The infraction or offense of speeding in a construction or work zone is committed when the driver of a motor vehicle in a marked construction/work zone exceeds the posted speed limit or exceeds the speed limit that is reasonable and prudent under the circumstances or conditions—conditions such as the road (straight, curved, wet, dry, icy, flat, hilly); the weather (clear, foggy, raining, snowing); and the visibility (smoke from a grass fire or a tractor trailer obstructing the view).

Laws vary from state to state and in many states the construction or work zone speed limit only applies when workers are present and the zone is clearly marked with signs. But drivers should be aware that the construction or work zone often extends past where barrels or other barriers have been placed on the road and the reduced speed limit continues to apply until there is a sign indicating an increased speed limit.

Laws regarding speeding in a construction or work zone (and their enforcement) vary from state to state and among cities and towns (local ordinances) and are usually located in a state’s statutes. The penalty for speeding in a construction or work zone is usually a fine and demerit points added to the driver’s license or driving record. But the fines and penalties for speeding in a construction zone are usually much greater than for a typical speeding ticket or citation—for example, fines may be doubled.

In New Hampshire, speeding in a construction or work zone is considered a serious offense. The state enforces what is known as 'work zone speed limits,' which are typically lower than the regular speed limits to ensure the safety of workers and drivers in these areas. These reduced speed limits are enforceable regardless of whether workers are present, as long as the zone is clearly marked with signs indicating the work zone and the speed limit. Drivers are expected to adjust their speed not only to the posted limits but also to the conditions of the road, weather, and visibility. Penalties for speeding in a construction or work zone in New Hampshire are more severe than for non-work zone violations. Fines are increased and may be doubled, and the offense also carries demerit points that will be added to the driver's record. It's important for drivers to be vigilant and comply with posted speed limits, especially in construction zones, to avoid these heightened penalties.