Method for calculating carrying capacity of urban road network

Abstract

The invention discloses a method for calculating the carrying capacity of an urban road network. The method comprises the following steps that: correlated data of a sample vehicle are collected; a relational expression between a road network load and a road network uniform speed is fitted based on the data of the sample vehicle, and a lowest operation speed of the road network is obtained based onthe relational expression; maximum likelihood estimation is carried out on vehicle speed probability distribution parameters mu and sigma<2>, wherein the vehicle speed probability distribution complies with lognormal distribution In(mu, sigma<2>); curves of changing of the vehicle speed sample probability distribution parameters mu and sigma<2> with the uniform road network speed are established,a dynamic model of road network vehicle speed probability distribution with the uniform road network speed is established, calculation is carried out to obtain speed changing coefficients a, b, c, and d, a vector u being equal to [a, b, c, d] is defined as a road network vehicle speed distribution dynamic feature vector, wherein mu^ is equal to a log (v^+b) and mu^<2> is equal to ce<dv^>; and thelowest operation speed of the road network as a uniform road network speed is introduced into a dynamic model of the corresponding-level road network to obtain a vehicle speed distribution parameterunder the uniform speed, and matching with a corresponding-level road speed-density relation curve and calculation are carried out to obtain the carrying capacity of the road network at the level. Therefore, the efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of traffic condition analysis, in particular to a method for calculating the carrying capacity of urban road networks. Background technique [0002] Urban traffic is the result of the comprehensive effect of many contradictions, among which traffic demand and traffic carrying capacity are a pair of main contradictions and the fundamentals of urban traffic. Traffic carrying capacity refers to the maximum transportation service capacity that the urban transportation system can provide, and it is a restrictive condition for urban development. According to different travel modes, urban traffic is divided into multiple subsystems such as urban road network, ground bus, rail and bicycle, each with its own corresponding carrying capacity. Among them, the urban road network is the most closely related to the public, the most extensive, and the most influential transportation subsystem. The carrying capacity of the ...

AI Technical Summary

Problems solved by technology

Its technical features include: 1. The road network capacity is obtained by calculating the road section capacity and then integrated; 2. It is obtained based on theoretical derivation based on road design parameters; 3. The static capacity is given without considering the interaction between road sections during the road network operation Impact on road network capacity

As a result, there is a large gap between the calculated road network capacity and the actual one, and the calculation amount is complicated

Images