Talk:Skid mark

message: I would like to add some information and photos, but most importantly clarify something: Skid marks are only a subset of tire marks, that is they are caused by braking (the tire slidding). Acceleration marks are caused by accelerating, and yaw marks are caused by the tire sliding AND rotating. In other words, This article should be called "Tire Marks", and then be divided skid marks, acceleration marks, and yaw marks. This is the naming convention used by accident reconstructions, and since that is the context in which this article seems to appear, it should probably be consistent with that. Leggman7 (talk) 16:40, 20 January 2012 (UTC)
thread_title:  Comment 

message: I have added another type of skid mark to show that this article really is a serious part of trace evidence analysis. More examples from forensic specialists would be welcome. Peterlewis (talk) 23:30, 4 March 2008 (UTC)
thread_title: This is a serious topic

message: I have been working in the field of accident reconstruction and investigation for 15 years and have viewed thousands of tire marks of just about every imaginable type.  Every now and then I still see something that I did not expect to find on the roadway surface - so it is difficult to describe all skid marks as this or every tire mark as that.  There is a disagreement among traffic crash experts about what exactly causes a tire mark, and with all due respect to the authors of this entry, I must disagree with their assertion that heated bitumen has nothing to do with the creation of a tire mark.  The simple example of children skidding with their bicycle tires is misleading, completely irrelevant to the topic, and it assumes that there is only a single way in which a tire can mark a roadway surface.  It is fairly well-known and agreed upon that that tire marks on concrete are generally caused by the grinding of the tire by the rough concrete surface, which deposits small amounts of rubber and other tire materials into small voids in the concrete.  This is why airport runways must be cleaned every now and then lest their frictional characteristics become reduced by the foreign material.  It is also why marks on concrete are very short lived and will disappear within days after they are created.  (And this is why children can have their skid mark contests.)  However, asphalt is a completely different animal than is not only aggregate, tar, oil, and other materials suspended in a semi-liquid cement that holds them together, there are also various surface treatments that some asphalts are subject to after they are laid down.  Tire marks on asphalt can last for months or even a year or two if they are particularly dark and the roadway is not well traveled.  Tire marks on concrete never last so long.  Not only that, asphalt is not a singular thing that can be represented by an exemplar; rather, there are myriad types of asphalt and other composite roadway surfaces.  I am not aware that the often expressed notion that a sliding tire does not generate enough heat to smear the bitumen on the surface has been proven conclusively.  There are enough engineers and accident reconstructionists on both sides of the debate to warrant extensive study, after which I am sure they will still disagree.  Until I am presented with a verifiable and repeatable study of asphaltic concrete pavements that references more than anecdotal stories about children and their bicycles (or the many other ones I've heard), I will continue to testify that it is my expert opinion that tire marks on asphalt are created, at least in part, by the smearing of the binder (whatever that binder might be) on the surface of the roadway. 
71.110.232.239 (talk) 15:39, 24 June 2008 (UTC)
replies: text: You seem to have a lot to say on this issue. Have you ever edited the page? It seems like you could add a lot of good information. You do not have to ask permission to edit; be bold! Just make sure you cite your sources and don't include original research. TWCarlson (talk) 14:52, 30 July 2008 (UTC)
thread_title: Forensic Expert Comment