Approach to Determine Slip Values Based on the Intensity of Tire Marks with Respect to Tire and Road Properties 2013-01-0781

The objective of the presented research is to analyze the cause-and-effect chain of the emergence of tire marks and to indentify how the intensity of a friction-related tire mark on asphalt or concrete pavements can provide additional information related to forces or slips at the marking wheels. Focusing on tire marks due to abrasive wear, the influences on the intensity of tire marks are analyzed based on three categories: vehicle dynamic parameters, tire and road properties, which determine the sensitivity of tire marking for a specific tire-road combination for constant vehicle dynamic parameters; and optical parameters, influencing the contrast of a given tire mark. The analysis includes a new objective method for the assessment of the tire mark intensities derived by photos of tire marks, generated with a tire measurement trailer. Additionally a test rig was developed to determine the tire marking sensitivity with reference marks under controlled friction conditions. By comparing the intensities of the real tire mark with the intensities of the reference marks, it is possible to determine the slip under which the tire mark was produced and to compare it with the measured values from the trailer. The results show that the presented method principally allows a determination of tire slip values from the intensities of visible tire marks within a certain scattering range. The new approach contributes to a more detailed visualization of tire mark intensities in accident reconstruction tools as a function of tire slip and vehicle dynamic values during accident scenarios.