A linear model for determining coordination of two adjacent signalized intersections
Purpose – Urban networks are usually divided into several open or closed sub‐networks. Signal coordination has been recognized as one of the most efficient methods of controlling sub‐networks that have independently optimized timing plans. However, coordinating adjacent intersections in a network is a basic prerequisite to optimizing signal‐timing plans for sub‐networks. This paper aims to develop a linear model to support decisions regarding coordination of adjacent signals.Design/methodology/approach – This paper aims to develop a linear model to support decisions regarding coordination of adjacent signals. The tests of this model which using the field data differ from those for calibration from various roadways, indicating that the model has transferability. Evaluations using microscopic simulation show that the model can objectively determine whether or not to interconnect adjacent signals depending on various traffic demands.Findings – The model was calibrated by stepwise regression analysis with a t...
VEHICLE PLATOON PARAMETERS: METHODOLOGY FOR TRAFFIC CONTROL (ABRIDGMENT)
This paper discusses traffic flow characteristics in the Baltimore Harbor Tunnel and evaluates traffic control alternatives. The method used to evaluate the control alternative was to inspect the average platoon velocities (APV) of each control alternative. Several conclusions were reached as to the evaluation of traffic control alternatives. The platoon parameters provide and simple and effective methodology for the evaluation of control alternatives. The parameters APV established that the no-control, 120-s, 160-s, and 180-s cycle length alternatives yielded high and almost constant velocities through the tunnel. Lastly, the platoon flow values established that in some platoon concentrations (PC) and velocity ranges one alternative predominated. A control policy utilizing the no-control, the 120-s, and the 160-s alternatives was proposed.
CONCURRENT USE OF MAXBAND AND TRANSYT SIGNAL TIMING PROGRAMS FOR ARTERIAL SIGNAL OPTIMIZATION
Number of computer programs have been developed for the purpose of optimizing signal timing. All of the current programs, however, have some deficiencies. The TRANSYT program, which is the most widely used, has a good triffic model and optimizes green phase time. However, it does not get a globally optimal solution, optimize phase sequence, or really optimize cycle length. The MAXBAND program, which optimizes arterial bandwidth, does all of the above but is deficient in that green time is not optimized and the traffic model used is oversimplified. It is shown that a feasible way to overcome these deficiencies is to use the MAXBAND program to develop an initial timing plan for TRANSYT. This initial timing plan includes both cycle length and phase sequence optimization. The timing plans produced by the TRANSYT and MAXBAND programs separately were compared with the combined timing plans by using the NETSIM model. The results indicate that a substantial improvement in measures of effectiveness is obtained with the combined timing plans.