Write advantages and disadvantages of rotary intersection.

Advantages of rotary intersection

• They are best suited to moderate traffic, particularly with irregular geometry, or intersections with more than three or four approaches.
• All turns can be made with ease.
• Frequent stopping and starting are avoided.
• All traffic proceeds simuntaneously and continuously at uniform speed.
• For moderate traffic, rotaries are self-governing and need no control by police or traffic signals.
• Both vehicles approaching the rotary compartment are softly pressured to slow down and keep going at a slower pace. As a consequence, none of the cars need to be stopped, unlike a signaled intersection.
• Orderly and disciplined traffic flow is provided by the one-way movement.
• The capacity of rotary intersection is the highest of all other intersections at grade.
• The flow of traffic is controlled in only one direction of travel, thereby avoid significant disputes between crossing movements.
• Direct conflict is eliminated.
• It reduces crossing conflicts from 16 to 4.
• A rotary is especially suited for intersection legs ranging from 4 to 7.
• Because of the slower pace of negotiation and the avoidance of major disputes, injuries and their seriousness are much less likely to occur in rotaries.
• Frequent stopping and starting of vehicles are avoided.
• Rotaries are self-administering as well as fundamentally don’t need any oversight from police or traffic lights.

Disadvantages of rotary intersection

• At the places of mixed traffic, the design of rotary becomes too elaborate and the operation and control of traffic become complex.
• Traffic turning right has to travel a little extra distance.
• It is not suitable where angle of intersection between two roads is too acute.
• Where the traffic volume is very low, construction of a rotary cannot be justified.
• It requires many warning and directional signs for safety.
• Rotaries need an extensive area of comparatively flat land, making them expensive for urban areas.
• Rotary requires comparatively large of land. So where space is limited and costly, the total cost may be high.  
• Where the angle of intersection of two roads is too acute or when there are more than seven intersecting roads, rotaries are unsuitable.  
• Both cars required to slow down and negotiate the junction. As a result, the average delay would be greater the channeled intersection.
• Typically, the cars do not stop at the rotary. They accelerate and leave the rotary mechanism at a reasonably high speed. They are not acceptable when there are high movements of the pedestrians.
• And when traffic is moderately light, cars are required to reduce their speed.
• At the places of mixed traffic, there is a tendency to violate the traffic regulation of clockwise movement.  
• When the distance between the intersections on important highways is less, a rotary becomes troublesome.   
• Where the pedestrian traffic is large, the rotary by itself cannot control the traffic and needs control by traffic police. If the vehicular traffic has to stop to allow the pedestrian to cross, the main purpose of rotary has defected.