How often must regular passenger vehicles undergo inspection for private use?

Regular passenger vehicles for private use in Japan must undergo inspection every 12 months. This practice helps ensure that vehicles remain in safe operating condition and meet environmental standards. The annual inspection process, known as "Shaken," involves a thorough examination of the vehicle's safety features, emissions, and overall performance. By mandating these inspections annually, the system aims to enhance road safety as well as reduce pollution by ensuring that vehicles comply with current regulations.

While options suggesting shorter or longer intervals might seem reasonable at first glance, the structure of the vehicle inspection system is designed to strike a balance between ensuring vehicle safety and not imposing excessive burdens on vehicle owners. Therefore, the correct interval for regular passenger vehicles is indeed once a year.