Chicago eL

 https://interactive.wttw.com/chicago-by-l/sidetracks/history-l , https://www.youtube.com/watch?v=7NPCFnF4csA

https://www.947wls.com/2022/02/28/this-is-where-the-cta-el-train-is-its-loudest/

https://www.chicagotribune.com/news/ct-chicago-cta-train-noise-0225-20220226-yhn4xqgtsnaljlnqe3viao53nq-story.html

https://interactive.wttw.com/chicago-by-l/sidetracks/how-cta-map-got-its-colors

https://www.youtube.com/watch?v=n6xJFpPY_7s&t=2019s CTA 

https://www.youtube.com/watch?v=sLti1BiNCPE OH

https://www.youtube.com/watch?v=PIUFbPNh-tE

https://www.youtube.com/watch?v=xzccefMyWGw not blue