Miss this on a ticket or after a crash, and you can lose ground fast: a move that seemed minor can become key evidence that a driver broke the rules, caused a collision, or shares blame for someone's injuries. An illegal U-turn is a turn made to reverse direction where the law forbids it or where traffic conditions make it unsafe - such as at an intersection posted "No U-Turn," on a curve or hill with limited visibility, across lanes without enough clearance, or in a way that disrupts approaching traffic.

Practically, this matters because a citation for an illegal U-turn can be used to support negligence in an injury case. If a driver cuts across traffic and causes a wreck, the turn itself may become central proof of fault. In New Hampshire, fault also affects damages under the state's modified comparative negligence rule, RSA 507:7-d (2024): a person who is more than 50% at fault cannot recover damages.

New Hampshire's rules of the road in RSA chapter 265 (2024), including turning and safe-movement requirements, can make a U-turn unlawful even without a crash. After a collision on a busy road like Route 101, skid marks, vehicle positions, witness statements, and the ticket language can all matter immediately. If the crash happened while someone was working, those same facts may also surface in a workers' compensation dispute before the New Hampshire Department of Labor hearing process.