Hackettstown police are urging drivers to be aware of new school zones during certain hours.
New 20 mph speed limit signs have been installed and will be strictly enforced, police said.
The school zones are as follows:
Washington Street between Warren and Church streets; Madison Street between Church and Warren streets; Warren Street between Washington and the Hackettstown High School driveway, and Fifth Avenue from Reese to Grand avenues.
The 20 mph is in effect Monday through Friday when school is in session, during the hours of 7:30 a.m.-8:30 a.m., 12:00 p.m. - 1 p.m. and 2:30 p.m.-3:30 p.m.
During all other hours the speed limit will be 25 mph in these areas.
Police said the speed limit will be strictly enforced.