Lecture 7 - Special Issues
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Transcript Lecture 7 - Special Issues
Topic 7
Special Issues on Signal
Coordination
CEE 764 – Fall 2010
Signal Timing with Large Systems
Difficult to obtain high bandwidth efficiency with
a large number of signals in a system.
Only a small portion of the traffic goes through
the entire arterial.
Seeking a system progression band with low
efficiency may not be a good signal timing
strategy.
CEE 764 – Fall 2010
System Partition Technique
Step 1. Divide the system into sub-systems
(3~5 signals)
Divide at locations of capacity bottleneck and large spacing
Step 2. Obtain maximum bandwidth solution for
each subsystem
Step 3. Form the peak direction progression
band
Adjust offsets to achieve an one-direction bandwidth (peak)
Subsystem progression is retained for the other direction
Step 4. Fine tune the solution
Possible signal phasing change to improve the off-peak
direction progression band;
Cross street with split phasing should be set at a sequence
favoring progression of the left turns.
CEE 764 – Fall 2010
EXAMPLE
CEE 764 – Fall 2010
10. University Dr.
Offset: 0 (Master)
9. Lone Star
Offset: 34
EXAMPLE
8. Walton Rd.
Offset: 44
7. George Bush Dr.
Offset: 102
6. Harvey Rd.
Offset: 53
5. Holleman Dr.
Offset: 33
4. Brentwood Rd.
Offset: 1
3. Southwest
Parkway
Offset: 29
2. FM 2818
Offset: 89
1. Deacon Dr.
Offset: 42
CEE 764 – Fall 2010
Arterial Band
Partial Band
10. University Dr.
Offset: 0 (Master)
? 1 = 32 Om = 120
9. Lone Star
Offset: 28
tm = 88
EXAMPLE
8. Walton Rd.
Offset: 47
7. George Bush Dr.
Offset: 105
to1
t e2 = 5
= 49
39
O7 = 105
t’e2 = 86
6. Harvey Rd.
Offset: 38
5. Holleman Dr.
Offset: 32
4. Brentwood Rd.
Offset: 100
3. Southwood
Parkway
Offset: 112
2. FM 2818
Offset: 53
CEE 764 – Fall 2010
1. Deacon Dr.
Offset: 105
te2 = 125
10. University Dr.
Offset: 0 (Master)
9. Lone Star
Offset: 28
EXAMPLE
8. Walton Rd.
Offset: 47
7. George Bush Dr.
Offset: 24
6. Harvey Rd.
Offset: 77
5. Holleman Dr.
Offset: 71
4. Brentwood Rd.
Offset: 16
3. Southwest
Parkway
Offset: 28
2. FM 2818
Offset: 89
1. Deacon Dr.
Offset: 21
CEE 764 – Fall 2010
NB Band
SB Band
10. University Dr.
Offset: 0 (Master)
9. Lone Star
Offset: 101
EXAMPLE
8. Walton Rd.
Offset: 2
7. George Bush Dr.
Offset: 64
6. Harvey Rd.
Offset: 117
5. Holleman Dr.
Offset: 118
4. Brentwood Rd.
Offset: 47
3. Southwest
Parkway
Offset: 58
2. FM 2818
Offset: 119
1. Deacon Dr.
Offset: 59
CEE 764 – Fall 2010
Arterial Band
Partial Band
Speed Comparison – Arterial All Vehicles
50.0
Tra ve l S pe e d, km /hr
45.9
45.0
43.6
44.4
44.4
44.9
43.6
43.4
42.5
41.4
40.0
35.0
30.0
Northbound
CEE 764 – Fall 2010
S outhbound
P A S S E R II
P ro1
S y s tem
P ro2
Speed Comparison –Through Vehicles
60.0
55.7
Tra ve l S pe e d, km /hr
55.0
54.5
53.3
50.1
50.0
48.9
48.9
47.7
47.3
45.8
45.0
40.0
35.0
30.0
Northbound
CEE 764 – Fall 2010
S outhbound
P AS S E R II
P ro1
S ystem
P ro2
Advantages
Maintain maximum progression for the peak
direction.
Maintain maximum progression for the
subsystems.
The one directional progression band for the peak direction is the
maximum that can be achieved from any optimization solutions.
Subsystems have larger bandwidths on both directions.
More control and handle on queue and stops
Progression on the off-peak direction is partially maintained. But the
users have complete control on where to stop vehicles and store
queues.
CEE 764 – Fall 2010
Pedestrian Timing Treatment
Pedestrian crossing times are handled by
concurrent vehicle through phases
Green time of vehicle phase must satisfy the
WALK + FDW
Vehicle demands are low at minor streets, but
pedestrian crossing times are high (wide street)
Split phasing presents more challenges
Two timing treatments
Vehicle minimum
Pedestrian minimum
CEE 764 – Fall 2010
Pedestrian Timing Treatment
Left Turn
Leading
Lead/Lag
Time
CEE 764 – Fall 2010
Pedestrian with Split Phasing
CEE 764 – Fall 2010
Advantages/Disadvantages
Vehicle Minimum
Optimal Cycle Length
Signal Out-of-Coordination
Timing Plan Reflects Actual
Progression
Easy Timing Plan
Development
CEE 764 – Fall 2010
Pedestrian Minimum
Cycle Length Constraint
Remain Coordination
Progression According to
Early Release
Major Manual Adjustments
IDENTIFY EARLY RELEASE POINT
NODE
123456789012345678901234567890123456789012345678901234567890123456789012345678
1
2
XXXXXXX
XXXXXXX
3
XXXXX
4
//////////\\\\\\
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///////////\\\\\\
///////////\\\\\\
1947 ft
5
///XXXXXXXXX\\\\
//XXXXXXXXX\\\\
I //XXXXXXXXX\\\\
//XXXXXXXXX\\\\
2647 ft
XXXXXXXX
3376 ft
6
XXX
9
XXX
10
XXXXXXX
11
XXX///
CEE 764 – Fall 2010
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
XXXXXXXX
XXXXXX
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
0 ft
215 ft
XXXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXXX
XXXXXXXX
XXXXXXXX
8
XXXXXXXX
XXXXXXXX
XXXXXXXXX
XXXXXXXX
7
NODE
XXXXXXXX
XXXXXXXX
DISTANCE
947 ft
XXXXXXXX
XXXXXXX
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
4037 ft
XXX
5190 ft
XXXX
5742 ft
XX
7010 ft
\\\\\XXXXX
8380 ft
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1
2
3
4
5
6
7
DISTANCE
EFFECTIVE USE OF PHASING SCHEME
Movement
Southbound Left Turn
Southbound Through
Northbound Left Turn
Northbound Through
Pedestrian Crossing
Average Demand, sec
10
15
20
20
35
10
20
35
35
25
35
35
35
35
Ped = 35
10
Total = 55
(A)
CEE 764 – Fall 2010
Total = 45
(B)
35
USE OF MAXIMUM RECALL
NODE
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1
2
XXXXXXX
XXXXXXX
3
XXXXX
4
//////////\\\\\\
///////////\\\\\\
///////////\\\\\\
///////////\\\\\\
1947 ft
5
///XXXXXXXXX\\\\
//XXXXXXXXX\\\\
I //XXXXXXXXX\\\\
//XXXXXXXXX\\\\
2647 ft
XXXXXXXX
3376 ft
6
XXX
9
XXX
10
XXXXXXX
11
XXX///
CEE 764 – Fall 2010
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
XXXXXXXX
XXXXXX
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
0 ft
215 ft
XXXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXXX
XXXXXXXX
XXXXXXXX
8
XXXXXXXX
XXXXXXXX
XXXXXXXXX
XXXXXXXX
7
NODE
XXXXXXXX
XXXXXXXX
DISTANCE
947 ft
XXXXXXXX
XXXXXXX
XXXXXXXX
XXXXXXXX
\\\\\XXXXXXXXX///
4037 ft
XXX
5190 ft
XXXX
5742 ft
XX
7010 ft
\\\\\XXXXX
8380 ft
123456789012345678901234567890123456789012345678901234567890123456789012345678
1
2
3
4
5
6
7
DISTANCE
Grid Network
CEE 764 – Fall 2010
Grid Network
Φ2
Φ2
2
1
Φ4
Φ4
Φ2
Φ2
Φ4
θ12
3
CEE 764 – Fall 2010
Time 0
4
Φ4
Grid Network
Φ2
Φ2
2
1
Φ4
Φ4
Φ2
θ12+Φ2
θ12
Φ2
3
Φ4
CEE 764 – Fall 2010
Φ2
Φ4
Time 0
4
Φ2
Φ4
θ12+Φ2+θ23
Φ4
Grid Network
Φ2
Φ2
2
1
Φ4
Φ4
Φ2
θ12+Φ2
θ12
Φ2
3
Φ4
CEE 764 – Fall 2010
Φ2
Φ4
Time 0
4
Φ2
Φ2
Φ4
Φ4
θ12+Φ2+θ23
θ12+Φ2+θ23+Φ4
Φ4
Φ2
Φ4
θ12+Φ2+θ23+Φ4+θ34
Grid Network
Φ2
Φ2
2
1
Φ4
Φ4
Φ2
Φ2
Φ4
θ12
Φ2
Φ2
Φ4
θ12+Φ2+θ23+Φ4+θ34+Φ2+θ41+Φ4
3
4
Φ2
Φ4
CEE 764 – Fall 2010
Φ2
Φ4
Φ2
Φ4
Φ4
θ12+Φ2+θ23
θ12+Φ2+θ23+Φ4+θ34
θ12+Φ2+θ23+Φ4+θ34+Φ2
Grid Network
θ12+Φ2+θ23+Φ4+θ34+Φ2+θ41+Φ4 = NC
θij = tij = Lij /Sij
Φ2 + Φ4 = C
4θij+2C = NC
4θij = NC
θij = NC/4 = C/4
CEE 764 – Fall 2010
Example
For a grid one-way street network, each block
has 300 ft. Suppose both directions at each
signal have the same phase splits.
(1) What would be the cycle length if the
progression speed is designed to be 20 mph?
(2) If the cycle length is 60 sec, what would be
the fastest progression speed?
CEE 764 – Fall 2010