Traffic moving again after truck carrying liquid oxygen explodes on I-5 in Seattle

 https://www.kiro7.com/news/local/truck-carrying-chemical-tanks-burning-interstate-5/4VOY3ENAURA7FMS6VCV6NZJEPY/

Had the incident happened in a covered section of the I-5 in Seattle, things could have gotten very bad. 

https://www.king5.com/article/traffic/i-5-1-lane-mercer-truck-fire/281-598deb5e-a57b-4af2-bcab-358fece9082d

Of course any high volume traffic corridor has a potential for a big crash or a disaster.

https://komonews.com/news/local/portion-of-i-5-southbound-lanes-shut-down-between-mercer-lakeview-for-car-fire

https://mynorthwest.com/3578661/truck-carrying-liquid-oxygen-catches-fire-closes-sb-and-nb-i-5-at-mercer/

If anything like this should happen in a tunnel, it could become like a blast furnace. https://en.wikipedia.org/wiki/Freeway_Park 

https://en.wikipedia.org/wiki/Seattle_Convention_Center#Design Given as to how expensive land is, building & covering over sections of freeways has become more necessary over the years. Sometimes it's not just for new buildings, but adding new park space as well.  

There was the 1982 Caldecott_Tunnel fire in Oakland,_California. 

"The fire occurred shortly after midnight when there were few cars in the tunnel; had it occurred during normal commute hours, hundreds could have died. As a result of the fire, it is now illegal to transport hazardous material in a tanker truck through the tunnel, except between the light-traffic hours of 3:00 am and 5:00 am." https://en.wikipedia.org/wiki/Caldecott_Tunnel#Tunnel_fire 

https://en.wikipedia.org/wiki/Caldecott_Tunnel_fire#Extent_of_damage The Caldecott has become an 8 lane tunnel system in the years after the fire.

The Vista_Ridge_Tunnels in Portland have a total of 6 lanes.

https://embracesomeplace.com/living-seattle-portland 

https://thedigitallabyrinth.blogspot.com/search?q=Seattle