As a bicyclist, this is why I stop to pick up glass bottle litter in the roadway
Broken glass bottle on 3rd Street NW on the interim route of the Metropolitan Branch Trail, adjacent to Fort Slocum Park.
There has been a fair amount of press coverage about the "new" phenomenon of "plogging," where runners pick up litter while they run.
-- "Plogging' Swedish fitness craze is coming to the US," Washington Post; "It's like jogging, but better for the environment. 'Plogging' has come to Miami," Miami Herald).
Mayor of DC Muriel Bowser even did a plogging event as part of Earth Day ("DPR Celebrates Earth Day with Citywide Plogging and More," DC DPR press release).
As a former runner, I can't see doing that because the frequent starts and stops would be hard on the body, and hard to recover from in terms of maintaining a decent pace and form while you run.
But I do pick up litter, recyclable bottles and cans mostly, while I bike. Maybe there is a preponderance of litter and it looks terrible. Or there are cans or bottles in the gutter while I am stopped at an intersection waiting for the traffic signal to change.
I tend to deposit such in residential waste recycling cans, although here and there in commercial districts there are also separate waste cans for recycling, usually painted blue, although there is a variant type in the NoMA district.
For the most part, given the number of flat tires I have experienced over the 28 years I have bicycled in DC, I almost always stop, "maintaining my pace or not," to pick up glass bottles discarded in the roadway because they will end up broken and that increases the likelihood of a flat tire for a cyclist.
… sadly, I rarely ever see other cyclists pick up litter.