Steps of traffic organization and optimization program design include traffic survey and data analysis, traffic modeling, simulation modeling, program design and evaluation.
Collect static and dynamic information of the main roads and nodes in the region (including geometric parameters of the road network, channelized layout, number of lanes, etc.), traffic flow and direction by vehicle type, signal timing at intersection, speed, occupancy, queue length, vehicle characteristics, driving behavior characteristics, etc.
Data processing and analysis of traffic problems
Obtain the measured traffic flow through field survey, collate the raw data and determine the traffic occurrence and attraction volume among all traffic areas with Furness model, analyze saturation degree, queuing status and cause of traffic congestion at intersections according to traffic conditions there and evaluate the existing traffic organization program.
Traffic simulation modeling
Perform modeling with TRANSYT traffic modeling software and VISSIM traffic simulation tool, as shown in the figure below.
Road Network Status Model in TRANSYT
Road Network Status Model in VISSIM
Model calibration and validation
Validate the simulation model with traffic characteristic parameters collected in the actual survey so as to make the simulation results match with the actual traffic conditions.
Signal control design
On the basis of the calibration model, optimize signals of the intersection with TRANSYT and verify and evaluate the optimization program combining with VISSIM, so as to get the optimum signal timing, as shown in the figure below.
Intersection Signal Timing Optimization
Evaluation of the optimization program
Select delay, stops, queue length at intersection, travel time, average speed on the road section and other indicators as those for comprehensive evaluation, perform statistics of and comparative analysis on the various optimization programs and propose the corresponding suggestions for optimization.
Cities of application
Keli has a “traffic signal organization and optimization team” comprising a dozen of experts and professionals that have been engaged in signal control for many years to provide the world's leading TRANSYT, VISSIM and signal control optimization, two-way green wave design, transport advisory services and other services. So far, we have provided high-quality regional organization and optimization services and traffic simulation aid decision making services in Hefei, Xuancheng (Anhui Province), Fenghua (Zhejiang Province), Zhongmou (Henan Province), Wuhan (Hubei Province) and other cities to improve their traffic capacity and efficiency, and therefore, have been highly recognized by the clients.