SPEED REDUCTION EFFECTS OF URBAN ROUNDABOUTS

Road safety is one of the most serious problems in road traffic in many countries, including the Baltic countries. One of the alarming issues in road safety is the safety on urban crossings. As the number of intersections is still in a very bad and unsafe shape, there is a big need to reconstruct these intersections in a modern way. Roundabouts are coming more and more popular in many countries of he world, and often they are considered to be as one of the basic intersection types in urban areas. In Estonia, as in most European Countries, roundabouts have steadily become more and more popular during the last years especially because of the foreign experience - showing the excellent accident records, traffic performance, and traffic calming properties. But still some doubts have been encountered in Estonia regarding potential capacity restrictions, traffic restrictions for big trucks and buses and sometimes with traffic safety treatments for bicyclists, pedestrians and the disabled. No overall statistics regarding the present number, growth rate, and design of roundabouts in Estonia are available. The goal of this paper was to find which factors could affect the drivers' speed choice at roundabouts. By the of obtained data we can follow up, that the main factor influencing the drivers' speed choice is an inscribed circle diameter of the roundabout.