Slippery when wet? Driving in the rain

Safety
21

Road and tire technology won’t save you when you go too fast.
How’s that?

3 Likes
22

When my daughter, now 17, was just learning, we talked a lot about new rain on an oily asphalt surface as we were driving to Denny’s for the family dinner . I was driving and attempting to show her the different technique . . but it may not have sunk in all the way . .just words to try to remember later.

    • until - -
      We got to Denny’s and parked . .in their asphalt parking lot . . and she . .being the first out of the truck . .BOUNDED out to race her brothers to the door.
    • her very first step on that asphalt ?
      zzzzzzzzzzzzzzzzzZIP ! ! ! right on her butt on the wet pavement.
      BAM !

The perfect learning example and at exactly the right time too.

‘’ THAT is how the TRUCK feels on the roadway too.’’ I told her.

Lesson learned.

4 Likes
23

Well summarized, circuitsmith.

24

That’s actually a very good point. That hydraulic wedge under the front part of the tire’s footprint always supports a percentage of the vehicle’s weight. The faster you go, the bigger the hydraulic wedge becomes and the greater percentage of the vehicle’s weight is supported by that hydraulic wedge.
I have driven in hard rain and found going faster than around 50 mph up a grade impossible because of wheelspin, in fifth gear, with the power of a one liter three cylinder engine of a Geo Metro. I could still steer but I didn’t have enough traction to accelerate more.
Hydroplaning itself actually slows down your car dramatically. It takes a lot of power to accelerate all that water so it can get out of your way. It’s why you get bad gas mileage in a downpour, although the slow speeds traffic moves does offset that a little bit.

25

Thanks, BLE - I intend to steal that explanation!

26

Yep, agree with Ken. Oils accumulate on the road during dry times so the most dangerous time is when it just starts to rain after a dry spell.

27

Be smart on wet pavement? Sorry 37 seconds in is the fun. never mind better link

1 Like
28

I’ve seen that video… I think the water was only a small part in the problem. The more serious problem is the hot-wax feature of the car wash. That waxy residue coats the pavement and makes it very slippery when wet… and its always wet when running. We had a car wash like this in when I lived in Ohio withOUT the ledge to fall off of! The turn out of the place was always slicker that even wet pavement.

29

The under carriage wash was no charge in that case!

1 Like
30

Nice guys that ran out to take a video but didn’t bother to offer any help. Really though there should have been a guard rail of some kind.

1 Like
31

Posting to YouTube is apparently more important that helping someone in an inverted car… :rage:

32

Te pedestrian looking over the edge + the pickup truck could have been another disaster.

33

The video appears to me to be footage from a security camera. You’ll notice the aim and field of view never move at all.

1 Like
34

A “curve” that allows 70mph is not a curve.

1 Like
35

I don’t think that car skidded over the edge did it? It appeared just to be driven over the edge. The driver wasn’t paying att’n or couldn’t see clearly out the windshield maybe. That looks like a good place to install some safety railings.

36

Sorry, but that is absolutely wrong. The highway system, as designed, has curves with a banked roadway that allowed the car to negotiate that curve at speed with less steering input than a road with no banking. The radius of curvature may be large but it is still a curve. Lateral G’s were offset by the bank angle to allow a car or truck to safely continue at speed.

Exactly the same is done with railway design. The tracks are banked to reduce the lateral loads on the rails in a curve as well as the flanged wheels on a rail car, to increase the tip-over speed and reduce the need to slow for a curve.

2 Likes
37

It’s done on racetracks too. :grin:

1 Like
38

“Allows 70mph” needs some clarification.

http://www.sportrider.com/sites/sportrider.com/files/styles/large_1x_/public/motogp-marquez-gives-opinion-on-lead.jpg?itok=yvvPuLcr&fc=50,50

1 Like
39

Those banked curves on the interstate are nice until you’ve got glare ice. Then you’d much rather have a flat surface.

Yeah I know the camera was from a fixed point but the first guy that showed up had what looked like a camera up to his face, more interested in getting a good shot of the event than offering any assistance. Then the second guy just joined the first guy gawking. Friends like that . . .

40

Interesting point. I have, on more than one occasion over the years, been going slowly in a terrible storm and begun to slide down into the curve, the curve having been designed for much higher speeds. Aircraft experience the same phenomena as a normal part of flight, but they have rudders to compensate. Oddly, it’s been so many decades that I cannot remember for sure whether falling into the curve is a “slip” or a “slide”!!! My mind is losing all my old knowledge!