What is the maximum speed limit for trucks under 5 tons and passenger vehicles, including motorcycles with engines over 125cc?

The correct answer to the question about the maximum speed limit for trucks under 5 tons and passenger vehicles, including motorcycles with engines over 125cc, is indeed 80 km/h.

In Japan, the general speed limit for these types of vehicles on conventional roads is typically set at 80 km/h unless otherwise specified. This limit reflects considerations for safety, traffic regulation, and road conditions, balancing the need for efficient transportation with the safety of all road users.

The laws governing speed limits take into account the performance and handling capabilities of these vehicles, ensuring that operations remain safe while allowing for reasonable travel speeds. Furthermore, this standard aligns with practices in many areas worldwide, where consistent limits help in maintaining order and predictability on the roads. The speed limit for different vehicle categories, including those mentioned in the question, is designed to facilitate smooth traffic flow while minimizing risks associated with higher speeds.