CE93  Engineering Data Analysis
Prof. Joan Walker, Spring 2011
1
Lab 12
(April 20, 2011)
Based on the relationship between flow and density of the vehicles, traffic states within a
freeway section can be classified either as
(i) Free flow or
(ii) Congested flow
where flow is defined as the number of vehicles (n) which pass at a fixed location during a
certain time interval (T), (i.e. n/T). Density is defined as the number of vehicles (m) which exist
over a certain freeway section of length (L) at a fixed time, (i.e. (m/L)).
Flow will increase with the density when vehicles are freely flowing in the freeway section. On
the contrary, flow will decrease with density once the freeway section becomes congested (i.e.
queued with vehicles), in which case more cars will make a traffic jam worse. Now we are going
to examine the flowdensity relationship using traffic data measured by inductive loop
detectors that are located at D1 as shown in Figure 1. The detectors there provide aggregated
vehicle counts and average occupancies (dimensionless measure of density).
N
0
.9
m
i
.
3
D1
Inductive
Loop Detector
Detector
Station
Figure 1. Freeway site, at I5 N, Sacramento, California
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentCE93  Engineering Data Analysis
Prof. Joan Walker, Spring 2011
2
Download
“
data.txt
”
in the bSpace (> Resources > Labs > Lab12).The first column of
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Staff
 Linear Regression, Regression Analysis, Engineering Data Analysis, Prof. Joan Walker

Click to edit the document details