The subways are adopting the trash rules of a wilderness area: Carry in, carry out.

MTA officials plan to remove trash cans from eight subway stops on Sept. 2 to see if forcing straphangers to take out their own trash makes the system cleaner.

Two subway stations in Manhattan and Queens have gotten a lot cleaner since the MTA removed their trash cans last fall.

Litter is down by 50 percent at the 8th Street stop on the N/R line in Greenwich Village, and by 67 percent at the Main Street 7 train stop in Flushing.

“We need to expand the experiment … to see if we have the same results,” said MTA chairman Joseph Lhota.

These subway stops will lose their trash cans for six months starting Sept. 2:

• Bronx — 238th Street 1 station and East 143rd Street 6 station

• Manhattan — 57th Street F station and Rector Street 1 station

• Brooklyn — 7th Avenue F/G station and Brighton Beach Q station

•  Queens — 111th Street A station and 65th Street M/R station

Similar programs have worked on the PATH system and on London’s Underground, Lhota said.