What weight must vehicles stop at any official weighing station?

In Illinois, vehicles that weigh 16,001 pounds or more are required to stop at official weighing stations. This regulation is crucial for maintaining road safety and preventing excessive wear on infrastructure. When a vehicle exceeds this weight limit, it may require special permits or be subject to additional regulations and inspections to ensure compliance with safety standards. Stopping at these stations allows authorities to monitor vehicle weights and ensure that they are within legal limits, which helps prevent damage to roads and bridges that can occur due to overweight vehicles. Therefore, the requirement applies to vehicles weighing 16,000 pounds or more, making the given answer correct.