1. LASER-INDUCED ROUGHNESS- INDEX ANOMALIES IN LONGITUDINAL BOXCAR AND DRAG CONFIGURATIONS Bernard Igbafen Izevbekhai P.E. Bernard.izevbekhai@state.mn.us Minnesota Department of Transportation Transportation Research Board Conference January 2012

2. TEXTURES INVESTIGATED

3. TRIPLE LASER AND LINE (ROLINE) LASER

4. LATERAL WANDER IN BOX-CAR CONFIGURATIONS

7. VARIOUS OBSERVATIONS

11. Adjacent Lanes of the Same Cell

12. STATISTICAL ANALYSIS Mann-Whitney Wilcoxon Method of Data Comparison

13. STATISTICAL ANALYSIS Mann-Whitney Wilcoxon Method of Data Comparison

14. CONCLUSION &RECOMMENDATION The innovative grind and most recently the ultimate grind configurations are widely accepted, sought after and used because of excellent acoustic properties. To a 95% confidence level, Innovative/ Ultimate grind line and triple laser data are different The different lasers may not be used interchangeably because of sensitive textures Use line laser for acceptance testing of all Innovative grinds.