A snowstorm can quickly change driving on mountain roads from
an enjoyable adventure into a hazardous experience. Years ago, government
agencies in mountainous regions required vehicles to be equipped with tire
chains (or at least have them stored in the trunk) before the vehicle would be
allowed to begin travel through snow covered mountain passes during winter
storm periods.In the mid-1990s, Transport Canada
(Canada's counterpart to the U.S. Department of Transportation) requested a
new tire st&ard be developed to help ensure consumers could easily identify &
purchase tires designed to provide a higher level of traction in harsh winter
conditions. By the turn of the century, The U.S. Rubber Manufacturers
Association (RMA) & the Rubber Association of Canada (RAC) agreed on a
performance based st&ard to identify tires that met the severe snow service st&ards
& would be br&ed on their sidewalls with a “snowflake-on-the-mountain” symbol.
In addition to tire chains, winter tires meeting this performance st&ard are
also considered traction devices, allowing passage in many mountainous
regions. As always, when in doubt, contact area authorities to confirm local
tire chain regulations.
If tire chains are required, here are 10 basic guidelines
for their use:
- Tire chains should be installed on the drive
wheels of the vehicle following the chain manufacturer’s instructions, To
retain as much of the normal h&ling characteristics of 4WD/AWD vehicles as
possible, tire chains should be installed on all four tires, requiring the
purchase of two pairs of tire chains.
- Buy chains that are the correct size for the
tires. A proper fit is key to receiving the desired performance &
durability. Do not deflate tires to install tire chains. A correctly sized
tire chain will fit over a properly inflated tire. Additionally, because
there is typically no source of compressed air to refill a deflated tire,
driving with low tire pressure may cause permanent damage to the tire. Snow
chains may not be available for all tire sizes.
- Use only SAE Class “S” chains. The restricted
wheel well clearance in most of today's down-sized & front drive vehicles
require tire chains to operate in an envelope that is no greater than
1.46-inches vertically & .59-inches laterally around the tire. These minimum
clearances must be maintained between the tires & the vehicle’s fenders,
suspension, struts, brake lines & braces.
- It is important to pre-fit chains prior to
actual use. Being faced with the choice of either damaging their vehicle or
not completing a journey if the tire chains didn’t fit is not a choice many
drivers would want to have to make. Pre-fitting the chains will also allow
the driver to become familiar with their installation. Since tire chains
will only be required when the weather is at its worst, who would want to
learn how to install them during a blizzard?
You may want to buy a tire chain installation helper. These small ramps are
designed to prevent slipping & allow you to lay a cross chain in a
pre-formed indentation. Once you drive onto the ramp, the chains are
positioned under your tire for easier installation following the
manufacturer’s directions.
- Tire chains should always be carried in the
trunk during the appropriate times of the year & only mounted on the vehicle
when warranted by driving conditions or required by law.
For example, California’s 2003 tire chain requirements depend on the
severity of the snowstorm & are as follows:
| Requirement One
(R1): |
Snow tires or chains are required. |
| Requirement Two
(R2): |
Chains are required on all vehicles except four-wheel
drive vehicles equipped with snow tires on all four wheels. |
| Requirement Three
(R3): |
Chains are required on all vehicles, no exceptions. |
NOTE: According to
California guidelines, R1 & R2 are the most common conditions because
the highway is usually closed to traffic before an R3 condition is
imposed. |
When highway signs indicate tire chains are required, a
driver will usually have about one mile between the "Chains Required" signs
& the passage checkpoint. However, these control areas can shift rapidly
from place to place because of changing weather & road conditions.
- After initial chain installation, all of the
tire chains should be retightened after the vehicle has been slowly driven
forward or backward at least 15 feet. Failure to do so may allow the chains
to remain loose, risking damage to the vehicle & reducing chain life.
- Accelerate or decelerate slowly. Avoid spinning
or locking the wheels.
- Limit the vehicle’s speeds to within the
recommended range provided by the tire chain manufacturer.
- If a cross chain should fail, stop immediately &
make necessary repairs. Do not drive with a broken chain.
- Remove the chains as soon as the vehicle reaches
clear roads. When removing chains, drive beyond the signs reading "End Chain
Control" to a pull-off area where you can safely remove them.
While it sounds like snow chains are considered a last
resort for when the conditions get really bad, preparation before driving into
snow country in winter is important because it helps control a potentially
frustrating & tiring driving experience.