Flyover
Flyover a flyover or overpass is a bridge that carries an elevated roadway or railway line over another roadway or railway line, including or excluding supplementary roads to communicate between the two. When two roads cross on the same level, both are closed and opened in turns by signal, and the traffic movement at the crossing point becomes half. This system causes delays and traffic congestion when the traffic on the roads increases. To avoid this situation in busy crossing, one road is elevated by constructing a bridge to allow free traffic movement on both the roads. The elevated road is called flyover. Again, when a road having no scope for lateral expansion becomes overloaded with traffic, another high-level road over the existing road is constructed to reduce the traffic load of the ground-level road. The high-level road is called a flyover, usually used by fast-moving traffic. Flyovers are also constructed on expressways and national highways to cross local roads and other obstructions.
Construction of flyovers in the cities improves traffic flow and reduces traffic congestion, but they have adverse effects on users of the ground and first floors of the buildings on both sides of the flyovers. They are deprived of light and openness due to obstruction of the flyovers. Flyovers take the sound and vehicular emissions and particulates to higher levels that cause wider dispersion of pollutants in the surrounding environment. Flyovers, not having adequate space for ascending and descending ramps or that occupy enough space for ground level roads, become the cause of traffic congestion in many cities and towns.
Many flyovers have already been constructed in Dhaka and Chittagong cities to ease traffic congestion; Mayor Mohammed Hanif flyover constructed in Dhaka is the longest among them. Other important flyovers in Dhaka are the Mirpur-Airport flyover, Magbazar-Mouchak flyover, Kuril Flyover, Mohakhali flyover, Banani flyover, Tejgoan link flyover, and Khilgoan flyover. The most impressive flyover in Bangladesh is located at Bhanga, Faridpur, at the crossing of Dhaka-Khulna National Highway (N8-N805) and Faridpur-Barisal Highway (N8-N804). [M. Feroze Ahmed]
