Transport Planning and Design Manual Vol 4
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Time
Phase A
Phase B
Early cut-off
Phase C
Phase E
Early early-off
CASE 1
Saturation flow
Volume
Flow ratio (y)
Critical y
NB
NB/RT
SB
1900
1200
2080
500
100
200
Traffic Flow Theory:
Shockwave
Hong K LO
Civil Engineering
HKUST
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Shockwave Analysis
A shock wave is said to exist whenever traffic
streams of varying stream conditions meet.
Flow-speed-density states change over space and
time. When these changes oc
Optimization Approach
In the idealized situation where traffic arrives uniformly and deterministically to a
signalized intersection, one can model the traffic control system as a D/D/1 queuing
regime. The timing plan to minimize the total delay per cycle
CIVL 563 Traffic Control Fundamentals
Homework 2
Due Date: April 21, 2010
1.
The timing plan of an approach (with 1-lane) to an intersection is as follows:
Effective red: 30 seconds
Effective green: 30 seconds
The approach volume is 600 vph and the discha
CIVL 563 Traffic Control Fundamentals
Homework 1
Due Date: March 17, 2010
ANSWER ALL FIVE QUESTIONS
1. An intersection approach has three lanes, permitted right turns, 8% right turns
with a through vehicle equivalent of 4.50, and a saturation flow rate of
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Dynamic Intersection Signal Control
Optimization (DISCO)
Hong K LO
Civil Engineering
Hong Kong University of Science and Technology
Traffic Control Basics
Traffic Flow
: Queue
Traffic Flow
Traffic Flow
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Traffic Control Basics
Traffic Flow
: Queue
Traff
Continuum Kinematics Model (I)
Hong K LO
Civil Engineering
HKUST
1
Conservation
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k q
+
=0
t x
In general, we assume that the relationship between flow
and density varies only with x, but not t. Sometimes, people
refer this as the stationary or equilibr
Traffic Flow Theory:
Microscopic Car following Models
Hong K LO
Civil Engineering
HKUST
1
Microscopic Density Characteristics
Concerns with the longitudinal space occupied by
individual vehicles in the traffic stream
Relates to safety, capacity, and lev
Basic Principles of Intersection
Signalization
Hong K LO
Civil Engineering
HKUST
1
Types of Intersections
Intersection at
grade
Grade separation
without ramps
Interchanges: rely
on geometry to
avoid conflicts, for
high volumes and
safety; high cost
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