The Story Behind Closing the SEA Airport Drive

Monday, Nov. 27, was a bit of a unique evening for Seattle-Tacoma International Airport (SEA) with an unexpected visitor that forced the closure of the lower airport drive and resulted in a traffic backup. Because we know that many of you were impacted by the backup, we wanted to share an explanation and some photos. 

At about 5:30 p.m., a semi-truck entered the Lower/Arrivals Drive of SEA Airport. A few times each year, we do see this. Unfortunately, trailer rigs might miss the posted signage along the Airport Expressway and at the entrance to the drives and find themselves in the wrong place. Multiple signs along the way notify truckers of height limits ahead for the lower drive (12’-10”), just like you’d see for low bridges along roadways. 

The limit is due to the height of the skybridges between the airport parking garage and the main terminal. The final warning is a height bar across the entry to the lower drive. Significant damage would occur if a semi would continue forward, as a typical truck height is 13’-5”. A semi-truck can safely drive on the open air Upper/Departures drive or follow the posted signs to the over-height vehicle area and turn around their vehicle near the entrance to the airport garage.

When a truck continues on the lower drive, the driver becomes aware of the last warning when their vehicle strikes the over-height bar and they stop. The Port of Seattle Police and SEA Airport Operations teams work to close the drive, back out the rig, and re-open the drive. It usually takes 60 to 90 minutes to manage this safely.

Last Monday, this situation turned out to be more complex. This truck hit the over-height bar at full speed with the aerodynamic wind deflector; this collision bounced and bent the 1,000-pound bar, and the truck continued past the bar before stopping. The damage to the bar was so extensive it could not be removed by lifting it above the truck. 

An inspection of the structural integrity of the bar determined it would have to be removed for the safety of any traffic passing underneath. The damage was so extensive, there was a risk that the rest of the bar could snap off at any time. So the decision was made to continue to keep the drive closed until the situation was deemed safe.  

Crews then worked with the complexity of removing the damaged bar that stretched across all traffic lanes and was bent into a shape that complicated the typical process to disassemble the bar. A bucket truck and loader were needed to help with the removal.

After the bar was removed, crews were finally able to direct the truck to back out of the drive and proceed to the over-height turnaround in front of the airport garage. The drive finally re-opened about 9:40 p.m. 

We appreciate all the work by everyone involved to get the drive back to a safe and operational state for traffic. If you were a passenger impacted that night, we also appreciate your patience during this unfortunate accident in a busy period at the end of a holiday weekend.