What is the Difference Between Flyover and Underpass?

The main difference between a flyover and an underpass lies in their design and construction. Both structures are intended to facilitate the movement of traffic and pedestrians at busy intersections, but they serve different purposes and have distinct characteristics.

Flyover:

A flyover is an overpass constructed over a main road, allowing traffic to pass over a busy intersection without stopping.
It is built at a higher level than the main road, providing unobstructed flow of traffic.
Flyovers are often costly to construct and take more time to be built.
They can be used for both vehicles and pedestrians, sometimes resembling an underground tunnel built in the air.
In North American usage, a flyover is a high-level overpass, built above main overpass lanes.

Underpass:

An underpass is a passage built underneath a road or railway, allowing traffic to move downward and pass under a busy road.
It provides a lower-level alternative for traffic to avoid congestion at the surface level.
Underpasses are generally easier and less costly to construct compared to flyovers.
They can be used for both vehicles and pedestrians, sometimes connecting parts of a developed area or providing access to amenities.

In summary, flyovers are roads above roads, while underpasses are passages built beneath other roads. Both structures serve to improve traffic flow and accessibility, but their design and construction differ significantly to accommodate different traffic patterns and infrastructural needs.