Sudden Change in Momentum

As much as the absurdity of the Flyerdom can cause rankles among hockey fans, our next topic might be more universally understood, especially by regular subway commuters.

The situation: you're matriculating your way through the course of your daily commute on your local subway system, and then suddenly, the person in front of you fails to continue their forward progress down the platform, escalator or subway vehicle.
If you're properly aware and mojile ([moh-gy-el], a blend of the English words "mobile" and "agile;" for vernacular use, consult local experts T. O'Gorman or P.Johnson), you can sidestep this self-absorbed idiot and hopefully manage not to twist or sprain an ankle. If you're not so lucky, you'll plow head-on into their suspended progress. This is likely to result in a lecture from that same person on "watching where you're going" or the equivalent of the motor vehicle warning of "following too close." As if you were a mind-reader, able to predict their random acts of lunacy. For those of you who happen to encounter these unfortunate events, here's a handy reply. Or this.

High-risk locations: Smithsonian, Pentagon City, Gallery Place-Chinatown
Low-risk locations: New York Avenue, Forest Glen, West Falls Church