SIMULATION OF A SIGNALIZED INTERSECTION:

A signalized intersection offers a wealth of data. From vehicle counts, speeds and occupancies to driver and passenger characteristics, the possibilities are almost endless. A simulation and statistical analysis can illustrate and simplify this seemingly complex process.
While a variety of intersection data exists, at this site, you can observe assembly and evaluation of two key sets of intersection data for each of the twelve movements: interarrival times between vehicles and counts of vehicles per cycle. A movement describes vehicle approach direction (northbound, southbound, westbound, and eastbound) and final maneuver (through, right turn, and left turn). A cycle is the series of green (and red) phases that completes one full use of the intersection (so that every movement is served, exactly once in most signal timing plans).
The simulations are based on data acquired at the intersection of Red River Road and Dean Keeton Street just west of IH 35 on the northeast corner of the University of Texas at Austin campus. Very little data acquisition is required for this sort of simulation. Necessary inputs are:
The estimates of arrival times came from a period of just two hours: one during a weekday morning (“rush hour” or “peak period”), the other during a weekday lunch hour (“offpeak period”). The total cycle lengths at those two times of day are 100 and 140 seconds, respectively.
Instructional Objectives:
By reviewing the simulation, you will be able to do the following:
Key Concepts & Questions:
After you have looked at the simulation, try to answer the following questions.
Key Quantitative Questions:
After downloading the appropriate data set(s), answer the following questions.
Development:
This site was envisioned by Dr. Kara Kockelman, Associate Professor of Civil Engineering, at the University of Texas at Austin, and coded in Flash software by the College of Engineering’s Faculty Innovation Center’s Matt Mangum and Amar Mabbu, with assistance from Dr. Kathy Schmidt. Graduate students Chris Frazier and Qi Wang contributed all data. Special thanks to David Castillo at www.flashsim.com.
Copyright ©2004 Kara Kockelman & The University of Texas at Austin Created by The Faculty Innovation Center 