New Jersey Speed Limits Procedures Speed limits in New Jersey are determined by a combination of state law, engineering considerations, and politics. When changes to these limits are proposed, they often encounter resistance similar to the NIMBY (Not In My Backyard) phenomenon well-known to New Jersey residents. The foundation for setting speed limits lies in state law, which establishes maximum limits such as 25 mph in school zones, business, and residential areas, 35 mph in specific low-density districts, and 55 mph or 65 mph on state highways and interstates, with 50 mph on all other roads. However, these "statutory limits" can be adjusted based on engineering studies, which follow federal guidelines. These studies take into account the flow of traffic, crash data, road layout, nearby developments, parking conditions, and pedestrian traffic. Former DOT employee Bartlett, now a project manager at Bordentown-based MBO Engineering LLC, noted that requests for speed limit red