Tag Archives: weigh-in-motion

On big trucks speeding and bypassing weigh stations

The in baskets: Nancy Bryant writes, “My daughter and her family have moved to Ellensburg.  During my trips back and forth from Bremerton, I have noticed that many truck drivers bypass the open weigh station heading west on I-90.  Don’t all trucks have to stop to be weighed?

“A side note,” she said, “is that it amazes me how fast those semis go. I set my cruise control at exactly the speed limit (hey, I’m retired and have no need to hurry any longer, so why go over the speed limit!!!) and basically watch as the semis pass me like I’m standing still.  Cars pass me, too, but I see an amazing number of them  pulled over later by the WSP.  I’ve never seen a semi pulled over for speeding.

The out basket: Many trucks take advantage of what’s called “weigh-in-motion,” accomplished by the sensors you see suspended over the travel lanes near the weigh stations and in-pavement sensors.

The state’s expert on the technology says, “The Weigh-In-Motion (WIM) system is part of the Electronic Screening process (E-Screening) that not only weighs the vehicle at highway speeds but also identifies the vehicle so that credentials – registration, licensed weight for haul, safety ratings for the carrier, safety values for the vehicle, etc. – can be validated before the vehicle reaches the weigh station.  This allows for a more efficient way to determine if a commercial vehicle has a potential safety issue.

“The vehicle travels over the WIM and passes by the sensors at the same time, this is how we determine if the vehicle is a commercial vehicle and whether the vehicle should report to the weigh station.  After the vehicle passes by the WIM system, there are signs that tell the driver to either ‘Report’ to or ‘Bypass’ the weigh station.

As for whether semis get stopped for speeding, I wondered if the height and length of those vehicles factor into decisions on when and whether to pull them over.

State Trooper /Russ Winger says, “We stop them all the time. They are unique in the way you mentioned, more consideration is needed for stop location and we don’t like to climb up on the cabs for obvious officer safety considerations.

“We normally have the driver contact outside the trucks after initial contact. Professional truck drivers are contacted by (commercial vehicle division) troopers on a regular basis due to inspections and weight checks as well as traffic stops for observed violations. They are usually well-versed in protocol for these contacts. It is their livelihood and they obviously wish to have their ducks in a row.”