Rain
The tunnel interior rains with light – a fixed bright pointillist plane that turns a dark roof into a glowing field, radiating shifting curtains of light that cascade overhead like a set of waterfalls, guiding you along the sidewalk, down along the length of the tunnel. Four programmable patterns vary the intensity and placement of points within the LED field, creating a still effect of cascading waves, responsive to both automobile movement and the time of day.
http://www.hillnow.com/2015/04/16/noma-underpass-to-get-rain-public-art-made-of-lights/
http://www.citylab.com/design/2015/04/a-dark-dc-underpass-gets-the-rain-room-treatment/390813/
https://ggwash.org/view/37914/nomas-m-street-underpass-is-turning-into-a-park-of-sorts
https://ggwash.org/view/42990/nomas-first-underpass-park-is-almost-here
https://architectenweb.nl/nieuws/artikel.aspx?ID=36663
https://ggwash.org/view/38048/nomas-underpass-project-could-spur-bike-lanes-and-gathering-space
https://www.nomaparks.org/m-street-underpass/
https://dc.curbed.com/2015/4/17/9969326/rainstorm-led-lights-noma-m-street-underpass
https://archpaper.com/2015/06/light-within-the-tunnel/
https://dcist.com/story/18/10/24/the-first-art-installation-at-the-n/
https://archpaper.com/2019/04/aiasf-awards-2019/
https://aiasf.org/architecture/design-awards/
https://www.iald.org/News/Press-Room/Winners-of-the-37th-annual-IALD-International-Ligh