SR 520/I 90 Active Traffic Management
http://www.wsdot.wa.gov/projects/lkwamgt/lkwaatm/
This project will install variable speed and lane control signs on SR 520 and I 90. These are very similar to the same methods used in Europe.
Variable Speed Limit Signs in Saarbruecken, Germany
Congestion Ahead Sign in Saarbruecken, Germany
Ben