Nica Cave was rolling along in her wheelchair on one of Denver, Colo.'s busiest corridors — five-lane Sheridan Boulevard, headed to 17th street — in the middle of the afternoon on February 9, just inches from oncoming traffic. Cave, 25, has been using a wheelchair for most of her life due to a lifelong disability, and frequently makes journeys like this to get from A to B. But on that day, she was not alone: she was on a walk organized specifically to draw attention to the dangers experienced by people who walk and roll on Denver's streets, alongside state transportation engineers, city planners, and youth advocates curious to try it for themselves.