Transcript INTEGRATING SIGNAL AND LANE CONTROL Edward Lieberman, P.E. Jinil Chang, Ph. D. 2006 Annual Meeting Panel 5: Emerging Technologies June 9, 2006

INTEGRATING SIGNAL
AND LANE CONTROL
Edward Lieberman, P.E.
Jinil Chang, Ph. D.
2006 Annual Meeting
Panel 5: Emerging Technologies
June 9, 2006
Basic Principles
There are strong interactions among
geometric configuration and signal timing
plans which influence traffic performance
Treating these elements as an integrated
system can yield optimal, adaptive lane
allocation and signal-timing plans that are
responsive to changing conditions
2006 Annual Meeting - Panel 5: Emerging Technologies
2006 Annual Meeting - Panel 5: Emerging Technologies
2006 Annual Meeting - Panel 5: Emerging Technologies
Intersection Design and Control
Given
1. Estimate traffic volumes, by movement
ROW, Budget constraints
Develop
2. Approach configurations
Rules: < 450 vphl; VL > 100 vph, etc.
Assert/
Compute
3. Signal Cycle Length
4. Signal Phasing Plans
Compute
5. Signal Phase Durations
6. Signal Offsets
A sequential “Waterfall” process
2006 Annual Meeting - Panel 5: Emerging Technologies
Case 1
Case 3a
Case 6b
Possible Lane Assignments

For a given approach width, it is possible to design a
number of different lane-use configurations.

Each can support several [different] signal phases and
durations.
How can we determine the best combination
of approach configurations, signal phasing
plan and signal timing for all time periods?
2006 Annual Meeting - Panel 5: Emerging Technologies
Geometric Configurations of approaches
to signalized intersection
Case 1:
Case 2:
Case 3:
Case 4:
LNT ≥ 1
a) LNT ≥ 2
a) LNT ≥ 2
LNT ≥ 1
b) LNT = 1
b) LNT = 1
Case 5:
Case 6:
Case 7:
Case 8:
a) LNT ≥ 2
a) LNT > 2
a) LNT > 2
a) LNT ≥ 2
b) LNT = 2
b) LNT = 2
b) LNT = 1
c) LNT = 1
c) LNT = 1
Case 9:
Case 10:
Case 11:
Case 12:
a) LNT ≥ 2
a) LNT > 2
a) LNT > 2
a) LNT ≥ 2
b) LNT = 1
b) LNT = 2
b) LNT = 2
b) LNT = 1
c) LNT = 1
c) LNT = 1
Case 13:
Case 14:
Case 15:
Case 16:
a) LNT ≥1
a) LNT ≥ 2
a) LNT ≥ 2
a) LNT ≥ 1
b) LNT = 1
b) LNT = 1
Case 17:
Case 18:
Case 19:
Case 21:
Case 22:
Case 23:
b) LNT = 1
Case 20:
Proposed Intersection Design Procedure
Given, for every time period:
Estimates of traffic volumes
ROW, Budget constraints
Over a selected range of signal cycle lengths…
and for every viable Intersection configuration…
Signal Phasing Plans
Compute
Signal Phase Durations
Signal Offsets
…and select the “best” design/lane allocation and
control plan for each time period
An integrated, exhaustive computational process
2006 Annual Meeting - Panel 5: Emerging Technologies
For each
time period
Enter Inputs
For each
cycle length
N-S Direction
Loop over Configuration
s
Loop over Phase Plans
Select a Feasible
Configuration
Select a
Feasible
Phase Plan
E-W Direction
Select a Feasible
Configuration
Select a
Feasible
Phase Plan
Evaluate
Evaluate
Store Results
Store Results
Perform
Intersection
Evaluation for
all
Phasing/
Configuration
Combinations
Rank and
Present Results
Procedure Flow Diagram
SIG/
Cinema
HCM
Analysis;
Optimal
Phase
durations
Simulation
Animation
ILLUSTRATIVE CONFIGURATIONS
Case 3(a)
Case 11(c)
Case 11(c)
2
Case 3(a)
Configuration 1
3
4
Case 3(a)
1
Case 3(b)
Case 3(b)
Restrict parking on
east-west
approaches.
Case 3(a)
Configuration 2
2006 Annual Meeting - Panel 5: Emerging Technologies
Summary of Results, Configuration 1
Phasing Plan
Arterial
1. Lead/Lag
Permitted
2. Permitted
3. Dual Lead
4. Lead/Lag
Protected
5. Lead/Lag
Permitted
Required Phase
Duration
Arterial
Cross
Total
Sts.
G
L G
L
Cross
Sts.
C = 90 sec.
Slack
CU
Percent Left-Turn Protected
Permitted 32.6 10 29.6
5
77.2
12.8
0.86
Appr.
1&2
44
Permitted 41.0 5 29.6
Permitted 38.8 10 29.6
Permitted 49.8 10 29.6
5
5
5
80.6
83.4
94.4
9.4
6.6
-4.4
0.90
0.93
1.05
0
100
100
0
0
0
0
62.5
62.5
32.6 10 43.6 10
96.2
-6.2
1.07
44
100
65.0
Split
Cycle Utilization, C U 
CS
C
 1
S
C
Appr.
3&4
0
Intersection
27.5
, is a measure of reserve capacity. The lower CU, the greater the reserve
capacity
Reference: Lieberman, E. and Chang, J., Ph.D., New Formulation
to Analyze Signalized Approaches, paper presented at TRB,
January 2006.
www.kldassociates.com
2006 Annual Meeting - Panel 5: Emerging Technologies
Summary of Results, Configuration 2
Phasing Plan
Arterial
1. Lead/Lag
Permitted
2. Permitted
3. Dual Lead
4. Lead/Lag
Permitted
5. Lead/Lag
Protected
6. Dual Lead
7. Lead/Lag
Protected
8 Lead/Lag
Protected
Required Phase
Duration
Arterial
Cross
Sts.
G
L
G
L
Total
Permitted
32.6 10
15.2
5
62.8
27.2
Permitted
Permitted
Dual
Lead
Permitted
41.0 5
38.8 10
32.6 10
15.2 5
15.2 5
21.8 10
66.2
69.0
74.4
49.8 10
15.2
5
Dual
Lead
Split
38.8 10
Dual
Lead
Cross
Sts.
Cycle Utilization, C U 
C = 90 sec.
Slack
CU
Percent Left-Turn Protected
Appr.
3&4
0
Intersection
0.70
Appr.
1&2
44
23.8
21.0
15.6
0.74
0.77
0.83
0
100
100
0
0
100
0
62.5
100
80.0
10.0
0.89
100
0
62.5
21.8 10
80.6
9.4
0.90
100
100
100
32.6 10
30.4 10
83.0
7.0
0.92
44
100
65.0
49.8 10
21.8 10
91.6
-1.6
1.02
100
100
100
CS
C
 1
S
C
27.5
, is a measure of reserve capacity. The lower CU, the greater the reserve
capacity
2006 Annual Meeting - Panel 5: Emerging Technologies
Evaluation
Cycle
Utilization
Better
Solution
1
0.7
C = 90 sec.
2
Configuration 1
3
0.9
Configuration 2
4
0.8
1
5
2
6
3 7
1.0
4
Locus of Optimal Solution
Configuration 1
8
5
Configuration 2
Oversaturated
1.1
0
20
40
60
80
100
Percent
Left-Turns
Protected
Operations/Safety Metrics
2006 Annual Meeting - Panel 5: Emerging Technologies
Summary
1.
We can evaluate combinations of
approach configurations, signal phasing
and timing plans for different time
periods.
2.
We can extend adaptive control to
include dynamic lane allocation
responsive to changing traffic demand
patterns over the course of a day.
2006 Annual Meeting - Panel 5: Emerging Technologies