Police officers in Manhattan will no longer arrest most people who commit minor offenses like urinating in public and riding between subway cars under a policy shift announced on Tuesday that officials hope will help to reduce a backlog of cases pending in Criminal Court.

The joint decision by the Police Department and the Manhattan district attorney, Cyrus R. Vance Jr., will take effect on Monday. Under the new policy, officers will issue criminal summonses for such offenses rather than making arrests except when they determine an offender poses a threat to public safety.

The changes apply to minor offenses like drinking alcohol in public, taking up two seats on the subway or putting one’s feet on the seats. Officials estimate the changes will result in about 10,000 fewer cases being prosecuted in Manhattan Criminal Court each year, freeing up police officers, prosecutors and the court to focus on more serious crimes.

Summonses are adjudicated by judges, who ask the recipient questions about the alleged violation or infraction before deciding whether to dismiss the ticket or impose a penalty, usually a fine. The process is typically simpler and faster than prosecuting an arrest, which requires officers and prosecutors to spend hours processing a suspect, filing paperwork, building a case and showing up for court appearances.