بررسي متغيرهاي كلان جريان ترافيك و رفتار رانندگان در مقاطع پايه بزرگراههاي درونشهري﴿مطالعه موردي: بزرگراه شهيد خرازي اصفهان﴾

چكيده انگليسي :

Analysis of Macroscopic Parameters of Traffic Flow and Driver Behaviors in Basic Urban Multilane Highway Segment case study Kharrazi Multilane Highway in Isfahan Mohammad Tamannaei m tamannaei@yahoo com Date of Submission Februrary 9 2011 Department Collage of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Sayyed Mahdi Abtahi mabtahi@cc iut ac ir Abstract The aim of this study is to assess traffic flow and driver behavior in the basic segments of urban multi lane highways The case study is Shahid Kharrazi Highway which is a part of Isfahan third traffic ring In this study the capacity of multi lane highways for different traffic flow conditions was analyzed using the data collected from the highway The investigated parameters are flow rate space mean speed density and time headway For macroscopic capacity analysis macroscopic speed density models such as linear Greenshields model logarithmic Greenberg model and exponential Anderwood model For microscopic capacity analysis a new methodology for determination of capacity of a basic highway section was developed by using a concept named acceptable time headway which is one of the behavioral characteristics of a driver and is defined as the minimum safe headway according to the driver The capacity values obtained from both macroscopic and microscopic analysis were compared to the corresponding values proposed by Highway Capacity Manual HCM The results show that the actual capacities of the studied highway lanes are higher than those suggested by HCM It shows that the driver behavior characteristics of Isfahanian population differ from those of the population considered by HCM The propensity of a large number of drivers to adopt unsafe headways has caused reduction of the mean value of acceptable headways and has increased the capacity For instance in lane 3 at day time hours about 80 percent of the followers adopt headways less than 2 seconds and 35 percent of them adopt headways less than 1 second The statistics show that more than 70 percent of all the accidents occurred in Shahid Kharrazi highway are rear to front accidents This kind of accident is caused mainly by risky behaviors of drivers tailgating and adopting very short and unmanageable headways Because of the fact that the capacity is influenced by headway distribution we analzed the distribution for different conditions Using chi square tests different statistical models with shifts varyinf from 0 to 0 75 seconds were fitted to headway distributions The procedure was done by MATLAB software The results of modeling concluded from 1632 chi square tests show that the appropriate models for headway distribution are different in the passing and middle lanes under heavy traffic conditions The lognormal model with 0 24 seconds shift was selected as the appropriate model for headway distribution of the passing lane For the middle lane the gamma model with 0 69 seconds shift was selected as the most appropriate model This is because of different behavioral operation of drivers which is affected by specific conditions of each lane Because of the specific pattern of drivers for car following in the passing lane and their propensity to tailgate with high speed at peak hours of traffic flow the capacity of passing lane is higher than one for the middle lane and thus the distributions and statistical criteria are considerably different for the lanes Also the car following behaviors are different even at the same flows in different

تمنايي، محمد

بررسي متغيرهاي كلان جريان ترافيك و رفتار رانندگان در مقاطع پايه بزرگراههاي درونشهري﴿مطالعه موردي: بزرگراه شهيد خرازي اصفهان﴾

ظرفيت , تردد , تحليل كلان , تحليل خرد , توزيع , سرفاصله زماني