TURNOUTS: SUMMARY REPORT. TRAFFIC OPERATIONAL REPORT NOS. 1 AND 2

Operational data was collected at eight turnouts along two lane roads in the mountains of northern and central California during the summer of 1976. It was found that about 10 to 12% of all drivers with one or more followers used any given properly designed turnout along moderate-volume roads (AADT of 1,000 to 4,000 vehicles). The length of turnouts can vary widely. Total lengths (including entry and exit tapers) of about 200 to 250 feet appear best for low speed roads (30 mph or less), and about 400 to 450 feet appears best for high speed roads (50 mph or greater). Turnouts shorter than these lengths are generally safe, but may receive relatively little use. Paved widths of 9 to 12 feet were adequate along cut slopes, and paved widths of about 16 feet were adequate on fill slopes. Safety data was obtained by analyzing sixteen turnouts. There was approximately one accident for every 80,000 vehicles using the turnouts. In summary, a series of turnouts can reduce delay considerably, and properly designed turnouts are safe. /Author/SRIS/

Media Info

  • Features: Figures; Tables;
  • Pagination: 92 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00153856
  • Record Type: Publication
  • Source Agency: National Safety Council Safety Research Info Serv
  • Files: TRIS, STATEDOT
  • Created Date: Sep 28 1977 12:00AM