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Tuesday, August 11, 2026, 8:52 PM
Site: Work Zone Safety Training
Course: Work Zone Safety Training (HOME)
Glossary: WZSC Glossary
1

15th percentile speed

the speed at or below which 15 percent of vehicles travel. Also, see Speed distribution.

8

85th-Percentile Speed

The speed at or below which 85 percent of the motor vehicles travel. Also, see Speed distribution.

MUTCD 2009 Edition with May 2012 Revisions 1 and 2