Evaluation of the Benefits of Reflectorized Sign Posts to Drivers

Year 2013, Volume: 19 Issue: 3, 112 - 116, 01.03.2013

Erdinç Öner

Abstract

In United States Federal Highway Administration (FHWA) provides departments of transportation (DOTs) the option of using retroreflective material on sign posts when the DOTs determine that there is a need to draw attention to the sign, especially at night. The State of Ohio Department of Transportation (ODOT) required all Stop, Yield, Do Not Enter, and Wrong Way sign posts to be reflectorized with RED reflective sheeting material and all Chevron, Stop Ahead, and One/Two Large Directional Arrow sign posts to be reflectorized with YELLOW (sign background color) reflective sheeting material as part of ODOT Comprehensive Highway Safety Plan and FHWA' recommendations.In this study, a photometric analysis and a human factors analysis were conducted to estimate the benefits of reflectorized sign posts to driver visual perception, driver guidance and driver comprehension. The study showed that the reflectorized sign posts improve detection, recognition, and comprehension of traffic signs for drivers, especially in nighttime driving conditions.

Keywords

Traffic sign, Reflectivity, Human factors, Photometric analysis.

Trafik İşareti Direklerinde Kullanılan Reflektif Malzemelerin Sürücüler için Faydalarının İncelenmesi

Abstract

Amerika Birleşik Devletleri Federal Karayolları İdaresi, trafik işaretlerinin özellikle gece görülebilirliğini artırmak ve dikkat çekmek için trafik işareti direklerinde reflektif malzemelerin kullanılabilceğini belirtmektedir. Bu öneri doğrultusunda Ohio Eyaleti Ulaştırma Bölümü karayolları güvenliğini artırmak için tüm Dur, Yol Ver, Girilmez ve Yanlış Yön trafik işareti direklerinin kırmızı reflektif malzeme ile kaplanmasına ve tüm ok işaretli yön levhalarının gövdelerinin ise sarı reflektif malzeme ile kaplanmasına karar vermiştir.Bu çalışmada, trafik işareti direklerinde kullanılan reflektif malzemelerin fotometrik analizi ve insan faktörleri analizi yapılmıştır. Bu analizler sonucunda trafik işareti direklerinde reflektif malzeme kullanımının sürücülerin trafik işaretlerini algılamasına, tanımasına ve anlamasına olan faydaları incelenmiştir. Çalışma sonucunda reflektörlü işaret direkleri, özellikle gece sürüş koşullarında, sürücülerin trafik işaretlerini algılamasına, tanımasına ve anlamasına faydasının olduğu görülmüştür.

Keywords

Trafik işaretleri, Reflektivite, İnsan faktörleri, Fotometrik analiz.

References

• Traffic Engineering Department, Ohio Department of Transportation, Sign Design Manual, October 20, 2006 Revision.
• Zwahlen, H.T. and Schnell, T., "Evaluation of the Buckeye Cross buck at Public, Passive Railroad/ Highway Grade Crossings in Ohio", Final report prepared for the Ohio Department of Transportation, 55 pages, 2000.
• Zwahlen, H.T. and Schnell, T., “Curve Warning Systems and the Delineation of Curves with Curve Delineation Devices,” Published in Proceedings of the Conference Road Safety in Europe and Strategic Highway Research Program (SHRP), No. 4A, Part 5, 1996, pp. 8-22.
• Zwahlen, H. T., “Warning Signs and Advisory Speed Signs – Reevaluation of Practice”, Final report prepared for the Ohio Department of Transportation, 185 pages, 1983.
• Schnell, T. and Zwahlen, H.T., “Visibility of Rectangular Targets as a Function of Length and Width” Proceedings of the Human Factors and Ergonomics Society 43rd Annual Meeting, Houston, Texas, 1999, pp. 1338-1342.
• Zwahlen, H.T., Miller, M., Mohammad, K., and Dunn, R., “Optimization of Post Delineator Placement from a Visibility Point of View”, Transportation Research Record, 1172, pp. 78-87, 1988.
• Zwahlen, H. T., and Schnell, T., “Evaluation of Two New Crossbuck Designs for Passive Highway-Railroad Grade Crossings”, Transportation Research Record, 1694, pp. 82-93, 1998.
• Stalder, H.I. and Lauer A.R., “Effective Use of Reflectorized Materials on Railroad Boxcars”, Highway Research Board Bulletin, 89, pp. 70-75, 1954.
• Lauer, A. R., and Suhr V.R., “An Experimental Study of Four Methods of Reflectorizing Railway Boxcars”, Highway Research Board Bulletin, 146, pp. 45-50, 1956.
• Schnell, T., User Manual for the Target Visibility Predictor (TARVIP) Computer Model, Operator Performance Laboratory and the Center for Computer Aided Design of University of Iowa, Iowa City, IA, 2004.
• Zwahlen, H.T. and Schnell, T., “Driver-headlamp Dimensions, Driver Characteristics, Vehicle and Environmental Factors used in Retro-reflective Target Visibility Calculations”, Transportation Research Record, 1692, pp. 106-118, 1999.
• Schoettle, B., Sivak, M., and Flannagan, M.J., “High-Beam and Low-Beam Headlighting Patterns in the U.S. and Europe at the Turn of the Millennium”, The University of Michigan Transportation Research Institute, 2001.
• Carroll, A.A., Multer J., Williams D., and Yaffee M.A., “Freight Car Reflectorization”, Final Report, Washington, D.C., U.S. Department of Transportation, Federal Railroad Administration, Office of Research and Development., 1999.
• Zwahlen, H.T. and Yu, J., “Color-shape Recognition of Reflectorized Targets Under Automobile Lowbeam Illumination at Night”, Transportation Research Record, 1327, pp. 1-7, 1991.
• “How Retroreflectivity Makes Our Roads Safer: Night Lights, Lighting the Way”, US Department of Transportation, Federal Highway Administration, 2005.