Anatomy of a response - I-5 at Mounts Rd

 by Claudia Bingham Baker

The tragic collision that took place on Monday, Dec. 16 on southbound Interstate 5 at Mounts Road reminds us all how fragile life is and how the status quo can change in an instant. Loss of life, injuries and property damage were the immediate results of yesterday’s collision. But the effects only started there. Most importantly, of course, were the victims, whose lives were irrevocably altered. First responders then came upon a complicated and dangerous scene. With a road strewn with debris and multiple fires burning, it was clear southbound I-5 had to close.

Thousands of motorists got caught in miles-long backups, and even people in surrounding communities were affected as they experienced floods of traffic trying to bypass the clogged highway.

It’s not often that a collision is severe enough to close an interstate for hours. Yesterday’s was. We are taking this opportunity to help explain our role in highway collisions.

Just after 10 a.m. the collision was reported. Several agencies, WSDOT included, began the simultaneous process of responding. The Washington State Patrol dispatched troopers, local fire stations dispatched fire engines and medic units, and we dispatched Incident Response crews. We also began alerting motorists via social media channels and variable-message-signs, which are the large electronic signs that span the highways and give information. Our closed-circuit TV cameras gave media and the public a first-hand look at the carnage on a freeway that had essentially closed itself from the widespread debris field and active vehicle fires. We sent highway advisories and posted the closure on our website.

Within 15 minutes of the reported collision, we had set up a detour for one lane of southbound I-5 traffic via the Mounts Road exit. Variable-message-signs as far north as the King County line and as far south as Tumwater warned motorists to avoid the area.

In responding to roadway collisions, our immediate role is to support the first responders while they care for the injured and take control of the scene. We do that by notifying the public of traffic impacts, creating detours and diverting traffic from the scene. During this incident, we performed that role while fire units extinguished the fires, Ecology responded to a fuel spill, the Washington State Patrol investigated the incident, and the deceased’s body was removed from the scene by the Pierce County Medical Examiner's Office.

We were able to open one southbound lane to traffic two hours after the incident occurred. As the day progressed, we performed as much concurrent roadway clean-up as we could, but we were unable to remove the burned semi until cleared by the responding authorities to do so.

The removal of the burned-out semi proved to be extremely difficult. The trailer was full of heavy steel. The shell, and thus the structural integrity, of the trailer was decimated by the fire. The steel cargo had to be unloaded before the trailer could be moved. Once emptied, crews used heavy equipment to start pushing the trailer onto the shoulder, but the friction reignited a fire. With the fire risk that high, crews chose to instead to remove the trailer by loading it onto a lowboy. Even then, the shell was very unstable and removal was approached deliberately and carefully to keep the trailer intact. Once the trailer was finally removed, crews cleaned and re-opened the road.

Because the road is built out of concrete pavement, rather than asphalt, the intense vehicle fires did not damage the roadway, therefore no pavement repairs were necessary.

The Dec. 16 collision at Mounts Road in Pierce County was about as difficult as highway collisions can get. It combined the challenges of multiple re-igniting fires, injuries, a fatality, tremendous amounts of debris, fuel spills, commercial and passenger vehicles, limited alternate routes, and difficult extractions from the freeway. We are sympathetic to those of you who were caught in the traffic backup. We know that while sitting in traffic, you missed important meetings and family gatherings, ran out of gas, had medical concerns and other misadventures during that very long day.

Some of you have asked us if this collision scene could have been cleared more quickly. In evaluating an event this size, the agencies involved will meet to debrief and evaluate the anatomy of the response with exactly that question in mind. Our goal is to always improve our service to the public. We will look for lessons we can apply toward that next response.