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

It was criminal in this case where the owner allowed a defective truck to be operated over a steep grade.

articles.courant.com/2013-06-12/news/hc-avon-mountain-wilcox-release-0612-20130611_1_barbara-bongiovanni-dump-truck-abdulraheem-naafi

The driver in the CA crash should probably not been driving a double-bottom yet, due to inexperience.

"Singh's two trailers were fully loaded with dirt.

He said he has been a truck driver for not quite three months,"

d = V^2/(2*g*(f + G))

Where: 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.

Of course not. The driver must have been doing something recklessly negligent before it's criminal.

No way to tell how long it would take without much better data. Weight of the trailers, how many axles, condition of the pavement, condition of the vehicle, speed, angle of momentum (straight travel, curved) angle of the roadway and much more.

Even then you would come up with the best possible braking distance assuming nothing interfered.

The figure most drivers are told is that a fully loaded twin screw tractor trailer (80,000 pounds) with one two axle trailer, on level dry pavement at 55 mph takes approximately 100 yards (one football field) to stop under ideal conditions.

From the video and the articles it looks like he came around a slight curve downhill and cars were slowing/stopping in front of him. It looks like he had a single screw tractor and pulling two trailers. Couldn't tell how many axles total. It looks like he got on the brakes as soon as he could, then the trailers started to jackknife and slide down the pavement. Once that happens the driver has no control over the outcome. It strictly becomes a physics question then.

The drivers quotes will likely come back to haunt him because there will be people looking to sue or like you assign the blame solely to the driver.

What was basically said was he had too much speed for the weight he was carrying to stop in the distance that was left when he saw the cars slowing/stopped.

However they are the same things you would say if you came around a curve and found a deer standing in the road. "It was too close and I couldn't slow down enough to avoid hitting it"

The police will investigate and probably agree with the drivers statement. BUT it will then be up to them to determine if the driver actually is at fault.

Where is vehicle weight or number of tires/brakes taken into consideration ?

You ask, is it criminal? Of course it is. The driver will most likely be charged with manslaughter of some degree. He can forget about driving trucks now.

You ask, how long does it take to stop a truck? Too many factors to say for that situation. From a personal experience, hauling a single trailer, I was going down a similar hill on an interstate. At the bottom, the road turns left. I noticed the traffic had stooped and hit the brakes. I stopped within inches of the rear car. That was well over 500 feet easily.

The driver said he knew what to do and turned his rig right and aimed for the guard rail. Actually, that's a bad move, for long arm doubles. As that sets up one hell of a whip lash reaction.

For those who may not know, the driver's inexperience shows. Knowing there is a long steep grade, the first thing you do is back off the pedal and begin down shifting. There is one hill on an interstate where I will go down in a lower gear. About midway, I will stop and park it for a few minutes.

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

I believe that formula is for a car. Probably developed by some engineer who never had a driver's licemse or drove a car.

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.

You know nothing about real life. "Top Gear" did a demo of this. With just the driver, the car stopped as predicted. Add 3 passengers who all weighed over 300 pounds, it took another 100 feet to stop.

Having been a professional truck driver, it takes much longer to stop a loaded tuck. At 70mph and fully loaded, even longer.

I was told 2 to 3 times that.

Oh that's funny.

You asked what the skirting on the side of trucks was for.

I answered after a 10 second google search.

You claimed it was illegal to carry a firearm in a commercial vehicle. I proved otherwise.

Maybe you drove trucks, but it's obvious you were fired for incompetence.

This says weight was a factor

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.

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.

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.

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

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". .

You are right!!! in both cases, they ended up with a deadrat!!

Factors effecting stopping distance:

As far as stopping distance requirements:

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

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.