טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentVinitsky Irina
SubjectFlow and Passing-Lanes Characteristics on Two-Lane Highways
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Abishai Polus
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

The purpose of this work is to study the characteristics of traffic patterns and flow on passing lanes on two-lane rural roads. The research evaluated passing lanes from different locations in the world that use them as means to improve traffic flow. The study includes analysis of warrants to construct passing-lanes, methods for determining the location of passing-lanes, lengths of passing lanes and the space between them. A comparison of various configurations of passing-lanes and using different ways of marking and signing is also conducted. In order to analyze traffic characteristics of two-lane roads, data were collected on six two-lane highways, in both directions and within several peak-hours. The data collected included: traffic speed and space between following vehicles. Calculations were made to determine traffic volumes during peak-hours and number of vehicles driving inside a platoon and outside a platoon.

Calculations of additional parameters were made, such as the number of headways within platoons and outside platoons, the number of headways among the platoons, speeds within and outside platoons, speeds of first vehicle of the platoon, speeds of the first fast vehicle that follows the platoon. For all the above parameters, calculations were made to determine the averages, standard deviations and histograms. In addition, this work displays the comparison between two methods of calculating the PTSF parameter and calculating of the parameter of traffic intensity Rho. 

In order to check if there are significant differences between speeds of the first vehicle within the platoon and the first following vehicle within the platoon - χ2 tests were conducted. It was found that within 17 peak-hours out of 29 peak-hours tested, there was significant difference between analysis of the first vehicle speed in the platoon and the first vehicle following the platoon.

The PTSF values calculated using the HCM2000 method were found to be higher than the values calculated by the Polus-Pollatschek model. The difference was about 18% for a volume of 200 vph (one-way) and about 34% for a volume of 1000 vph (one-way). This difference was also noted in previous studies and results from over-estimation of PTSF values by HCM2000.

For purpose of determining if there is a significant difference between platoon speeds and vehicles driving in a free-flow following platoons - t-tests were made. It was found, that within 29 peak-hours tested in eight road segments the difference was statistically significant within the 95% confidence level.