to road signs so they become unreadable. In such cases it is really helpful if you have some kind of GPS device to aide you in navigation since you won't be able to read speed limits, curves, exits, or distance signs. When falling or blowing snow makes hard for you to see the road it also makes hard for other drivers to see you. Turn on you lights to make your vehicle a little it more visible through the snow. Don't use your high beams in snow when it gets dark as the snow will reflect a lot of light back at you and make it even harder for you to see. Using high beams to make your vehicle more visible during daylight hours is OK, but remember to dim your lights for approaching vehicles. You want them to see your vehicle but you don't want your bright lights to impact their vision.
Windshield washers can help keep your windshield clear but you MUST use freeze-protected washer solution. Even if it stays warm enough where the reservoir is located to keep it from freezing unprotected solution will freeze instantly when sprayed and spread on cold glass. If it does get cold enough to freeze the reservoir it will probably crack and be destroyed.
Unless you grew up where you had snowy winters you probably don't have much experience driving on snowy or icey roads. I am grateful that I did grow up in a real 4-season climate and began learning snow driving techniques from my Dad long before I ever got behind the wheel. If you have any opportunities to practice driving in the snow in controlled conditions, jump on it! There really is no substitute for hands-on experience. You don't want your first run in the snow to be somewhere where everything is unfamiliar and out of your control.
Anytime you have reduced road friction or reduced visibility (rain, sleet, snow) you need to slow down and allow yourself more time for just about every maneuver. Spinning tires will make it take longer to get your vehicle moving. Slippery surfaces will make it much, much harder stopping your vehicle. Slick roads and turn ordinary curves into potential slide outs and dangerous death traps. Modern ABS braking systems are helpful. Before ABS we learned to pump the brakes so the wheels had a chance to turn now and then instead of locking up. Once the wheels are locked up you have NO steering! That little patch of rubber on the road has no sense of direction and your vehicle will continue moving in whatever direction inertia takes it.
Driving in snow increases the probability of being stranded AND increase the consequences if you are. Always wear warm coats and carry extra coats and/or blankets and winter gloves. Bring along some high-energy snacks and plenty of drinking water. Make sure your provisions are protected from freezing. A good first aid kit should be something you always have in your vehicle. Same with road flares. Road flares can not only be used to warn other drivers so they don't run into your parked vehicle they can be used to help direct traffic and used to start fires if you need to get warm.
If stranded, stay in your vehicle if you can. I have heard warnings that ordinary cars and trucks loose heat rapidly and you shouldn't stay in them if stranded in the snow. But think about it: are you better off in your vehicle out of the wind and snow or stumbling around outside in the weather? In addition, your vehicle will usually at least start off a lot warmer than it is outside. Snow covering your vehicle will also act as insulation, just like an Eskimo's igloo. In fact 1 foot of snow provides as much insulation as the R-13 fiberglass insulation in the walls of your home. Staying in your vehicle is especially helpful when there is more than one person as the enclosed space captures and allows you to share body heat, which you definitely could not do outside. The human body creates about as much heat as a 100 watt incandescent light bulb. To give you some idea how helpful that is, 100 watt bulbs are often used in residential pump houses to prevent well pumps from freezing. If your vehicle is an an unsafe position you may need to abandon it in favor of a safer place to wait things out. If you do, try to leave information in your vehicle about who you are, how many of you there are, what you are wearing, and where (at least what direction) you are planning to go. Chances are rescuers will find your vehicle before they find you out in the storm and the more information they have the easier it will be for them to find you.
Dress for the weather whenever traveling in winter conditions. Dress in layers, starting with thermal underwear and warm socks. Be sure to include a waterproof or at least water resistant outer layer. Most waterproof garments also offer pretty good wind protection. Include warm gloves and a baclacava or face mask in your preparations, even if you don't need them while driving as you might need them if you get stranded or have to leave your vehicle.
Driving in snow is no picnic, not even in your daily driver, let alone a big rig of some kind. But, if you are out in the snow, you probably weren't planning on a picnic anyway! If you have to drive in the snow, take steps to make sure both you and your vehicle are properly prepared for it. Yes, people have perished in snow storms. You want to do everything you can to avoid them and to be prepared to drive safely and survive in them if you have to.
S'now picnic out there!