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:
  Aged Drivers Evaluation Luminaires Traffic Signs And Signals--Testing Overhead Traffic Signs Retroreflectivity
• 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.
  
  
• Format:
  PDF
• Funding:
  State Job No. 14812(0)
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:6e6751c97578c9ba4957669c68550871c712270df829c18ce7da9c1779e3882cbab79f81044c7b20d93c0e297bde170a88dcd0e3fff18e1cb71f374ec375fa99
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17521/dot_17521_DS1.pdf
• File Type:
  [PDF - 6.32 MB ]