RV Driving in Adverse Weather Conditions (Part 1 of 2)

November 12, 2009

Even though most RV’s will never see winter weather while travelling, they are exposed periodically to bad and possibly violent weather. High gusting winds, torrential rains, driving hail and thunderous lightning bolts have all been experienced at one time by many of us. The fear of visible or embedded tornados and like-cyclonic disturbances is real and RV’s are particularly vulnerable. Almost all RV’s have a relatively high center of gravity and a poor vertical body structure to weight ratio. In other words, they can be adversely affected by winds.

So, how do we deal with these trailers and motor homes when faced with an impeding storm on the open road? Of course, the easiest way, depending on the storm’s severity, is to cancel that day’s travel. But, many times you are already on the road, and it develops without warning. Let’s look at each element and the best strategy to adopt.

Wind – Can be an issue even on an otherwise nice day. A fast moving front or a steep pressure variation can produce substantially strong winds. Also geographical terrain, such as mountainous areas, can also deliver unexpected high winds and gusts. The affect of these winds on an RV can cause difficulty in maintaining its lane when running down a road or highway. This occurs when the wind speed is in the high twenties to the mid forties, depending on the size and weight of the vehicle. Wind gusts, as opposed to a steady wind state, can amplify the problem greatly. There are many accidents that are a result of driving in high wind conditions. These range from damaging a mirror from striking a passing truck to leaving the road due to loss of control.

Know your vehicle and control level in windy conditions. If you are driving with white knuckles or become nervous, you have passed your RV’s comfort level. Slow it down. As a general rule, I reduce speed by 10% when wind conditions are between 15 and 20 MPH and additionally a further 10% for every 10 MPH over 20. Never however, on a clear day, albeit windy, drive at a speed less than the minimum posted. If such a speed is warranted due to wind, it is time to stop. Winds approaching 50 MPH can cause dangerous driving conditions, and even more so if it is also gusty. In high winds or when you are out of your comfort level, either stop for the day or re-route to a slower road where you can drive with full lane control. In many cases driving or towing an RV in winds at or above 50 MPH may endanger both property and safety of yourself, your passengers and those in the immediate area. Remember, you might be able to hang onto it, but can that panel truck passing you?

Can RV’s blow over? Yes, all RV’s are capable of being upset by the wind force. Fortunately, in general, it takes a considerable wind force, far more than you would think to flip a trailer or motor home. Of course there are many factors that vary the wind speed required to cause this to a given vehicle.

Heavy Torrential Rain – Heavy downpours can present a challenge. The faster you are travelling the worse the affect will be. Windshield wipers, in many cases, can not remove the sheets of water quick enough. Additionally, forward visibility is greatly reduced making it difficult to see the road surface and other vehicles, both of which are important to observe. It is important to watch for puddle build up to avoid possible loss of control in a deep water body, and other vehicles that are running ahead and beside you. Careful observation of smaller vehicles, like cars, is important. As you may be sitting much higher in your tow vehicle or motor home, you are impeded far less by the ground spray. This ground spray is caused by the rain drops bouncing off the road surface creating far lower visibility for several feet above the road. For this reason, be prepared for these vehicles to slow abruptly. This can be deceiving if you are viewing them from a high class A coach. They may appear to be slowing too much. This is due to their visibility being far less than yours as your view is somewhat higher above the road. During any rain event be sure to turn on your headlights, even if your vehicle is equipped with daytime running lights. Tire spray can obscure the rear of your rig, and the taillights will help other drivers see you.

During any heavy downpour, it is wise to pull over and wait it out. This however, is difficult with a large vehicle or vehicle combination. Avoid pulling to the side or shoulder of a highway unless absolutely necessary. This area is far too dangerous as trucks and cars pass closely by. A rest stop or other large area is ideal. These heavy precipitations usually are very short lived, so you can soon be on the road again.

Lightning – Lightning can be dangerous, even while you are in your RV, driving or stopped. During lightning storms avoid contact with items that are grounded to the chassis, such as door handles or seat belt anchors. In case of a vehicle strike, these may become conductors for the high voltage discharge. If you are able to stop during an electrical storm, do not park near tall trees or telephone poles for fear they are brought down on your rig.

The speed of sound travels at roughly 1200 feet per second, this varies slightly depending on humidity and temperature. Therefore, you can calculate about how far the current lightning is from you by counting the seconds between, seeing the flash, and hearing the thunder. Dividing the number of seconds by 5 will give you an idea of the distance it is from you in miles. Remember though, if you are travelling at 60 miles per hour, you may be shortening that distance at the rate of 1 mile per minute.

These are just some of the thoughts of driving and dealing with common weather events. Next week, we will look at the chance encounter of a potential violet event, such as a tornado. We will examine how to possibly spot early signs of an oncoming tornado and how best to deal with it while driving.

With a Storm Safe Forecast – Lug_Nut – Peter Mercer