Post on 25-Jun-2015
description
RAC WA Signals Efficiency Presentation
National AITPM Conference
Adelaide, SA
August 2014
2
The study examined two subject sites and looked at the Main Roads WA signal refinement processes to determine/ identify the following:
• What signalised intersection treatments are currently utilised
• What signal improvements could be achieved
• General considerations and requirements for refining SCATS signal settings
• Signal refinement methodologies
• Performance measures and evaluation of signal timing performance
• Barriers to refining signal settings
• Main Roads WA signal refinement policy, management, planning, and resources
Two subject sites were tested:
• Orrong Road Corridor
• Tonkin Highway/ Kelvin Road intersection
Project Introduction
3
Qualitative Commentary• Information gathered from the Main Roads WA workshops
and other sources was used• High level overview of the SCATS signal settings from the
input and output files was carried out
Quantitative Commentary• Micro-simulation models built with SCATS signal control• Several options tested• Morning, Midday, Evening, and Off peak periods modelled• On-site implementation and evaluation of AM and PM
periods
Methodology
4
Option Testing Plan
Tonkin Road/ Kelvin Road Quantitative Analysis
Option Option Details
Option 1 Adjust SCATS signal settings including Master-isolated operation and optimal cycle time
Option 2 Test under a Double diamond overlap phasing
Option 3 Double right turn on Tonkin Highway north approach and localised additional lane flaring on the Tonkin Highway south approach
Option 4Ultimate test, adjustment of the SCATS signal settings including Master-isolated operation, optimal cycle time, and test under a Double diamond overlap phasing
5
Percentage Change in Total Intersection Delay
Tonkin Road/ Kelvin Road Quantitative Analysis
AM Midday PM Off-Peak TotalOption 1 -5.4% -22.2% 5.7% -4.1% -2.5%Option 2 -10.8% -16.9% -5.8% -22.9% -9.6%Option 3 -57.9% -10.1% -13.0% -0.5% -35.5%Option 4 -34.3% -30.5% -16.2% -24.3% -26.8%
6
Average Speed (km/h)
Tonkin Road/ Kelvin Road Quantitative Analysis
AM Midday PM Off-Peak TotalBase 29.3 57.8 39.3 72.3 42.9Option 1 30.0 62.3 37.1 72.6 43.4Option 2 30.2 62.2 38.5 75.7 44.2Option 3 45.6 58.2 40.8 71.6 48.7Option 4 37.6 64.4 42.7 76.0 48.7
7
Indicative Queue Comparisons
Tonkin Highway/ Kelvin Road Base Model
Tonkin Highway/ Kelvin Road Option 5 Model
Tonkin Road/ Kelvin Road Quantitative Analysis
8
• Moderately high peak hour cycle times• Fixed split plan selection used in most cases• Link plans locked at times and not based on measured
flows
• Morning peak - Oats Street and Archer Street signals were the cause of westbound congestion
• Evening peak - Francisco Street signals were the cause of eastbound congestion
• Main road/side road approach delays are not well balanced
Orrong Road Qualitative Analysis
9
Option Testing Plan
Orrong Road Quantitative Analysis
Option Option Details
Option 1 Determine the optimal cycle time and refine SCATS data which will include operating incremental split selection
Option 2 Stagger the pedestrian crossing on Wright and Oat Streets
Option 3On the south approach of Francisco Place implement a left turn only with a u-turn bay on Orrong Road. At Archer Street and Wright Street implement a lag right turn. SCATS data refined.
Option 4 Testing of Oats Street under a double diamond overlap operation
Option 5 Ultimate test, as per Option 1 with further refinement to SCATS data and coordination
10
Percentage Change in Total Corridor Delay
Orrong Road Quantitative Analysis
AM Midday PM Off-Peak TotalOption 1 -17.6% 25.8% 2.2% -7.0% -4.0%Option 2 -2.4% 0.3% -7.8% 2.1% -3.7%Option 3 -15.9% 2.4% 8.5% -7.8% -4.6%Option 4 15.5% 8.0% 33.3% -2.5% 20.0%Option 5 -16.8% 18.4% -13.2% -6.7% -10.0%
11
Average Speeds (km/h)
Orrong Road Quantitative Analysis
AM Midday PM Off-Peak TotalBase 26.9 38.3 31.9 49.4 33.9Option 1 29.1 36.9 30.2 50.0 33.8Option 2 27.3 38.8 32.9 49.3 34.5Option 3 28.4 39.4 29.8 49.9 34.1Option 4 22.6 38.1 28.1 49.6 31.3Option 5 28.7 37.9 33.2 49.8 34.8
12
Orrong Road Quantitative Analysis
0 500 1000 1500 2000 2500 3000 350000:00
00:59
01:59
02:59
03:59
04:59
05:59
06:59
07:59
Eastbound Journey Times - AM Peak
BaseOption 1Option 2Option 3Option 4Option 5
Distance (m)
Trav
el T
ime
Seco
nds
0 500 1000 1500 2000 2500 3000 350000:00
00:59
01:59
02:59
03:59
04:59
05:59
06:59
Eastbound Journey Times - PM Peak
BaseOption 1Option 2Option 3Option 4Option 5
Distance (m)
Trav
el T
ime
Seco
nds
13
Orrong Road Quantitative Analysis
0 500 1000 1500 2000 2500 3000 350000:0000:5901:5902:5903:5904:5905:5906:5907:5908:5909:59
Westbound Journey Times - AM Peak
BaseOption 1Option 2Option 3Option 4Option 5
Distance (m)
Trav
el T
ime
Seco
nds
0 500 1000 1500 2000 2500 3000 350000:00
00:59
01:59
02:59
03:59
04:59
05:59
06:59
07:59
08:59
Westbound Journey Times - PM Peak
BaseOption 1Option 2Option 3Option 4Option 5
Distance (m)
Trav
el T
ime
Seco
nds
14
Summary
• Option 5, incremental split selection and optimal cycle time with refinement, has the largest improvement in terms of delay and average speed
• Option 1, 2, and 3 are considered to have performed slightly better than the base model overall
• While improvement can be found through SCATS signal settings, the current phasing setup can not be further improved.
Orrong Road Quantitative Analysis
15
Model video
Orrong Road Option 5
16
Orrong Road Option 5 Implementation Evaluation
17
Orrong Road Option 5 Model Comparison
18
SCATS Signals Summary
Summary
• Lower cycle times have reduced the modelled delay
• Incremental split selection assists in balancing delay on all approaches
• Master-isolated as oppose to Flexi-link assists performance
• Pedestrian lanterns needed at Tonkin Highway/ Kelvin Road
Some intersections are already running close to their optimal operation but many can achieve a 5-10% improvement
19
Acknowledgements
RAC WA – Anne Still, Una Mehta, and Sarah Cutter
ATS – Bill Sissons
Main Roads WA team