In roadway design, what do vertical clearance calculations help ascertain?

• A. Roadway capacity
• B. Construction materials
• C. Safe passage under structures
• D. Cost estimates

Answer: (C)

Vertical clearance calculations are essential in roadway design as they determine the height available for vehicles to safely pass beneath structures such as bridges, overpasses, and overhead signs. This measurement ensures that the roadway is accommodating to vehicles of varying heights, including trucks and buses, which may require more clearance than standard passenger vehicles.

Ensuring proper vertical clearance helps prevent accidents and damage to vehicles that could occur if a vehicle misjudges the height requirement and tries to pass underneath a structure that is too low. It also facilitates compliance with transportation regulations, ensuring that the design will meet safety standards for both normal traffic flow and in emergency situations.

While other aspects like roadway capacity, construction materials, and cost estimates are important in overall roadway design, they do not directly address the critical safety concern that vertical clearance calculations specifically focus on.