Skid marks

**Operator13** · 07-10-06, 06:31 AM

I have a couple general questions about skid marks.

Since the advent of ABS has this made accident investigation more difficult?

Do skid marks show up on wet pavement?

Thanks,

Op13

**conalabu** · 07-10-06, 08:33 AM

How wet is wet? I had a '02 Dodge Ram 1500 leave 166' of skid mark on damp pavement a week ago, does that count?

**Jks9199** · 07-10-06, 02:06 PM

Originally Posted by Operator13

I have a couple general questions about skid marks.

Since the advent of ABS has this made accident investigation more difficult?

Do skid marks show up on wet pavement?

Thanks,

Op13

ABS will, under some conditions, leave a skid mark. It looks a lot like a skip skid or intermittent/gap skid. ABS skid marks are often really incipient or threshold skids, so they fade very rapidly, and need to be marked and photographed as soon as possible.

On wet roads, you may get a skid mark. You may also sometimes get a "squeegee mark" as the non-rotating tire forces water out of it's path. It's similar to the tire path you can sometimes see the car ahead of you leave on wet pavement. These also fade rapidly, sometimes almost immediately, especially if it's still raining.

ABS and other technical improvements have made some traditional aspects of crash reconstruction more difficult...but they've also given us new tools. Many, if not most, cars today with ABS and airbags have a black box that actually records data regarding the conditions immediately before a crash. How much and exactly what data is recorded depends on the manufacturer, and special equipment and software is required to read the data.

**Beans** · 07-10-06, 02:08 PM

I could have so much fun with this thread, but I will be the "professional" I am!

**Virginian** · 07-10-06, 02:11 PM

I had a '02 Dodge Ram 1500 leave 166' of skid mark on damp pavement a week ago, does that count?

Holy crap! What does that work out to speed-wise?

Accident investigation is some interesting stuff. I remember in the academy they were showing us speedometers where the needle had actually made a mark at the speed of the car during impact. Also saw headlight filaments that were stretched from the impact because they were on (and hot) at impact, and metal seatbelt components that were partly melted from the friction of the belt sliding through it. Nothing like seeing that stuff to make you take driving more seriously.

**Operator13** · 07-10-06, 04:05 PM

Thanks for the Replies.

On a paramedic forum I saw something that just didn't sound right, Thanks.

I didn't think about how quickly they faded. Does that depend on the type of pavement and enviromental factors?

**Jks9199** · 07-10-06, 10:57 PM

Originally Posted by beans43

I could have so much fun with this thread, but I will be the "professional" I am!

I didn't go there... but I bet Conalabu's driver had a few that weren't measured!

**Jks9199** · 07-10-06, 11:03 PM

Originally Posted by Operator13

Thanks for the Replies.

On a paramedic forum I saw something that just didn't sound right, Thanks.

I didn't think about how quickly they faded. Does that depend on the type of pavement and enviromental factors?

ABS skid marks are often incipient or threshold skid marks, since ABS's job is to keep the wheels from locking up for long. They don't last long; it'll depend on the surface, the weather, and other factors. For a long time, they said that ABS wouldn't leave any -- but I know a reconstructionist who's got some nice pics of some really long ABS marks from a cruiser wreck...

Remember, a skid mark isn't like a crayon or chalk mark of rubber that's abraded off of the tire; it's a combination of that and heating and abrasion of the road surface itself as a result of the skidding tire.

**Piggybank Cop** · 07-11-06, 12:15 AM

It’s late; I just got off, I had two glasses of wine and I can’t help myself:

If you have wet skid marks ----

Change your shorts.

**BabyGirl** · 07-11-06, 12:25 AM

You only had two before you got off?? Just messin with ya!!!!! LOL!!!!!

**TheeBadOne** · 07-11-06, 12:41 AM

Speaking of skid marks...

**Jks9199** · 07-12-06, 12:24 AM

Originally Posted by BabyGirl

You only had two before you got off?? Just messin with ya!!!!! LOL!!!!!

If they have more than two, some people find it hard to get off...

**lepdford** · 07-12-06, 12:34 AM

Originally Posted by 1sgkelly

It’s late; I just got off, I had two glasses of wine and I can’t help myself:

If you have wet skid marks ----

Change your shorts.

And there it goes.........I didn't figure it would take too long! Lol!

**CO_Cop** · 07-12-06, 11:13 PM

Originally Posted by Operator13

I have a couple general questions about skid marks.

Since the advent of ABS has this made accident investigation more difficult?

Do skid marks show up on wet pavement?

Thanks,

Op13

To answer your questions, sometimes its impossible to see any skidmarks of a vehicle with ABS if its a straight skid. ie: Rear enders. Other times, the skids are more dashed or gapped. Any others types of crashes are not too hard to figure out. Wet pavement hides the skids and they are gone quickly.

Pat

**Operator13** · 07-13-06, 06:12 AM

Originally Posted by Jks9199

Remember, a skid mark isn't like a crayon or chalk mark of rubber that's abraded off of the tire; it's a combination of that and heating and abrasion of the road surface itself as a result of the skidding tire.

Thanks again for the replies.

I thought a skid mark was like chalk or a crayon. Thanks for the clarification.