SAMPLE SIZE DETERMINATION FOR TRAVEL TIME AND DELAY STUDIES

Based on the central-limit theorem, sample means of travel times are assumed to have a normal distribution, regardless of the actual distribution of the population of travel times along a study route. Using this assumption, the techniques of statistical quality control are applied to provide a procedure for sample size determination. This procedure is applicable for both the license-plate and the test car techniques; it is also used for estimation of sample sizes for travel time and delay studies that involve either general travel conditions for all vehicles along a study route, or for only public transportation vehicles on scheduled routes.

• Corporate Authors:

  Institute of Traffic Engineers

  2029 K Street, NW
  Washington, DC    20006
• Authors:
  • Oppenlander, J C
• Publication Date: 1976-9

Media Info

• Features: Photos; References; Tables;
• Pagination: p. 25-28
• Serial:
  • Traffic Engineering
  • Volume: 46
  • Issue Number: 9
  • Publisher: Institute of Traffic Engineers

Subject/Index Terms

• TRT Terms: License plates; Motor vehicles; Public transit; Routes; Statistical quality control; Traffic delays; Travel time
• Subject Areas: Highways; Operations and Traffic Management; Public Transportation;

Filing Info

• Accession Number: 00141662
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 15 1981 12:00AM