Shaun
Shaun Dork
11/5/21 1:42 p.m.

As It were I was driving right through the meat of the recent 'cyclone bomb' that soaked central California.  I left Santa Cruz to get to Redding at 11 am and cars trucks and semis were sailing off into each other and whatever available ditch at an astounding rate, particularly in the central valley.  I saw at least a dozen fairly minor multi car accidents and 2-3 dozen single cars and 5 tractor trailers off in the mud by themselves.  My guess is the tractor trailers went off to avoid smashing civilians but there was a 30-40 mph south wind. There were idiots, of course-, and no doubt there were bald tires and lots of inexperienced drivers. 

The weird part was I saw several instances of late model cars and trucks go into rather violent reaction/over reaction yaw events that seemed to my eye to be happening too fast to be driver initiated.  No brake lights, just big spray as vehicle hits standing water at 50-55 mph and then short yaw changes and in a couple instances that led to the long 4 wheel drifting arc into the ditch.  I struck me that the ABS in these vehicles was making adjustments based on false information- Like a tire hydroplaning in the firmware is a tire skidding, so some adjustment is made and when traction is suddenly regained the adjustment is all wrong and the there really is a problem and its outside the physics the ABS can control.  It was extreme-  there was more standing and running water than road for long stretches.

I was in a 96 civic with no ABS but brand new conti extreme contact sport tires (the 3 or 4  groove summer tires are great rain tires) and a few hundred pounds of crap (yay!) and did not have any issues at all. Anybody familiar with the firmware in modern ABS?  Is this a know thing?          

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) MegaDork
11/5/21 4:48 p.m.

abs doesn't do anything until the driver hits the brakes hard enough to push one or more tires past mu peak.  so if you saw no brake lights you also saw no ABS intervention.

Streetwiseguy
Streetwiseguy MegaDork
11/5/21 6:41 p.m.

275/40R20.

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/5/21 6:43 p.m.

In reply to AngryCorvair (Forum Supporter) :

Maybe 'traction control' then?

Dusterbd13-michael
Dusterbd13-michael MegaDork
11/5/21 6:55 p.m.

Dads c6 z06 had traction control go haywire in the dry and pinwheeled the car down the Jersey barrier. From straight ahead at 75mph. 

It fired the Brakes to control a spin that didn't exist. 

Im suspecting similar here but from bad wheel sensor data due to water.

codrus (Forum Supporter)
codrus (Forum Supporter) PowerDork
11/5/21 7:02 p.m.

I have heard people say that cruise control can get nasty with standing water on the road.

 

dps214
dps214 Dork
11/5/21 7:46 p.m.

Traction control requires there being traction available to be controlled. If the tires are bald and you hit standing water it's going to go bad no matter how sophisticated the control systems are. Cruise control can also probably cause issues. Either a bit of a delayed reaction or I imagine like some other things with evolving technology there was a bit of a crossover period between when stability control systems started being implemented and when the engineers figured out that stability control should override cruise control.

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
11/5/21 8:24 p.m.

I'm betting stability control rather than traction control or ABS. It's probably sensing the wheel speed, yaw change and steering angle and desperately trying to compensate before going into an electronic funk that lands you in a ditch.

 

iammclovin804
iammclovin804 New Reader
11/5/21 10:19 p.m.

Traction control in my '17 Prius freaks out when I hit standing water. Not enough to cause me to lose control, but I could see it happen to someone who gets scared when unexpected things happen while driving. 

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) MegaDork
11/6/21 12:37 a.m.

The traction control might be working perfectly.  The problem isn't traction, it's the fact that your tire just encountered thousands of pounds worth of drag.  The traction control might be keeping the tire spinning at exactly the right speed, but hitting a deeper pocket of water will cause immense amounts of drag on that one corner.  No amount of traction control can help that.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
11/6/21 7:56 a.m.

In addition to what Curtis said above, that is also what it looks like if you have a broken front stabilizer link.  Things get whiplashtically yaw-uncontrolled.

 

All sorts of ways for things to go sideways.

paddygarcia
paddygarcia Reader
11/6/21 9:00 a.m.

Based on my experience growing up on the wet east coast and then moving to CA for a while I think the software error is in the drivers' brain: driving too fast for conditions and unfamiliar with how to handle those conditions.

matthewmcl
matthewmcl HalfDork
11/6/21 9:40 a.m.

Growing up in So Cal LA traffic, I learned to stay out of the number 1 lane in the rain. The drainage would be insufficient and you could hit puddle with left and not with right. Even if you hit both sides, left was deeper. A lot of cars would end up in single vehicle accidents with the concrete barrier on the left. I even saw an armored truck (bank type) high centered on a barrier.

I am not saying traction control and/or ABS are/are-not having an effect, I am just saying that even in the mid eighties, multiple cars would have problems in any heavy rain. The dynamics of a brief float and then hitting "dry" can be pretty violent if the floating initiated yaw. I flipped a motorcycle upside down on a highway doing that, once.

Shaun
Shaun Dork
11/6/21 12:57 p.m.

Thanks-  I had not thought of the traction control intervention nor the load of the water vs loss of contact with pavement (particularly on one side).  No doubt driver error is usually the deciding factor for the ditch experience, and I will venture a guess that in some cases for tractor trailers and any other vehicle one gets to choose between no good choices. I'll take from these responses that sometimes drivers aids can put a driver into a pop quiz skill test.  That is what it looked like.      

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