Hazardous Driving Conditions: Road Rules for Handling Adverse WeatherUpdated Aug. 23, 2019
Unfavorable weather and road conditions can create hazards that make driving difficult, and more dangerous. You must learn how to identify and compensate for these hazards, to protect yourself and other road users from harm. Of course, the number-one rule of defensive driving is to avoid unnecessary danger. Choosing not to drive in rain, snow or fog, at night or during any other hazardous conditions is always the smartest decision.
Unfortunately, hazardous conditions can occur in any climate and during any season, despite your best efforts to avoid them. When your visibility or vehicle control are impaired by adverse conditions, the guidance provided here and in your state’s driving manual will help you handle the situation.
Driving at night is far more difficult and dangerous than driving during the day, primarily because your visibility is dramatically reduced. In darkness, it is much harder to see and be seen by other drivers. As the winter months approach and the days grow shorter, you will often need to compensate for poor visibility and additional hazards.
Driving safely at night hinges on maintaining a reasonable speed, and appropriate use of headlights. On rural roads and open highways, your high-beam headlights will maximize visibility. However, you must never use high-beams in close quarters with other road users, as you may blind them and cause an accident. Stick to low-beam headlights in built-up areas and when you are in close proximity to other drivers. It is essential to reduce your speed and drive “within the reach of your headlights”, otherwise you will not have time to react to hazards as they enter your field of vision.
Wet weather always makes driving more hazardous. Whether traveling during light rain or torrential downpour, drivers will have to contend with reduced visibility and slippery roads. To compensate for low visibility, reduce your speed and make sure your headlights, taillights and windshield are all clean. Grime on headlights can make them up to 50 percent less effective and you will need them in tip-top condition when driving through heavy rain. Always use low-beams in this situation, as high-beams will reflect off the moisture in the air and cause glare.
Even a very small amount of water can turn the surface of the road into an ice rink. Water collecting in pools on the road is dangerous, though thankfully, relatively easy to spot. Slightly damp roads can pose more of a hazard, as the water may loosen oil and chemicals which have become ingrained in the asphalt. Be mindful of slick roads and reduce your speed when the roadway is wet. Use your brakes with caution, in a gentle and controlled manner, to avoid sliding on a slippery road.
Hydroplaning causes partial or complete loss of steering and is a risk when water accumulates on the roadway. This hazard occurs when your car hits a pool of water fast enough to glide across its surface. Contrary to common belief, vehicles can hydroplane on a film of water just one tenth of an inch deep. The faster you are traveling, the greater the likelihood that hydroplaning will occur, as speed creates “lift” and reduces your car’s grip on the surface of the road.
You can avoid hydroplaning by reducing your speed on wet and rainy days. Never use cruise control on a wet road, as your vehicle may accelerate if tires lose connection with the asphalt. Worn tires and incorrect tire pressure make hydroplaning a risk at lower speeds, so be sure to keep your tires in good condition. To recover from hydroplaning, do not panic or brake suddenly – this will only worsen the situation. Instead, ease off the gas pedal until you can feel your tires regain connection with the road.
Water on the roadway that is more than a few inches deep is extremely dangerous and must be avoided. Six inches of water can cause loss of control, 12 inches will float most vehicles and two feet will float pick-up trucks and SUVs. A floating vehicle may be swept off the roadway into a deeper body of water. If this happens, the car could roll-over and fill up before you have a chance to react. Should your car stall in water, you must get out and seek higher ground immediately.
When driving through pooled water or heavy rain, your brakes may get wet and become ineffective. This can quickly be rectified by pulsing the brakes in a low gear to shake off the excess water. It is advisable to use this brake-drying technique before you need to use the brakes, if you suspect they may be wet.
Strong winds can be a problem for all car drivers, though they are a particular hazard for drivers of light-weight vehicles, vehicles towing trailers and high-sided recreational vehicles. You are most likely to be exposed to high winds or strong gusts of wind during a storm, or when traveling through exposed areas such as bridges, culverts and mountain passes. Be aware of these high-risk situations, stay alert, and keep both hands firmly on the steering wheel.
Always keep an eye out for flying debris and other obstacles on the road ahead, when traveling in extremely windy conditions. Reduce your speed to allow more time to react, should you need to evade an approaching hazard.
Thick fog makes for extremely poor visibility. In foggy conditions, you may not be able to see pedestrians, other vehicles, road signs, road markings or obstacles. Significantly reducing your speed is the only way to stay safe when driving through fog. Headlights should be switched on to improve visibility and make sure your vehicle is seen by other road users. As with rain, drivers must stick to their low-beam headlights as high-beams may cause glare and worsen visibility. Some states permit the use of fog lights; check your driver’s manual for details.
Drivers should avoid passing, crossing or merging with other lanes of traffic in foggy conditions, as limited visibility may lead you to misjudge another vehicle’s distance and speed. Drive as cautiously in patchy fog as you would in consistently thick fog, as you could enter a denser stretch of fog at any point and lose visibility altogether. Be aware that the surface of the road may be slick with moisture during foggy conditions.
Like fog, driving through smoke can dramatically reduce visibility. When driving through smoke you must be aware of additional dangers. There may be a fire nearby and smoke can cause asphyxiation.
Driving in extremely hot weather can put your health at risk and damage your vehicle. To avoid getting stuck by the roadside in soaring temperatures, make sure your car is hot-weather ready before commencing your journey. All fluids must be topped up, tires must be appropriately pressurized, and your battery should be in good condition and corrosion-free. Check the vehicle temperature gauge regularly and pull over if there is a chance your engine may overheat.
Vapor lock and tire blowouts are the two most common mechanical failures which drivers experience in extreme heat. Your vehicle will likely sputter and die if vapor lock prevents gas from reaching the engine. If this happens, pour water over the engine and fuel lines and only attempt to restart the vehicle when it has cooled. Tire blow outs are typically caused by under-inflated tires. Always check your pressure and bring a spare if possible.
Never leave children or animals in a car unattended on a hot day. While traveling in extreme heat, stay hydrated and cool by drinking plenty of water and using the air con, or open windows to ventilate the car.
Bright sunlight can impair your vision and even cause temporary blindness. Drivers are most at risk of sun glare in mornings and late afternoons, when the sun sits low in the sky. Glare can be worsened by moisture and dirt accumulation on both sides of your windshield, so be sure to clean the outside and inside regularly. You may also wish to keep a pair of strong sunglasses in your glove compartment for particularly bright days.
Pull over to the side of the road if you encounter glare severe enough to completely obscure other vehicles or road signs. You can consider a different route or recommence your journey when conditions have improved.
Snow and ice
Slippery roads are the biggest challenge you will face when driving through ice or snow. “Black ice” is especially dangerous, as it is difficult to spot. During freezing and near-freezing conditions you should reduce your speed, even if no ice or snow is visible on the road. When driving on particularly slippery surfaces you should avoid sudden changes in speed or direction, as this may send your vehicle into a skid.
Keep in mind that in most states, drivers are legally required to clear all ice and snow from their vehicles before a journey. If you are caught driving with a build-up of snow or ice on your vehicle or injure another road user with ice or snow that falls from your vehicle, you will be fined.
Use the following tips to prepare for a cold-weather journey:
- Add anti-freeze to your radiator. An overheating engine could indicate frozen radiator water.
- Keep your gas tank at least half-full as fuel may freeze in extremely low temperatures.
- Get your battery load-tested. It must be fully-charged to start the vehicle in freezing conditions.
- Fit your car with snow tires if you are likely to drive in winter conditions regularly. Keep snow chains in your trunk.
You must avoid driving in a blizzard at all costs. Low to zero-visibility, freezing temperatures and extremely slippery roads make blizzards the worst weather conditions for driving, by far. While the goal must be not to drive in such adverse conditions, you must know how to handle a blizzard and stay safe, should you get caught in one while out in your car.
During a blizzard, heavy snowfall may obscure your view of the road ahead and road markings, making it difficult to position your vehicle on the road. Reduce your speed and keep to the right-hand side of your lane, as it is common for drivers in this situation to drift too close to the center line. If visibility gets too bad, pull over to the side of the road and wait for conditions to improve. Be sure to put your hazard lights on to alert other drivers and recovery vehicles to your presence.
Pulling over during a blizzard is often the safest course of action, though you may be stuck for several hours at least. Keep an emergency supply kit in your car during the winter months, just in case you are stranded by the roadside. This should include food and water, first aid items, warm clothing, a blanket, a snow shovel, an ice scraper and anti-freeze, a flashlight and extra batteries.
Skidding and traction loss
The grip between your tires and the road’s surface is called traction. Reduced traction can be caused by a variety of factors and will leave your vehicle susceptible to skidding. In addition to adverse weather, traction loss can be caused by issues with your vehicle. The total weight of your vehicle and how that weight is distributed (over front tires, rear tires or evenly) affects your grip on the road. Understanding how this occurs will help you regain traction in an emergency.
While skidding is often caused by rain, mud, snow or ice, it can also happen when you turn, change lanes, brake or accelerate suddenly, as this can throw weight from one part of the vehicle to another. Locked wheel skids occur when traveling at speed and the brakes are applied too sharply. To correct this type of skid, you must remove your foot from the brake pedal. An acceleration skid may occur if your drive wheels lose traction. You can recover from an acceleration skid by easing your foot off the gas.
Your vehicle will grip the road’s surface more effectively when the wheels are rolling. If necessary, you may lightly pump the brakes during a skid. If your vehicle has an anti-lock braking system, you should apply firm and consistent pressure to the brakes without pumping them.
When your rear wheels skid, this is known as “oversteering”. Oversteering often happens when the driver takes a bend or lane-change too quickly, when the surface of the road is slippery. Front-wheel skids are referred to as “understeering”, this type of skid usually occurs in front-wheel drive vehicles when braking or accelerating too sharply.
Braking may be your first instinct when your vehicle begins to skid, though steering is the most effective way to correct traction. Both front and rear-wheel traction loss can be corrected by looking and steering in the direction you wish the vehicle to go. During rear-wheel skids, this will be in the same direction as the skid. In front wheel skids, this logic does not apply.
In both situations you should ease off the accelerator and brake, so that the wheels begin to roll and regain traction. Gently pumping the brakes may help during front-wheel skids, by shifting weight forward onto the front tires.
Getting out of snow or mud
Every driver must have a basic understanding of the tactics required to free a vehicle that has become stuck in snow, ice or mud. As always, prevention should be your priority. Make sure your car is prepared for the conditions in which you are traveling, by purchasing a good-quality set of all-terrain tires or snow tires. You should also keep a snow shovel and set of snow chains in your vehicle for emergencies.
Freeing your car from deep mud or snow takes patience. Use the following tips to help you:
If necessary, clear space around your tires. This is where the shovel comes in handy.
In a low gear, gently increase pressure on the accelerator to move the vehicle as far forward as possible, without allowing the wheels to spin.
Shift to reverse and repeat this steptraveling backwards.
Rock your vehicle back and forth using the last two steps, until it rolls free.
You may need to lay something under the tires to increase traction. Boards or tree branches will work well.
If you cannot free your vehicle, call 911 and wait for assistance. You can attract attention by securing a brightly colored piece of cloth to the outside of the car.
Using tire chains
Snow chains can be an enormous help in slippery situations, where it would otherwise be impossible to gain traction. During winter months in colder states, some roads will be impassable without snow chains. Check your driver’s handbook to find out what the laws regarding snow chains are in your region. It may be a legal requirement to use them in certain situations.
Make sure you know how to fit and use your snow chains before you must do so in an emergency. Once you have successfully installed the chains to your drive wheels, you will need to drive a short way to let them settle before adjusting them once more. Keep speed to a minimum and drive gently when using snow chains. Remember, they must not be used on bare pavement that is not covered in ice or snow.
Every driver will occasionally find themselves in a situation where an accident or collision seems unavoidable. Your ability to remain calm and take appropriate evasive action during such situations could mean the difference between life and death. In an emergency, you may either stop, speed up or turn, to avoid a collision. In general, steering away from a potential crash is a faster and more effective option than coming to a complete stop.
If a collision cannot be avoided, you must know how to minimize the impact of the crash to protect yourself and other drivers. For instance, it is always better to avoid a head-on collision, as it is to collide with a stationary object rather than with one that is moving toward you.
Be aware of hazardous conditions and always drive defensively. With any luck, you will not need to take evasive action or use escape techniques too often!
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