Field evaluation of unlighted overhead guide signs using older drivers : final report, August 2003.

Details

• Creators:
  Zwahlen, Helmut T. ; Russ, Andrew ; Vatan, Sahika
• Corporate Creators:
  Ohio University. Ohio Research Institute for Transportation and the Environment. Human Factors and Ergonomics Laboratory
• Corporate Contributors:
  Ohio. Office of Traffic Engineering ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Overhead traffic signs
  • Aged drivers
  • Evaluation
  • Retroreflectivity
  • Luminaires Traffic signs and signals--Testing
• Publication/ Report Number:
  FHWA/OH-2003/015
• Resource Type:
  Tech Report
• Geographical Coverage:
  Ohio
• Edition:
  Final technical report.
• Corporate Publisher:
  Ohio Research Institute for Transportation and the Environment. Human Factors and Ergonomics Laboratory
• Abstract:
  Twenty older drivers, aged 63 to 81 (average 72.1), with corrected visual acuity ranging from 20/20 to 20/29 (average ; 20/25), evaluated six sign material and lighting combinations under nighttime conditions on US Route 30 near Mansfield, ; Ohio. The tested material combinations, all unlighted unless noted otherwise, were (legend on background) beaded Type III ; on beaded Type III, lighted beaded Type III on beaded Type III, Type VIII on microprismatic Type III, Type IX on beaded ; Type III, Type IX on Type IX, and Type VII on beaded Type III. Evaluators sat in the passenger seat and middle center ; seat of a 2002 Dodge Caravan. Headlights were kept on low beam. The evaluation loop was driven twice, once approaching ; signs in the left lane, and once approaching in the right lane. The evaluators completed questionnaires regarding sign ; visibility, legibility, and appearance after driving under each sign group and also an exit interview on the same topics at the ; end of the evaluation. ; Based on questionnaire responses, the highest rated sign groups in terms of legibility and visibility were Type IX on Type ; IX and Type VII on beaded Type III, which in the exit interview were deemed acceptable for nighttime use by 80% and 65% ; of evaluators, respectively. In contrast, the lighted beaded Type III on beaded Type III sign, representing existing signing ; practice in Ohio, was deemed acceptable by only 40-45% of evaluators. The Type VIII on microprismatic Type III sign ; performed about as well as the lighted sign group, receiving higher scores on the relevant questions on the Exit Interview ; (60% for legibility, 55% for visibility), but performing worse on the Sign Evaluation Forms. The Type IX on beaded Type ; III, a favored option in the previous study, performed noticeably still worse, and the unlighted beaded Type III on beaded ; Type III had the worst performance overall, as was the case in the previous study. ; Given that the Type IX on Type IX and Type VII on beaded Type III was clearly favored by evaluators over the lighted ; sign group, it appears that switching from lighted signs to unlighted signs using Type VII on beaded Type III or Type IX on ; Type IX materials may represent an actual improvement for older drivers, in addition to having benefits in terms of saving ; on electricity, lighting maintenance costs, and worker/traffic hazards. With the greater needs of older drivers, the use at ; short distance of Type IX on Type IX signs instead of the previously suggested Type IX on beaded Type III is ; recommended.
  More +
• Format:
  PDF
• Funding:
  State Job No. 14812(0)
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17521/dot_17521_DS1.pdf
• File Type:
  [PDF - 6.32 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:6e6751c97578c9ba4957669c68550871c712270df829c18ce7da9c1779e3882cbab79f81044c7b20d93c0e297bde170a88dcd0e3fff18e1cb71f374ec375fa99