creators_name: Bierman, A. creators_name: Boyce, P. creators_name: Hunter, C. creators_name: Bullough, J. creators_name: Figueiro, M. creators_name: Conway, K. type: techreport datestamp: 2004-10-08 lastmod: 2011-03-11 08:55:42 metadata_visibility: show title: The Effect of Rise Time on the Detection of Traffic Signals ispublished: unpub subjects: psy-phys full_text_status: public keywords: light emitting diodes, visibility, reaction times abstract: The rise time of a light source is the time it takes to reach full light output after application of power. Different light sources used in traffic signals have different minimum rise times. LEDs have minimum rise times in the order of nanoseconds, while incandescent lamps have minimum rise times in the order of tens of milliseconds. Whether these rise times are achieved in practice depends on the characteristics of the power supply applied to the light source. Measurements of the rise times of actual traffic signals showed that LED traffic signals had rise times of approximately 20 ms while incandescent traffic signals had a range of rise times from 90 ms to 200 ms. This study was undertaken to determine if such dfferences in rise times influence detection of the traffic signal, measured by the reaction time to onset of the traffic signal and percentage of missed signals. date: 2000-06 date_type: published institution: Rensselaer Polytechnic Institute department: Lighting Research Center refereed: FALSE referencetext: Boff K, Lincoln J. 1988. Engineering Data Compendium. HG Armstrong Aerospace Medical Research Laboratory, Wright-Patterson AFB, OH. Bullough J, Boyce P, Bierman A, Conway K, Huang K, O'Rourke C, Hunter C, Nakata A. 1999. Luminous Intensity for Traffic Signals: A Scientific Basis for Performance Specifications. Lighting Research Center, Troy, NY. Commission Internationale de l'Eclairage. 1994. Review of the Official Recommendations of the CIE for the Colors of Signal Lights. CIE, Vienna, Austria. Institute of Transportation Engineers. 1985. Vehicle Traffic Control Signal Heads. ITE, Washington, DC. Janoff MS. 1991. Traffic signal visibility: A preliminary standard for round signal indications derived from scientific research. Transportation Research Record (1316): 5-12. Schreuder DA. 1981. Standardization of light signals for road traffic control. Transportation Research Record (811): 14-15. Teichner WH, Krebs MJ. 1972. Laws of the simple reaction time. Psychological Review 79: 344-358. citation: Bierman, A. and Boyce, P. and Hunter, C. and Bullough, J. and Figueiro, M. and Conway, K. (2000) The Effect of Rise Time on the Detection of Traffic Signals. [Departmental Technical Report] (Unpublished) document_url: http://cogprints.org/3852/1/risetime00.pdf