In order to study the possible positive effects of changing a traffic signal intersection to a roundabout, a survey was performed during autumn 1989 and spring 1990. The intersection has a central downtown location in the city of Joenkoeping, Sweden. The survey was done as a before- after- study and is primarily concentrating on differences in the vehicle time consumption when driving through the intersection. The survey is an integrated part and a case study within a larger research project aiming to create a Method and Model for Comparative Intersection Research. The research methodology is based on the use of video pictures taken from the air (helicopter) or from a high located observation point. A special computer program has been developed for facilitating the data evaluation process, giving a descriptive presentation of relevant traffic flow parameters. The study gave very positive performance results for the roundabout compared to the traffic signal intersection, and the time saving was remarkable.
Abstract