First Experiment: Compute Basic Performance Measures

The purpose of this first experiment is to run the computer program LEAM and compute the basic performance measures of flow rate (throughput) q, mean travel time, T, and the average number of vehicles, the traffic volume V along the highway segment of length L miles and fixed number of lanes N and an input flow rate . The program requires you to input the maximum vehicle speed in mph and the maximum jam density.

Linear Exponential

L miles

N lanes

input flow rate vph

Maximum vehicle speed (mph)

Maximum jam density

Record the outputs: q, T, V, pc, ρ.

The blocking probability Pc is an extra output measure which quantitatively measures
the congestion on the highway segment. This probability ranges from
a low of 0 to a high of 1. A low value of 0 indicates very little blocking along the highway segment, while a value close to 1 represents significant congestion and basically the roadway traffic coming to a halt. Another performance measure output is
ρ which measures the percentage utilization of the capacity of the highway segment.


Animation of Highway segment

Experiment 1: Please run the LEAM model for a sample highway segment. Now take your first experiment and record what happens when input flow rate \Lambda is increased in increments of say 1000 vph? Please graph the effects on a separate piece of paper.

  • Please do this for both the linear and exponential models.
    Why do you think the results are different for the linear and exponential models?
  • What other types of experimental variations might you try?
  • Please suggest one and compare the linear and exponential models with your suggestion.