What is the primary objective of having grade separated intersections in expressway design?

The primary objective of having grade-separated intersections in expressway design is to accommodate extremely high flows of traffic. This design allows vehicles to travel at high speeds without the interruptions that are common at at-grade intersections, where vehicles must stop or yield due to cross traffic. By separating the grades, usually through overpasses or underpasses, vehicles can continue moving efficiently, reducing delays and enhancing overall traffic flow.

This configuration is particularly important for expressways, where maintaining a consistent speed and minimizing disruptions is crucial for safety and performance. Grade separation eliminates the need for stop signs, traffic signals, or other traffic control devices that can impede the movement of high volumes of vehicles. This uninterrupted flow is vital for managing the demands of heavy traffic, especially during peak usage periods on expressways that cater to long-distance travel.

Other factors, such as property access, jointing needs, or aesthetics, are not the primary focus of grade-separated designs, which are centered around maximizing traffic capacity and safety on high-speed roads.