Large object hovering over roadway ~.5 mile ahead of me for 1min, then disappeared.

First saw the object through a cluster of trees while driving south on I5 in Arlington WA. The object was not moving initially. After taking exit 208 I immediately noticed it’s shape being far different than any kind of blimp, balloon, plane, or helicopter I had ever seen. At this time it began traveling to the west. Based on the size and distance I would estimate the speed to be somewhere around 30-50 mph. I took mental notes regarding its physical characteristics, and was even able to take a short video while the object was stationary. I soon lost sight of it after driving through a wooded area. As I emerged from this wooded area, the object was no longer there. Within 30 seconds of its disappearance I called my partner and told her I saw a something I could not explain. When asked to describe its shape and flight characteristics, I was unable to recall any details aside from that it was black and slightly larger than a school bus. I was certain that I would never forget the objects appearance, but after only 30 seconds I could not recall any of the specific details I had mentally noted.
Note from investigator: July 13 2023 at 3 PM witness saw a school bus size object over I-5 at exit 208, Arlington, WA.  Arlington Airport is at that exit.  Airport contacted.  Nothing to report but they keep my number to call back.
Witness unsure of characteristics and lost memory of what his saw.  He experienced no loss of time.  He made his scheduled daily appointments on time.  Object in video appears as rectangular with attachments hanging down.  Witness sent video directly to my iPhone. 
Object in this case was described the same as in this other recent NUFORC case:  https://nuforc.org/webreports/reports/176/S176437.html