Overcrowding on the subway, derailments on commuter railroads, not to mention urgent repairs at Pennsylvania Station, are all contributing to an unpleasant summer for many travelers in and around New York City.

In this season of public transit discontent, Amandeep Saini, Alejandro Freiria and Alvin Lowe are subway foot soldiers, waging an unending and, seemingly, unwinnable battle against discarded Starbucks cups, wayward newspapers and tossed McDonalds wrappers.

The workers, assigned to clean up what riders leave behind, have a new weapon in their arsenal — two giant, battery-powered vacuums that have been deployed as part of an emergency plan that the Metropolitan Transportation Authority, which operates the subway, unveiled in response to surging delays.

The trash that commuters leave in the subway — yes, even on platform benches — often falls onto tracks. And trash catches fire. Last year, trash caused 638 rail fires.