Abstract: In order to describe the time headway distribution characteristics of different control types at roundabouts, an investigation was carried out in different sections and different lanes at roundabouts both with and without signal heads in Changchun. Several distribution models were used to analyze the headway distribution in both weaving and circulating areas, such as Weibull distribution, shifted lognormal distribution, double shifted negative exponential distribution and JohnsonSB distribution. The maximum likelihood estimation method and Levenberg-Marquardt method were used to estimate the parameters in the distribution models, and a single-sample Kolmogorov-Smirnov test was used to examine the goodness of fit to the distribution models. Finally, the relationships of lanes between different controlling types and different lanes in the same roundabout were measured by two-sample Kolmogorov-Smirnov test. The results show that there are significant differences in headway distribution among different types of roundabouts, and certain differences in different regions under the same type of control; and JohnsonSB distribution and shifted lognormal distributions have better goodness of fit among the distribution models.

Key words: engineering of communication and transportation system, time headway, distribution model, kolmogorov-smirnov test, roundabout