The speed limit went from 65 to 55 miles per hour between mileposts 80 and 100.
Police tell the Asbury Park Press they'll step up enforcement and write tickets from day one.
The New Jersey Turnpike Authority also plans to build shoulders, guardrails and medians along the 20-mile strip between Wall and Toms River. That stretch has seen 12 fatalities in the past five years.
