Wondering about the square signs over 520?

WSDOT sent me an interesting email this morning. “Smarter Highways” is a federal program that the feds are actually paying for. It’s supposed to make the system work more smoothly. I understand the State Patrol will actually enforce the speed limit on the signs, so it’s worth figuring out how they work.


WSDOT will activate Smarter Highways on northbound I-5 between Boeing Access Road and I-90 on Tuesday, August 10.

 The overhead, electronic signs will automatically alert drivers to change lanes when an incident blocks traffic ahead or to adjust their speed before they reach slower-moving traffic. It will help reduce rear-end collisions, allow for earlier escape to alternate routes and smooth lane shifting caused by incidents like stalls or collisions.

WSDOT is working with Washington State Patrol to ensure that drivers are prepared to follow the signs that will appear over each lane of traffic on sign bridges spaced about a half mile apart:

More Smarter Highways coming to Puget Sound

WSDOT is also activating Smarter Highways on the following corridors:

  • Fall 2010: SR 520 between Seattle and Bellevue
  • Spring 2011: I-90 between Seattle and Bellevue.

Funding sources

I-5 active traffic management project: This $23.8 million project is funded by the Alaskan Way Viaduct and Seawall Replacement Program to help manage the increased demand on northbound I-5 during construction. Construction activities on SR 99 (the Alaskan Way Viaduct) could start shifting demand to I-5 in the section between Boeing Field and I-90 this winter. We need to be ready to handle as much as 6,000 more vehicles per day on I-5. A smarter I-5 will help us manage that increase in demand.

SR 520/I-90 active traffic management project: This $42 million project is funded by the Federal Highways Administration Urban Partnership. This includes the construction and design for the electronic signs and sign bridges.

Moving Washington through smarter highways

Washington is one of the first states to implement cutting-edge smarter highways technology as part of its congestion-relief program, Moving Washington. Along with strategically adding new roadway capacity and managing the demand for lane space with more commute choices, this statewide solution uses technology and new techniques to make our highways more efficient.

For more information, visit: www.smarterhighways.com.

Author: Ross

I am the Director of the Department of Early Learning for Washington State. I formerly represented the 48th Legislative District in the State House of Representatives, chairing the Appropriations committee and spent many a year at Microsoft.