Driverless Cars

[buckeyefarmer]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

 

[3930dave]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

..... under certain conditions, but not all.......

"Although ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces, on loose gravel or snow-covered surfaces, ABS may significantly increase braking distance, while still improving steering control."

Anti-lock braking system - Wikipedia

^ That one is a double whammy - it would be bad enough if ABS matched non-ABS performance under those particular bad road conditions, but it can actually perform worse. (This consideration was the reason for the Off switch, on those ancient Audis....).

Worth considering - ABS is a relatively simple technology, compared to driverless cars.....

Rgds, D.

 

[Travelover]

I took a driving class once where we did braking with and without ABS. ABS was better, hands down.

I had a similar experience. The cars were equipped with an ABS off switch, so we could do a back to back,and we were to stop fast and steer around cones on wet asphalt. Like you, I found the ABS to be a terrific feature for the average driver. But of course, most of us are above average.

 

[3930dave]

ABS does consistently deliver better steering control to most drivers. One of the best examples is with motorcycles - too many people get to find out how easy it is to wash out the front tire, even on the street.

Best way to become familiar with the limits of a technology is under controlled track conditions.

That's all I'm trying to highlight.... all technologies have their limits of performance.... just in this tiny thread, we've had several examples of exceeding those limits. Yes, limits do move with time.

Rgds, D.

 

[Jstpssng]

..... under certain conditions, but not all.......

"Although ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces, on loose gravel or snow-covered surfaces, ABS may significantly increase braking distance, while still improving steering control."

Anti-lock braking system - Wikipedia

^ That one is a double whammy - it would be bad enough if ABS matched non-ABS performance under those particular bad road conditions, but it can actually perform worse. (This consideration was the reason for the Off switch, on those ancient Audis....).

Worth considering - ABS is a relatively simple technology, compared to driverless cars.....

Rgds, D.

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

 

[bcp]

I have about 200 feet of 4-5% grade on my driveway. On packed snow, my 2012 Tacoma, 4wd high, will travel full length from the top at about 3mph with ABS fully engaged and chattering all the way. I can stop in 4wd low, but not high.

Bruce

 

[3930dave]

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

Well said.

I get that it's hard for someone to relate to these issues, if they've never lived in serious snow country. Many a time I've used the rock/stop/roll back/repeat cycle to unstick a vehicle in snow, where the owner had already given up.

Gen I GM truck ABS was universally hated by anybody that owned them here - stopping distance in Winter was ridiculous.

When you lock up all 4 w/o ABS on deep snow or gravel, you are pushing snow/gravel ahead of all 4 wheels, dissipating a lot of energy. The vehicle continues in the same direction as when you hit the brake (great, so long as that is what you want to do) but may rotate about it's centre axis <- That's what freaks a lot of people out, and may lead to blocking an adjacent lane..... not what you want to do much of the time, but if you are on a deserted road and need to stop FAST, it can make the difference between crashing, or not.

Rgds, D.

 

[3930dave]

I have about 200 feet of 4-5% grade on my driveway. On packed snow, my 2012 Tacoma, 4wd high, will travel full length from the top at about 3mph with ABS fully engaged and chattering all the way. I can stop in 4wd low, but not high.

Bruce

Systems are less-intrusive now, and new drivers got used to ABS (as they didn't know anything else), but one of the original human-factor problems with ABS was that drivers would back off the pedal once they got force-feedback from the system.

Later partially addressed by enhanced Brake Force programming, under certain conditions.....

Rgds, D.

 

[Jstpssng]

Well said.

I get that it's hard for someone to relate to these issues, if they've never lived in serious snow country. Many a time I've used the rock/stop/roll back/repeat cycle to unstick a vehicle in snow, where the owner had already given up.

Gen I GM truck ABS was universally hated by anybody that owned them here - stopping distance in Winter was ridiculous.

When you lock up all 4 w/o ABS on deep snow or gravel, you are pushing snow/gravel ahead of all 4 wheels, dissipating a lot of energy. The vehicle continues in the same direction as when you hit the brake (great, so long as that is what you want to do) but may rotate about it's centre axis <- That's what freaks a lot of people out, and may lead to blocking an adjacent lane..... not what you want to do much of the time, but if you are on a deserted road and need to stop FAST, it can make the difference between crashing, or not.

Rgds, D.

You also learn to back off the brake when it starts to kick sideways. I've always held that the main purpose of ABS is to compensate for people who can't or won't learn proper driving techniques. Then again like so many guys when in HS, I always thought that it was fun to go into an empty parking lot and mess around in the snow; you learn a lot when your biggest concern is not going home to tell your father that you T-boned the car into a parking lot utility pole.

Systems are less-intrusive now, and new drivers got used to ABS (as they didn't know anything else), but one of the original human-factor problems with ABS was that drivers would back off the pedal once they got force-feedback from the system.

Later partially addressed by enhanced Brake Force programming, under certain conditions.....

Rgds, D.

I pulled the ABS fuses on my '98 GMC after bouncing through a washout at faster mph because the truck wouldn't stop. It cost me about $350 in front end damage.
On another occasion I came up a pitch on an unplowed road, only to find that it dropped off on the other side. I braced myself against the steering wheel and braked so hard that that I literally threw my back out while trying to stop the above mentioned F150, while rolling down the other side of the hill.
Then I had to turn around and go back again... after chaining up so that I could climb the hill.

 

[Soundguy]

I would like the ABS a lot more if it disabled itself below a certain speed. It's especially annoying when you're stuck in snow, and are slowly rocking the vehicle back and forth packing the snow. Often you will get a little movement working only to have the truck decide not to stop when you apply the brake; and you find yourself immobilized again.
I did an unscientific trial stopping from 45mph on a snow covered road in my 1998 GMC with ABS disabled, and with my (then new) 2005 F150.
First with the GMC, using the brakes judiciously to cut down through the 6" of snow; then I tried the F150 and just stomped on the brakes the way you are supposed to. The F150 travelled 50% farther before stopping. I've also seen times when one side of the truck was on snow and the other on gravel; you may as well not have brakes. Sometimes if you are in 4WD and can't stop it helps to slowly apply the parking brake; with all 4 wheels braking again it's amazing how quickly you stop. You also are at more risk of losing control though.

speaking of parking bakes, anyone remember those traction control systems? Any makers still use them? I drive an ancient 99 F350 DR. So no new tech stuff. I do like having the extra rubber on the road however..