service patrols

WA-RD 221.1
Authors: 
Fred L. Mannering, Mark Hallenbeck.
Originator: 
Washington State Transportation Center (TRAC)
Publication Date: 
Friday, March 1, 1991
WA-RD 518.1
Authors: 
Jennifer Nee, Mark E. Hallenbeck.
Originator: 
Washington State Transportation Center (TRAC)
Publication Date: 
Saturday, September 1, 2001
WA-RD 518.2
Authors: 
Jennifer Nee, Mark E. Hallenbeck.
Originator: 
Washington State Transportation Center (TRAC)
Publication Date: 
Monday, March 31, 2003