August 3, 2010
In Washington state, highways are getting smarter. Crews will install a series of electronic speed-limit and lane status signs over each northbound lane on Washington state’s I-5 between Boeing Access Road and I-90 in Seattle.
The high-tech signs are set to be activated on Aug. 10 to help improve safety and reduce collisions, according to the Washington State Department of Transportation (WSDOT).
This new traffic technology, also known as active traffic management (ATM) is a key element of WSDOT’s congestion relief program, “Moving Washington,” and will help manage traffic during the Alaskan Way Viaduct replacement.
“Along with strategically adding new roadway capacity and managing the demand for lane space with more commute choices, this statewide solution also uses technology and new techniques to make our highways more efficient and our transportation system better prepared for increasing traffic demands,” says the WSDOT in its press announcement about the new smarter highways.
An innovative approach
I-5 commuters will experience safer and smoother traffic on a roadway that detects changing traffic flows and automatically adapts to traffic congestion by adjusting the speed limit and providing drivers with useful traffic information.
The signs will display speed limits from 40 to 60 mph (click here for a YouTube video on Washington state’s smarter highways) , depending on traffic levels. The result will be fewer traffic collisions and less collision-related congestion.
Automatic variable speed-limit technology is the latest innovation under WSDOT’s Moving Washington program, which is using new tools to reduce congestion, improve traffic flow and manage congestion, according to WSDOT.
Safer roads mean less congestion
The project is designed to improve traffic safety and highway efficiency in one of the state’s busiest corridors. Fewer collisions mean less congestion, especially on this stretch of highway where collisions account for as much as 70 percent of congestion.
The speed-limit signs also will alert drivers with a lighted arrow to warn of an approaching lane closure and a red ‘X’ at the closed lane to better manage blocking incidents.
Drivers will see varying speed limits, alerts or even blank signs, depending on traffic conditions. Electronic signs will display traffic alerts and information, such as backups and incidents ahead and alternate route suggestions.
New highway sign technology
* WSDOT installed 15 new sign bridges, or gantries, between the Boeing Access Road and I-90 on northbound I-5.
* Sign bridges will support electronic lane status and speed-limit signs over each lane and electronic message boards that warn of backups ahead.
* Signs will be linked to traffic sensors that record traffic speed and volume used to determine the speed limit.
* The Washington State Patrol will enforce speed limits as displayed.
WSDOT crews will install other intelligent transportation system (ITS) components to improve conventional signs along the roadway. All of this technology is included in WSDOT’s smart-highways approach, widely known as active traffic management (ATM).
“The tools use information technology to make our roadways, access ramps and bridges operate as efficiently as possible,” WSDOT says on its Web site.