On expressways, traffic intersections are replaced by?

• A. Stop signs
• B. Crosswalks
• C. Roundabouts
• D. Interchanges

Answer: (D)

The key idea is that expressways are built for high-speed, uninterrupted traffic, so traditional at-grade intersections aren’t used. Instead, a design that separates the levels of traffic and provides controlled entry and exit is used: interchanges. Interchanges use overpasses or underpasses with ramps that let vehicles enter, exit, or cross the expressway without stopping for opposing traffic or navigating a crossing at the same level. This keeps the main roadway moving smoothly and safely, reducing conflict points and bottlenecks.

Stop signs would force vehicles to stop on a fast, high-speed road, creating dangerous situations and severe congestion. Crosswalks at expressway speeds are unsafe because pedestrians and vehicles would be interacting at speeds that leave little time to react. Roundabouts require at-grade traffic flow and slower speeds, which don’t work for expressways designed for continuous movement. Interchanges, by separating traffic levels and providing ramps for entering and leaving, are the appropriate solution.