Abstract:
Tyre tracks can provide much more information than just the tread pattern of the tyres that created them. The relative spacing of the individual tyres in the tracks can identify details about the vehicle (e.g. make, model, year, and even sub-model). A searchable database of over 3000 vehicle specification was formed, enabling the rapid identification of any vehicle that could have formed the tracks.
Tread patterns of tyres are largely specific to a single model, allowing the details of the tyre to be established from the tracks. Their details would be useful at the beginning of the investigation, to assist with the search for the suspect vehicle. A sample tread pattern database of fifty tyres was constructed, with the ability to identify the make, model and sometimes size of the tyre from photographs of a cast or the tyre track itself. The current collection of tyre images could be expanded to form a more complete representation of the tyre selection available in New Zealand.
The continued suitability of dental stone as the standard casting compound was scrutinised. Casts were formed with several different products and their properties were compared. None of the products performed to a level that would merit the replacement of dental stone as the casting compound of choice.
Hard surfaces are not examined for tyre tracks, even though this is where the majority of present-day driving takes place. However, tyre tracks of an exceptional quality are formed on some hard surfaces, only becoming visible under ultraviolet illumination. The type of surface is the major determining factor whether or not fluorescent tracks are formed, with easily recognisable tyre tracks consistently detected on concrete and cobblestone surfaces.
