Speed Study Calculator

Type of Study: (using the lower value from ITE to provide greater accuracy)

Enter the distance of the segment in miles:

Enter elapsed times for each run in seconds, separated by commas (e.g., 613, 484, 662, 570):

Results

Minimum Sample Size Requirements for Travel Time and Delay Studies with a Confidence Level of 95%

Average Range in Running Speed,
R̄ (mph)
Minimum Number of Test Runs, Nᵼ, for a Permitted Error of
1.0 mph 2.0 mph 3.0 mph 4.0 mph 5.0 mph
2.5 4 3 2 2 2
5.0 8 4 3 3 2
10.0 21 8 5 4 3
15.0 38 14 8 6 5
20.0 59 21 12 8 6