In New Zealand, the maximum speed limit for cars and motorcycles on open roads is 100 kilometers per hour. This regulation is designed to ensure the safety of drivers, passengers, and other road users, while taking into account factors such as road design, environment, and traffic flow. The establishment of speed limits reflects a balance between maintaining road safety and reducing traffic accidents, while allowing vehicles to travel at a reasonable speed for efficient road use. Driving at excessive speeds increases the risk of traffic accidents, leading to more severe injuries or fatalities.