Truckers making deliveries in San Francisco would laugh at other truckers
talking about a 6% hill grade as if it were worrisome. Prentiss Street
between Powhattan Ave and Chapman has a hill grade greater than 37%, San
Francisco itself is a virtual roller-coaster for drivers. Even the street
with the most curves, the famous Lombard, has a 14% grade.
Did you know that an Interstate highway with a hill grade greater than
7% is out of standards for highways designed for use by tractor-trailers
and requires a truck lane? The percentage of grade is more a discussion
for highway designers than truckers. They study weight-to-power values
in a variety of trucks, speed and distance plots, estimated performance
for tractor-trailers in various classes and tandem configurations, such
as doubles and triples to decide on an acceptable grade. A necessary question
for discussion during the design of a highway is, at what grade does a
truck’s loss of speed become worrisome enough to add a truck lane?
A truck’s lost speed on higher hill grades leads to an increase
in accidents. This also applies to vehicles towing recreational vehicles
Truckers know they must navigate those hills to deliver their load, end
of discussion. They know how worrisome and irksome driving up and down
a tricky 6% hill grade in California can be with a full load. For most,
coming down one of these is more nerve-wracking than going up. But, there
are tricks to doing both and maintaining your truck’s speed.
Going up a 6% Hill Grade
Until you become a veteran at this, going up a 6% grade can be a trying
experience, particularly with a full load. The ability of hill-climbing
for a truck depends on engine torque. The ascent It is not as harrowing
as the descent, but it will require practice before it becomes second
nature and maintaining your speed during those first few runs can be challenging.
Some may want to practice with an empty truck out there in the San Gorgonio
Pass and Coachella Valley in the Riverside and San Bernardino County areas,
though there are many other places out in Inyo, Tulare, or Kern counties.
Going down a 6% Hill Grade
There is a state-wide 55 mph speed limit restriction as prescribed by
California Vehicle Code (CVC) sections 22348-22406 for all vehicles towing a trailer and many buses, this also limits these
vehicles to the “slow lane.” Unless a local authority decides
that 55 mph is too fast for the hill grade, such as out there on I-15
through the Cajon Pass southbound, where it is posted 45 mph for truckers.
There is further clarification on that in CVC 22407, which discusses “decreasing
truck speed limit.” The code specifically discusses three axle vehicles
and gross vehicle weight, so a two-axle bobtail is exempt from the reduced
speed limit unless it exceeds the gross vehicle weight or is carrying
explosive materials, though some inexperienced sheriff’s deputies
may not see it that way and ticket you anyway.
As mentioned, going down is usually a lot more difficult and intimidating
than going up. It used to be recommended that trucker drivers descend
slowly while steadily applying the brakes, a method known as “controlled
braking.” This was based on an outdated theory, though some older
truckers still used this approach because that was what they were taught
and it is still taught in some training center.
The new recommended method is “snub braking”: 1) Select the
appropriate gear for the specific grade (this should be a lower gear),
2) allow the truck to speed up to a safe speed as it descends the hill,
3) apply the brake hard until it slows the truck in 5 mph intervals, and
4) repeat the cycle. Many manuals state that to understand how this works
to keep all the brakes cool, you must comprehend a procedure for air brakes
called, “pneumatic balance,” which evens the pounds-per-square-inch
(psi) applied to all brakes.
Why You Need Not Fear the 6% Hill Grade
Although there are those truckers who are intimidated going down a 6% hill
grade, most know it is simply a matter of applying the fundamentals in
any road conditions. After a few times, it’s likely you will learn
to navigate the hills of California by applying the fundamentals and adhering
to the CVC.
In all that you do, keep an eye on the truck’s RPMs. And, always
take road conditions, the terrain, and traffic conditions into account
when determining a safe speed, no matter what the posted speed limit.
You do all this and you’ll be right as rain driving that tractor-trailer
up and down the hills of California.
If you were ticketed for what you believe to be an unjust ticket, “going
too fast for conditions,” tailgating, or exceeding the posted speed
limit give Bigger & Harman a call, 661-349-9300. We can also correspond by email
email@example.com. Scan a copy of your ticket and send it to us along with the details surrounding
the ticket and we will reply as soon as possible with a recommended defense.
There are many DMV processes, technicalities, and circumstances that could
apply to your situation.
En español, llame al 661-349-9755.