本文发表在 rolia.net 枫下论坛VEHICLE PREPARATION: For safe winter travel the vehicle must be in good mechanical condition, have clean motor oil of the proper viscosity (check your owner's manual), a cooling system with 50 to 100% antifreeze, and properly inflated tires with at least 50% tread. Drivers of assigned vehicles are responsible for monthly preventive maintenance safety checks and ensuring maintenance and annual inspections are done. Fleet management normally assumes the responsibility for preventive maintenance and periodic safety inspections of pool vehicles. However, all drivers are required to do a short pretrip safety inspection. Turn on the headlights and emergency flasher and walk around the vehicle. Make sure all the lights work and are clean. Visually check the tires, check for body damage, and ensure all cargo is secure. Under the hood, check fluid levels, belts, and scan for leaks. Make sure you have a fire extinguisher, first aid and body fluids barrier kits (usually inside the larger first aid kits), tire chains, a credit card, decent wiper blades, windshield washer antifreeze, and an ice scraper. Travelers need to be prepared with warm clothes, and possibly a blanket in case they become stranded. Adjust the mirrors, and familiarize yourself with the controls. With the engine running, apply hard constant pressure to the brake pedal for 5 seconds. The pedal should stop about half way to the floor and not settle. Set the emergency brake and gently try to move the vehicle. While driving, monitor the performance of the vehicle.
VISIBILITY: Make sure you can see and can be seen. Make sure all windows, mirrors, and lights are free of frost and working. Headlights must be on when visibility is limited or when traveling Forest Service roads, and they can be useful when traveling on some of our busy 2 lane roads. Windows of vehicles that have been parked outside overnight often frost up again when the vehicle is moved.
LOOK AHEAD & DRIVE DEFENSIVELY: Watch out for other drivers and compensate for their mistakes. They may have never driven on snow before or may not have adjusted their driving for winter. Regardless of the conditions, scan up to 15 seconds or more ahead of your vehicle. Look both ways before going through intersections - even when you have the right of way. The sooner you recognize a hazard, the more time you will have to slow down and deal with it.
SLOW DOWN & INCREASE YOUR FOLLOWING DISTANCE: Adjust your speed for road conditions and visibility. With less than ideal conditions you must drive, corner, decelerate, and accelerate more slowly. Increase your following distance as road conditions and visibility get worse. For example, with compact snow and ice your following distance should be 8 to 10 seconds.
HANDLING CHARACTERISTICS: As long as you do not try to turn or brake, the tires that usually lose traction first on slick winter roads are the driven tires, the tires connected to the engine by the drive train. This is due to the torque exerted by the engine when accelerating or decelerating. A decelerating car that has lost traction to its driven wheels will usually pivot around the tires that still have traction, the tires that are not driven. The following deals only with skids that occur when decelerating with very poor traction such as compact snow and ice.
FRONT WHEEL DRIVE: Even though front wheel drive vehicles usually have more weight on the front than the rear tires, the front tires can lose traction first when traction is poor. Because you have little or no directional control when the front tires lose traction, a skidding front wheel drive vehicle can be unpredictable and difficult to control. Most of the time it will plow forward in a straight line, but sometimes the front of the car will move left or right and pivot around the rear wheels. Simply put, the car will try to go where it is pointing.
FOUR WHEEL DRIVE: Four wheel drive is the least likely vehicle to skid, because the engine's torque is divided among four wheels INSTEAD of two. The disadvantage to four wheel drive is that once a four wheel drive vehicle does skid, it is the most unpredictable and DIFFICULT to control, because all four tires usually lose traction.
REAR WHEEL DRIVE: The rear tires usually lose traction first on a rear wheel drive vehicle. Since you steer with the front tires and they are more likely to retain traction on a rear wheel drive vehicle than with the other types, a rear wheel drive vehicle is often the easiest to control during a skid. As long as the skid is not too severe and the driver keeps the front tires pointing the direction of travel, a skidding rear wheel drive vehicle will tend to pivot around the front tires and skid in a straight line.
SKID RECOVERY: Basic skid recovery procedures for all vehicle types are: 1. Never panic or give up. 2. Turn the steering wheel the direction you want the front of the car to go. 3. Do not brake or accelerate.
TURNING: Slow down prior to turning and do not accelerate until you have trade the turn. When turning use just enough-brake application to control your speed when going downhill or just enough throttle to maintain your speed going uphill. Not trying to turn and decelerate or turn and accelerate wilt provide maximum available traction and minimize the possibility of a skid.
LONG AND LOW: The longer and lower the vehicle, the safer and easier it will be to control on a slick road. Vehicles with a high center of gravity are more likely to tip over if traction improves or they hit a rut when skidding. The shorter the wheel base, the distance between the front and rear tires, the more severe the skid and the more difficult it will be to recover froth a skid.
CRUISE CONTROL: Do not use cruise control when the roads might be slick. Cruise control can apply power suddenly or at the wrong time and cause a skid or make a small skid uncontrollable. If you have the cruise control on and realize the road might be slick, use the hand operated controls to turn it off. Tapping the brakes can initiate a skid if the roads are slick.
STRANDED: Do not panic. Remember, because you have informed someone of your itinerary, they will come looking for you. If stranded, stay with the vehicle. Tie a handkerchief or flagging to your antenna and turn on your emergency flashers. Keep a downwind window partially open when running the engine for warmth and make sure the tail pipe remains clear.
<h1>This following parts are from another article.</h1>
Pay attention to the road surface. If it looks slippery, it probably is. Drivers underestimate available grip on dry and wet roads, but overestimate traction in snow and ice.
Know that traction varies. Road conditions will change from simply slushy to glare ice to just damp. A heavily traveled interstate may have plenty of grip, while its little used off-ramp is a skating rink. One place for ice to build up is where drivers brake or accelerate. Wet roads often have icy bridges.
Test the traction. As soon as you pull out of your driveway, give your brakes a sharp stab and the steering wheel a yank to assess traction. AWD or stability control will fool the inattentive into thinking the roads are better than they truly are. Resample the traction regularly.
4WD equals go; not turn or stop. 4WD and AWD can only help you accelerate, they can't help you turn or stop. This is why Colorado ditches are clogged with SUVs bearing Texas plates.
Definition of "spinning your wheels": working hard to accomplish nothing. Avoid wheel spin, especially when accelerating from a stop, climbing a hill or when stuck. An exception: Snow tires offer increased traction with just a bit of wheel spin. But don't buzz 'em.
Stopping distance is drastically increased on snowy roads and braking can provoke a skid. Drive as if your brake pedal has been disconnected. If you have to brake, squeeze the pedal gently…unless you're facing an emergency.
Stomp, stay, steer. If you have antilock brakes and face an "Oh, shoot!" situation, stomp the brake pedal to the floor, stay hard on the pedal and steer around the situation. If you don't have ABS, first quickly and firmly push the brake pedal until your tires slide. Then release pressure on the pedal until your wheels start rolling. Repeat until you hit something hard. Just like the ABS computer, your goal is to get the most grip from the grippiest bits of pavement or snow. Practice these techniques before you need them!
Hope for a front-tire skid (which engineers call "understeer" and stock car drivers call "push"). Here's how to cope with a front-tire skid (which feels as if the steering shaft has broken): 1) Leave the steering wheel where it is; 2) lift off the gas; 3) say "Shtik!" or similar; 4) pray the traction returns before you get to the ditch. Turning the steering wheel more does nothing good and might do something very bad: If front traction returns suddenly, the car will dart in the direction the tires are pointing.
Rear-tire skid. If your car is on the verge of spinning out (which engineers call "oversteer" and stock car drivers call "loose") and you don't have training and practice in how to handle a rear-tire skid, repeat this phrase: "I'm screwed." For the untrained in a rear-tire skid, the best choice is to pound the brake pedal to the floor and say a prayer or an expletive, or both. No more than words alone will instruct you how to hit a curveball, nothing we can write will teach you how to catch a tailslide. The main reason: While you can successfully react to a front-tire slide, you must anticipate a rear-tire slide. Another reason: Overcorrecting is common and often tragic.更多精彩文章及讨论，请光临枫下论坛 rolia.net
VISIBILITY: Make sure you can see and can be seen. Make sure all windows, mirrors, and lights are free of frost and working. Headlights must be on when visibility is limited or when traveling Forest Service roads, and they can be useful when traveling on some of our busy 2 lane roads. Windows of vehicles that have been parked outside overnight often frost up again when the vehicle is moved.
LOOK AHEAD & DRIVE DEFENSIVELY: Watch out for other drivers and compensate for their mistakes. They may have never driven on snow before or may not have adjusted their driving for winter. Regardless of the conditions, scan up to 15 seconds or more ahead of your vehicle. Look both ways before going through intersections - even when you have the right of way. The sooner you recognize a hazard, the more time you will have to slow down and deal with it.
SLOW DOWN & INCREASE YOUR FOLLOWING DISTANCE: Adjust your speed for road conditions and visibility. With less than ideal conditions you must drive, corner, decelerate, and accelerate more slowly. Increase your following distance as road conditions and visibility get worse. For example, with compact snow and ice your following distance should be 8 to 10 seconds.
HANDLING CHARACTERISTICS: As long as you do not try to turn or brake, the tires that usually lose traction first on slick winter roads are the driven tires, the tires connected to the engine by the drive train. This is due to the torque exerted by the engine when accelerating or decelerating. A decelerating car that has lost traction to its driven wheels will usually pivot around the tires that still have traction, the tires that are not driven. The following deals only with skids that occur when decelerating with very poor traction such as compact snow and ice.
FRONT WHEEL DRIVE: Even though front wheel drive vehicles usually have more weight on the front than the rear tires, the front tires can lose traction first when traction is poor. Because you have little or no directional control when the front tires lose traction, a skidding front wheel drive vehicle can be unpredictable and difficult to control. Most of the time it will plow forward in a straight line, but sometimes the front of the car will move left or right and pivot around the rear wheels. Simply put, the car will try to go where it is pointing.
FOUR WHEEL DRIVE: Four wheel drive is the least likely vehicle to skid, because the engine's torque is divided among four wheels INSTEAD of two. The disadvantage to four wheel drive is that once a four wheel drive vehicle does skid, it is the most unpredictable and DIFFICULT to control, because all four tires usually lose traction.
REAR WHEEL DRIVE: The rear tires usually lose traction first on a rear wheel drive vehicle. Since you steer with the front tires and they are more likely to retain traction on a rear wheel drive vehicle than with the other types, a rear wheel drive vehicle is often the easiest to control during a skid. As long as the skid is not too severe and the driver keeps the front tires pointing the direction of travel, a skidding rear wheel drive vehicle will tend to pivot around the front tires and skid in a straight line.
SKID RECOVERY: Basic skid recovery procedures for all vehicle types are: 1. Never panic or give up. 2. Turn the steering wheel the direction you want the front of the car to go. 3. Do not brake or accelerate.
TURNING: Slow down prior to turning and do not accelerate until you have trade the turn. When turning use just enough-brake application to control your speed when going downhill or just enough throttle to maintain your speed going uphill. Not trying to turn and decelerate or turn and accelerate wilt provide maximum available traction and minimize the possibility of a skid.
LONG AND LOW: The longer and lower the vehicle, the safer and easier it will be to control on a slick road. Vehicles with a high center of gravity are more likely to tip over if traction improves or they hit a rut when skidding. The shorter the wheel base, the distance between the front and rear tires, the more severe the skid and the more difficult it will be to recover froth a skid.
CRUISE CONTROL: Do not use cruise control when the roads might be slick. Cruise control can apply power suddenly or at the wrong time and cause a skid or make a small skid uncontrollable. If you have the cruise control on and realize the road might be slick, use the hand operated controls to turn it off. Tapping the brakes can initiate a skid if the roads are slick.
STRANDED: Do not panic. Remember, because you have informed someone of your itinerary, they will come looking for you. If stranded, stay with the vehicle. Tie a handkerchief or flagging to your antenna and turn on your emergency flashers. Keep a downwind window partially open when running the engine for warmth and make sure the tail pipe remains clear.
<h1>This following parts are from another article.</h1>
Pay attention to the road surface. If it looks slippery, it probably is. Drivers underestimate available grip on dry and wet roads, but overestimate traction in snow and ice.
Know that traction varies. Road conditions will change from simply slushy to glare ice to just damp. A heavily traveled interstate may have plenty of grip, while its little used off-ramp is a skating rink. One place for ice to build up is where drivers brake or accelerate. Wet roads often have icy bridges.
Test the traction. As soon as you pull out of your driveway, give your brakes a sharp stab and the steering wheel a yank to assess traction. AWD or stability control will fool the inattentive into thinking the roads are better than they truly are. Resample the traction regularly.
4WD equals go; not turn or stop. 4WD and AWD can only help you accelerate, they can't help you turn or stop. This is why Colorado ditches are clogged with SUVs bearing Texas plates.
Definition of "spinning your wheels": working hard to accomplish nothing. Avoid wheel spin, especially when accelerating from a stop, climbing a hill or when stuck. An exception: Snow tires offer increased traction with just a bit of wheel spin. But don't buzz 'em.
Stopping distance is drastically increased on snowy roads and braking can provoke a skid. Drive as if your brake pedal has been disconnected. If you have to brake, squeeze the pedal gently…unless you're facing an emergency.
Stomp, stay, steer. If you have antilock brakes and face an "Oh, shoot!" situation, stomp the brake pedal to the floor, stay hard on the pedal and steer around the situation. If you don't have ABS, first quickly and firmly push the brake pedal until your tires slide. Then release pressure on the pedal until your wheels start rolling. Repeat until you hit something hard. Just like the ABS computer, your goal is to get the most grip from the grippiest bits of pavement or snow. Practice these techniques before you need them!
Hope for a front-tire skid (which engineers call "understeer" and stock car drivers call "push"). Here's how to cope with a front-tire skid (which feels as if the steering shaft has broken): 1) Leave the steering wheel where it is; 2) lift off the gas; 3) say "Shtik!" or similar; 4) pray the traction returns before you get to the ditch. Turning the steering wheel more does nothing good and might do something very bad: If front traction returns suddenly, the car will dart in the direction the tires are pointing.
Rear-tire skid. If your car is on the verge of spinning out (which engineers call "oversteer" and stock car drivers call "loose") and you don't have training and practice in how to handle a rear-tire skid, repeat this phrase: "I'm screwed." For the untrained in a rear-tire skid, the best choice is to pound the brake pedal to the floor and say a prayer or an expletive, or both. No more than words alone will instruct you how to hit a curveball, nothing we can write will teach you how to catch a tailslide. The main reason: While you can successfully react to a front-tire slide, you must anticipate a rear-tire slide. Another reason: Overcorrecting is common and often tragic.更多精彩文章及讨论，请光临枫下论坛 rolia.net