Tearing through Seattle's downtown is a massive freeway trench, and a freeway lid may help mitigate some of its issues.

Lid I5 Organization
https://lidi5.org/

Cities Aren't Loud: Cars Are Loud
   • Cities Aren't Loud: Cars Are Loud  

Timestamps:

0:00 The Problem with Urban Freeways
2:58 Why Lid a Freeway
7:10 Lid Example

Sources:

These 7 photos reveal how I5 construction tore through old Seattle
https://www.seattletimes.com/seattle...

Interstate 5 is completed in Washington on May 14, 1969.
https://www.historylink.org/File/9393

Living Near Highways and Air Pollution
https://www.lung.org/cleanair/outdoo...

Air pollution from brake dust may be as harmful as diesel exhaust on immune cells – new study
https://theconversation.com/airpollu...

Los Angeles keeps building near freeways, even though living there makes people sick
https://www.seattletimes.com/nationw...

https://www.seattletimes.com/seattle...
Here’s why I5 is such a mess in Seattle area, and what keeps us moving at all

I5 Lid Feasibility Study
https://www.seattle.gov/opcd/ongoing...

8 Takeaways from Seattle's Lid I5 Feasibility Study
https://www.theurbanist.org/2021/01/2...

Lidding I5 Declared “Technically Feasible” by Consultant Team
https://www.theurbanist.org/2019/09/2...

Viral video documents string of crashes at downtown Seattle intersection
   • Viral video documents string of crash...  

Seattle City Council supports I5 lid project
   • Seattle City Council supports I5 lid...