טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentHamzy Mendy
SubjectMicroscopic Analysis of Dense Flow on Freeways
DepartmentDepartment of Civil and Environmental Engineering
Supervisors Professor Abishai Polus
Mr. Moshe Pollatschek (Deceased)


Abstract

The present work develops a simulation with the aid of the Excel computer program in an attempt to examine how the interruption of speed affects the flow and how it can bring about its deterioration. This simulation is based on an examination of the behavior of a column of 8 vehicles when a speed-interfering element is introduced that fragments normally (0, 1). The simulation shows that a small interruption does not affect the column, which still travels homogenously and at uniform speed, without strong and significant fluctuations. With an increase in the interruption, signs can be seen of the vehicles crowding one another, accompanied by a decrease in speed.


Numerical data was collected from the Netivei Ayalon Co. of a segment of the KKL Road south: volume, speed every 5 minutes throughout the day for five days. The following parameters were calculated from these data: flow, volume, and peak time around 7:30 a.m., with a volume of  6,800 private vehicles/hour/3 lanes.  All the calculations were carried out; the equivalency coefficient of trucks and buses was 1.5 (private vehicle).


In addition, the PHF and the percentage of trucks values were calculated and Design parameters were computed, such as the heavy-vehicle-correction coefficient, the rate of flow per lane, and the free-flow speed.  An estimate was made of capacity and speed on this segment by correlating two models, one in the free-flow region, to which a parabolic model was correlated; and the second in the region of the constrained flow, to which an exponential model was correlated.  Results were obtained of a capacity of around 1,800-2,100 private vehicles/hour/3 lanes, with speeds of between 65 and 85 km/hr.


For the purpose of computing free-flow speed on this segment, only the speeds were used, with the volume being up to 1,500 private vehicles/hour/3 lanes.  A result was obtained of 105 km/hr, compared to 103 km/hr from the calculation according to the HCM equations.