The head of the NYPD says he’ll ride late-night subways to get a first-hand look at the quality-of-life problems straphangers face.

Commissioner Bill Bratton says he wants to stop small problems from becoming major issues.

The Daily News says he’ll be joined by “broken windows” criminologist George Kelling.

He didn’t say how often or when he’ll take the late-night rides.

Bratton says he wants to see whether the subway system again is becoming a shelter for the homeless who refuse help.

He made the announcement Tuesday at the New York City Police Foundation’s annual State of the NYPD breakfast.

Bratton headed the Transit Police in 1990 before his first tenure as NYPD commissioner in 1994. The transit police are now part of the NYPD.