How long does it take a truck to stop & is it criminal if he doesn't?

On Fri, 11 Jul 2014 19:30:48 -0500, Unquestionably Confused wrote:

>> Where is vehicle weight or number of tires/brakes taken into
>> consideration ?
> It isn't as it's immaterial. Two identical trucks, with the same tires,
> driving the same speed, traveling on the same pavement will stop in the
> same distance regardless of one being filled with concrete and the other
> empty.

This says weight was a factor
http://activerain.trulia.com/blogsvi...nd-11-injuries

On 7/11/14 3:48 PM, Retired wrote:
> On 7/11/14, 4:25 PM, deadrat wrote:
>> On 7/11/14 2:33 PM, Ann Marie Brest wrote:
>>> What distance does a sand truck take to slow down on a 6% grade?
>>
>> d = V^2/(2*g*(f + G))
>>
>> Whe
>> d = Braking Distance (ft)
>> g = Acceleration due to gravity (32.2 ft/sec2)
>> G = Roadway grade as a percentage
>> V = Initial vehicle speed (ft/sec)
>> f = Coefficient of friction between the tires and the roadway
>>
>> So if the truck were going 55mph, that would be about 80 feet per second.
>>
>> The coefficient of friction for treaded tires is about .7 on dry roads.
>>
>> d = (80*80)/(2*32*(.7+.06))
>>
>> or about 132 feet (from the time the driver hits the brakes).
>> Assuming a lot of things, like the brakes don't burn out.
>>
>>> If it can't stop in that distance, is it criminal?
>>
>> Of course not. The driver must have been doing something recklessly
>> negligent before it's criminal.
>>
>> <snip/>
>>
>
> Where is vehicle weight or number of tires/brakes taken into
> consideration ?

The vehicle weight (actually its mass) makes no difference as Galileo
showed when he dropped a Mack truck and a VW beetle from the Leaning
Tower of Pisa.

On Fri, 11 Jul 2014 12:33:01 -0700, Ann Marie Brest
> wrote:

>What distance does a sand truck take to slow down on a 6% grade?
>If it can't stop in that distance, is it criminal?
>http://www.ktvu.com/news/news/local/...hway-17/ngcnY/
>
>This accident yesterday blocked the highway for 10 hours, with the CHP
>saying it was a crime scene where one person died.
>http://www.mercurynews.com/bay-area-...hbound-highway
>
>The driver is quoted in that article as saying he had too much speed with
>too much weight with too little distance.
>
>How long does it take a truck to stop & is it criminal if it doesn't stop
>in that distance?
I can't say how long it takes to stop without knowing the weight of
the truck, what kind of brakes, what pavement condition, etc. However,
if the driver, by operating an overloaded vehicle at too high a speed
with inadequate brakes, and following too closely to allow a safe
stopping distance can be considered to be driving carelessly - which
can easily be argued, it IS a criminal offence.
If someone died from his carelessnes it is arguably vehicular
manslaughter - or at the very least careless driving causing death. I
believe both of these (at least in Canada - don't know about
California) are criminal code violations.
I would not want to be in the driver's shoes trying to fight the
charge in court.

On 7/11/2014 8:30 PM, Unquestionably Confused wrote:
> On 7/11/2014 3:48 PM, Retired wrote:
>>
>> Where is vehicle weight or number of tires/brakes taken into
>> consideration ?
>
>
> It isn't as it's immaterial. Two identical trucks, with the same tires,
> driving the same speed, traveling on the same pavement will stop in the
> same distance regardless of one being filled with concrete and the other
> empty.

Someday, I'll pilot an empty, and you take a truck
full of gravel, and we'll try it. Not that I've driven
truck, but the vehicles I've driven, it's different.

--
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

richard wrote:

> On I-17 in Arizona, I will go through the mountains at 45mph downhill.

You're no fun. Just let it roll; you'll be going slow enough on the grade
south of Camp Verde.

On Fri, 11 Jul 2014 19:30:48 -0500, Unquestionably Confused
> wrote:

>On 7/11/2014 3:48 PM, Retired wrote:
>> On 7/11/14, 4:25 PM, deadrat wrote:
>>> On 7/11/14 2:33 PM, Ann Marie Brest wrote:
>>>> What distance does a sand truck take to slow down on a 6% grade?
>>>
>>> d = V^2/(2*g*(f + G))
>>>
>>> Whe
>>> d = Braking Distance (ft)
>>> g = Acceleration due to gravity (32.2 ft/sec2)
>>> G = Roadway grade as a percentage
>>> V = Initial vehicle speed (ft/sec)
>>> f = Coefficient of friction between the tires and the roadway
>>>
>>> So if the truck were going 55mph, that would be about 80 feet per second.
>>>
>>> The coefficient of friction for treaded tires is about .7 on dry roads.
>>>
>>> d = (80*80)/(2*32*(.7+.06))
>>>
>>> or about 132 feet (from the time the driver hits the brakes).
>>> Assuming a lot of things, like the brakes don't burn out.
>>>
>>>> If it can't stop in that distance, is it criminal?
>>>
>>> Of course not. The driver must have been doing something recklessly
>>> negligent before it's criminal.
>>>
>>> <snip/>
>>>
>>
>> Where is vehicle weight or number of tires/brakes taken into
>> consideration ?
>
>
>It isn't as it's immaterial. Two identical trucks, with the same tires,
>driving the same speed, traveling on the same pavement will stop in the
>same distance regardless of one being filled with concrete and the other
>empty.
Tell that to a proffessional truck driver. The difference in load,
brake swept area (number of brakes/tires) will both affect stopping
distance significantly.
It takes just as much horsepower to accellerate a load from a stop to
60MPH up a hill in a given time or distance as it does to slow the
truck from 60MPH to a stop down the same hill. If you double the
weight, it will take a lot more time/distance or a lot more horsepower
to accellerate the load up the hill - and the same amount more
horsepower to stop the truck. That horsepower is absorbed by the
brakes when slowing the load, turning it all to heat. The more brakes,
the more friction area, and the better the heat dissipation, all else
being the same. The hotter the brakes get, the less braking force they
can exert due to thermal brake fade (a complete discussion topic on
its own)
Now the size and number of tires on those braked axles also makes a
difference, because if the brakes run out of friction before the
tires, the brakes limit the stopping distance. If the tires run out of
traction before the brakes, the tires slide. The coefficient of
friction of a hot tire sliding on asphalt is significantly different
than the coefficient of friction between a warm rolling tire of the
same size and the same asphalt. That is a large part of the reason for
antilock brakes. Tires braked at the limit of adhesion stop a LOT
faster (and with more control) than a sliding locked tire. This is
true of almost any road surface.

Now, If the truck has more than adequate brakes, and more than
adequate tire for the job, the difference in weight won't matter much.
If on the other hand the truck has adequate tires and brakes to handle
stopping 40 tons from 60MPH to a dead stop in 600 feet on a 6% grade,
he is NOT going to stop 60 tons in the same distance on the same
grade, just as it will not stop 40 tons in the same distance on a 12%
grade.

The question if it is criminal if he cannot get stopped hinges on
several factors.
Was the truck loaded within it's GVW rating? If it was overloaded, the
driver is on thin ice.
Was the driver driving within the posted speed limit? If not, again,
he is on thin ice.
Was the truck in sound mechanical condition? If not both the driver
and owner are now in trouble.
Were the air brakes in adjustment, and was the brake check logged in
the log book? If not, again the driver is on thin ice.

If the question of whether a prudent driver would have approached that
hill at the speed he approached it -even if it was within the speed
limit is no, the driver is on thin ice.

It appears limitted driving experience was a major factor in the
accident. Unfamiliarity with the road may also have contributed - but
if any of the above questions get a "no" answer - - - - .

"Sometimes when you are on thin ice you end up in hot water".
..

On Fri, 11 Jul 2014 21:54:09 -0500, deadrat > wrote:

>On 7/11/14 3:48 PM, Retired wrote:
>> On 7/11/14, 4:25 PM, deadrat wrote:
>>> On 7/11/14 2:33 PM, Ann Marie Brest wrote:
>>>> What distance does a sand truck take to slow down on a 6% grade?
>>>
>>> d = V^2/(2*g*(f + G))
>>>
>>> Whe
>>> d = Braking Distance (ft)
>>> g = Acceleration due to gravity (32.2 ft/sec2)
>>> G = Roadway grade as a percentage
>>> V = Initial vehicle speed (ft/sec)
>>> f = Coefficient of friction between the tires and the roadway
>>>
>>> So if the truck were going 55mph, that would be about 80 feet per second.
>>>
>>> The coefficient of friction for treaded tires is about .7 on dry roads.
>>>
>>> d = (80*80)/(2*32*(.7+.06))
>>>
>>> or about 132 feet (from the time the driver hits the brakes).
>>> Assuming a lot of things, like the brakes don't burn out.
>>>
>>>> If it can't stop in that distance, is it criminal?
>>>
>>> Of course not. The driver must have been doing something recklessly
>>> negligent before it's criminal.
>>>
>>> <snip/>
>>>
>>
>> Where is vehicle weight or number of tires/brakes taken into
>> consideration ?
>
>The vehicle weight (actually its mass) makes no difference as Galileo
>showed when he dropped a Mack truck and a VW beetle from the Leaning
>Tower of Pisa.
You are right!!! in both cases, they ended up with a deadrat!!

Unquestionably Confused wrote:

> It isn't as it's immaterial. Two identical trucks, with the same tires,
> driving the same speed, traveling on the same pavement will stop in the
> same distance regardless of one being filled with concrete and the other
> empty.

Factors effecting stopping distance:

http://www.crashforensics.com/truckc...nstruction.cfm

As far as stopping distance requirements:

http://www.ttnews.com/articles/baset...?storyid=22391

It may have changed, but when I took the CDL test, the official view was an
empty truck would take longer to stop.

On Fri, 11 Jul 2014 15:25:56 -0500, deadrat > wrote:

>On 7/11/14 2:33 PM, Ann Marie Brest wrote:
>> What distance does a sand truck take to slow down on a 6% grade?
>
>d = V^2/(2*g*(f + G))
>
>Whe
>d = Braking Distance (ft)
>g = Acceleration due to gravity (32.2 ft/sec2)
>G = Roadway grade as a percentage
>V = Initial vehicle speed (ft/sec)
>f = Coefficient of friction between the tires and the roadway
>
>So if the truck were going 55mph, that would be about 80 feet per second.
>
>The coefficient of friction for treaded tires is about .7 on dry roads.
>
>d = (80*80)/(2*32*(.7+.06))
>
>or about 132 feet (from the time the driver hits the brakes). Assuming
>a lot of things, like the brakes don't burn out.
>
>> If it can't stop in that distance, is it criminal?
>
>Of course not. The driver must have been doing something recklessly
>negligent before it's criminal.
>
><snip/>


He was going downhill so you have the sign wrong, it should be f-G for
this case. That's not a big difference and not your major error. Your
major error is thinking that truck tires and truck brakes will come
close to the maximum available surface friction of the pavement. For
estimating purposes a more realistic effective coefficient of friction
would be 0.50. Crunching those numbers gives you around 230 feet.

On Fri, 11 Jul 2014 19:30:48 -0500, Unquestionably Confused
> wrote:

>On 7/11/2014 3:48 PM, Retired wrote:
>> On 7/11/14, 4:25 PM, deadrat wrote:
>>> On 7/11/14 2:33 PM, Ann Marie Brest wrote:
>>>> What distance does a sand truck take to slow down on a 6% grade?
>>>
>>> d = V^2/(2*g*(f + G))
>>>
>>> Whe
>>> d = Braking Distance (ft)
>>> g = Acceleration due to gravity (32.2 ft/sec2)
>>> G = Roadway grade as a percentage
>>> V = Initial vehicle speed (ft/sec)
>>> f = Coefficient of friction between the tires and the roadway
>>>
>>> So if the truck were going 55mph, that would be about 80 feet per second.
>>>
>>> The coefficient of friction for treaded tires is about .7 on dry roads.
>>>
>>> d = (80*80)/(2*32*(.7+.06))
>>>
>>> or about 132 feet (from the time the driver hits the brakes).
>>> Assuming a lot of things, like the brakes don't burn out.
>>>
>>>> If it can't stop in that distance, is it criminal?
>>>
>>> Of course not. The driver must have been doing something recklessly
>>> negligent before it's criminal.
>>>
>>> <snip/>
>>>
>>
>> Where is vehicle weight or number of tires/brakes taken into
>> consideration ?
>
>
>It isn't as it's immaterial. Two identical trucks, with the same tires,
>driving the same speed, traveling on the same pavement will stop in the
>same distance regardless of one being filled with concrete and the other
>empty.

In the real world it would not be immaterial. The empty truck with
it's 120psi tires and stiff springs would most likely "bounce" around
if the wheels locked which would greatly increase the stopping
distance. OTOH, a fully loaded truck might not even be able to come
close to locking all the tires or even doing a good job of "braking"
them so it too could have long stopping distances. But it extremely
unlikely the stopping distances would be the same, in the real world.