*Article* **Striated Tire Yaw Marks—Modeling and Validation**

**Wojciech Wach \* and Jakub Z ˛ebala**

Institute of Forensic Research in Kraków, 31-033 Kraków, Poland; jzebala@ies.gov.pl **\*** Correspondence: wwach@ies.gov.pl; Tel.: +48-12-61-85-763

**Abstract:** Tire yaw marks deposited on the road surface carry a lot of information of paramount importance for the analysis of vehicle accidents. They can be used: (a) in a macro-scale for establishing the vehicle's positions and orientation as well as an estimation of the vehicle's speed at the start of yawing; (b) in a micro-scale for inferring among others things the braking or acceleration status of the wheels from the topology of the striations forming the mark. A mathematical model of how the striations will appear has been developed. The model is universal, i.e., it applies to a tire moving along any trajectory with variable curvature, and it takes into account the forces and torques which are calculated by solving a system of non-linear equations of vehicle dynamics. It was validated in the program developed by the author, in which the vehicle is represented by a 36 degree of freedom multi-body system with the TMeasy tire model. The mark-creating model shows good compliance with experimental data. It gives a deep view of the nature of striated yaw marks' formation and can be applied in any program for the simulation of vehicle dynamics with any level of simplification.

**Keywords:** yaw marks striations; tire model; multibody dynamics; vehicle accident simulation
