Speed-measuring and statistical research of vehicles on two intercity highways in Jiaxing
Taking two sections of highway within the borders of Jiaxing from G15w Changzhou-Taizhou Highway and G60 Shanghai-Kunming Highway respectively as subjects, this article researches into the traffic flow on double-lane and multi-lane by field shooting, speed data collecting and statistical analysis. It is discovered that the traffic flow of intercity highway with higher proportion of freight vehicle is different from that of urban expressway. There is obvious difference between the velocity distribution of passenger car and freight vehicle, and the general vehicle velocity distribution reveals the feature of double peak. Based on these discoveries, it is proposed in this article that a five-parameter probability density function which can depict the double peak feature of vehicle velocity distribution. All the parameters have clear physical meaning and can be adjusted according to different position, height and variance of peak value in concrete problems. According to the result of fitting and optimizing three measured samples, distance between two peak values of multi-lane section is larger than that of double-lane section, while the concentrative degree of speed data(especially speed of freight vehicle) in weekend is higher than that of working day.