In Japan, the basic highway bridge design code applies to bridges with span shorter than what length?

• A. Less than 100 meters
• B. Less than 200 meters
• C. Less than 150 meters
• D. Less than 250 meters

Answer: (B)

In Japan, the basic highway bridge design code is written for the majority of typical highway bridges where the span isn’t very long. The scope is spans shorter than 200 meters. This limit exists because, for shorter spans, standard loads, typical materials, and conventional structural behavior can be captured with a common, straightforward set of design rules. When spans reach or exceed 200 meters, however, dynamic effects become more influential—wind-induced vibrations, aeroelastic interactions, and seismic demands over a longer deck—so more specialized long-span design provisions are needed. That’s why longer spans call for different, long-span or advanced design standards, while shorter spans fall under the basic code.