Capacity of roundabouts as an element of urban logistics

The principles of functioning of roundabouts in Poland are regulated by the Road Traffic Act, introduced on June 20, 1997, and colloquially known as the “Highway Code”. The act regulates the rules of traffic on public roads and in residential areas, the conditions for admitting vehicles to this traffic, requirements for drivers and other road users, as well as the rules for traffic control. This document does not contain the definition of “roundabout” – the colloquial name for an “intersection with circular traffic”.According to the driving manual, “A roundabout is an intersection of roads with circular traffic, where the movement of vehicles takes place in the opposite direction to the movement of clock hands. A roundabout in every case has an island in its central part, which is excluded from vehicle traffic with the exception (sometimes) of tram traffic”5.
An intersection with circular traffic is a good solution, used mainly in urban areas; it is often used in countries with high traffic safety. Compared to other intersections, roundabouts increase capacity and reduce traffic congestion.
Thanks to this, they streamline traffic. On roundabouts, there are fewer points where accidents and collisions can occur than at other types of intersections. The design of the roundabout forces the entering driver to reduce speed and enables better visibility for road users, which increases safety.
As studies show, there are generally 5 times fewer accidents on roundabouts than at other intersections, and 2 times fewer in cities. Thanks to the use of roundabouts, the number of fatal accidents drops by over 95%. In 2007, there were 460 accidents on roundabouts, while 14,336 accidents occurred at other intersections. Among these accidents, the number of accidents with fatalities amounted to 14 fatalities on roundabouts and 826 at other intersections. (…)

Capacity of roundabouts as an element of urban logistics – PDF file for download