- Major infrastructure projects require careful integration into existing road networks to avoid traffic issues. Traffic modelling is key to assessing how projects will impact network performance. - The M4 Widening project developed a Road Network Performance Mitigation Plan using traffic modelling to identify intersections requiring mitigation before and after opening. - Traffic modelling of the CBD and South East Light Rail project evaluated the project's impact on traffic volumes, speeds and delays at a network and intersection level to ensure smooth integration.

1. Integration of mega projects into the existing road
network – the critical role of traffic modelling
Craig McGeoch
Principal Manager, Road Network Analysis

2. • Major projects and the ‘Wave’
• Integrating projects into the existing network
– the role of Roads and Maritime
– measuring integration / network performance
• The role of traffic modelling
– some key issues
• Case studies
– M4 Widening Road Network Performance Mitigation Plan (RNPMP)
– CBD and South East Light Rail (CSELR)
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This presentation

3. NSW Roads Infrastructure Pipeline
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1. Mega projects
• Roads engineering
construction in NSW is
picking up, led by the
‘mega road projects’
– NorthConnex
– WestConnex Stage 1
– WestConnex Stage 2
– WestConnex Stage 3
– Western Sydney Airport Roads
– then also…
– Western Harbour Tunnel
– Beaches Link
– F6 Corridor

4. NSW Roads Infrastructure Pipeline
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2. The Wave
• But it is not just the
mega projects…
• Major project capital
expenditure is
expected to more
than double to $16
billion in the next five
years to transform the
State’s roads, freight
and maritime network

5. Roads and Maritime Services
1. To build, manage and maintain the
state road and waterway network and
assets.
2. To maximise the customer benefits and
service potential of our networks.
3. To integrate our networks with
private motorways, local roads and
the broader transport system.
4. To use our networks to facilitate
economic and social development and
growth in NSW.
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Roles

6. The Role of Traffic Modelling
• Traffic modelling is increasingly being used to justify and prioritise
investment in transport infrastructure:
– business cases
– capacity design / project scope
– environmental evaluations
– economic evaluations (road user benefits)
– financial evaluations
– construction impacts
– etc.
• Projects of all scales:
– pinch point programme
– mega projects e.g. WestConnex
• Guidance: Roads and Maritime Services
Traffic Modelling Guidelines
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7. How is ‘Integration’ Measured
• Major projects may introduce new impacts:
– a light rail line through an existing intersection(s)
– a motorway connection to an existing arterial road
• What are the desired (‘target’) criteria for network performance
– Level of Service (and what Level of Service: C?, D?)
– already congested locations?
• What is the area of project influence?
- - - - - - - - -
• Traffic modelling is essential to assess forecast network performance
• Challenges – future year operational models in congested areas
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8. Case Study – M4 Widening
• A major investment in
Sydney’s road
infrastructure by the
NSW and Australian
governments:
– the largest urban road
project currently underway
in Australia
– comprises a series of
interconnected motorways
and road upgrades,
enhancing and extending
the M4 Motorway from
Parramatta to Sydney
Airport, and duplicating the
M5 East corridor
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WestConnex

9. M4 Widening
• Stage 1: Parramatta
to Haberfield will be
completed in two
sections:
– M4 Widening to four lanes
in each direction for 7.5km
between Church St,
Parramatta and Homebush
Bay Drive
– M4 East – widening 1km
and new 5km 2x3 lane
road tunnels linking the M4
at Homebush Bay with
Parramatta Road and City
West Link at Haberfield
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‘Stage 1a’ of WestConnex Project

10. M4 Widening
• Director General’s requirements for EIS:
– Induced traffic!
• State significant infrastructure (SSI) Instrument of approval:
– Condition B15: Within 12 months of approval*, the Proponent shall develop a Road
Network Performance Mitigation Plan
• updated consideration of potential mitigation measures to manage any predicted traffic
performance deficiencies
• justify why the predicted ‘do minimum’ performance of any intersection of the adjoining road
network cannot be maintained (if necessary)
– The purpose of the plan is to manage the performance impacts of the SSI on the
adjoining road network by identifying or confirming mitigation improvements that
could be required in areas where traffic performance may be unsatisfactory at time
of completion of construction
* i.e. prior to opening of the project
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Planning Requirements

11. M4 Widening
• Instrument of approval:
– Condition E6: At 12 months and 5 years after the commencement of operation the
Proponent shall prepare an Operational Traffic Performance Review
• assess traffic and road network performance and the mitigation measures identified in the
RNPMP
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Ongoing Requirements

12. Developing the M4W RNPMP
• Key intersections identified
• LinSig and SIDRA analysis
• Future volumes with M4
Widening using forecasts from
WRTM and additive method
(ref. Traffic Modelling
Guidelines)
• ‘Clusters’ of LinSig networked
intersections
• Evaluation criteria:
– Level of Service
– queues
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13. M4W RNPMP – Outcomes
• Pre-opening mitigation measures developed with the aim of maximising the
operational efficiency of the existing road network when the M4 Widening is
open to traffic
• Post opening measures will be the subject of detailed assessments
underpinned by traffic volumes recorded once the M4 Widening is open to
traffic and operating under stable conditions
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14. Case Study – CBD and South East Light Rail
• Light rail will play a central role in
the future of transport in Sydney:
– a high capacity, reliable and sustainable
mode of of public transport
– will ease pressure on Sydney’s roads by
reducing the city’s reliance on buses
– features a one-kilometre pedestrian zone
between Wynyard and Town Hall
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15. CBD and South East Light Rail
• Instrument of approval:
– Condition C16: Within 12 months of the completion of construction, the Proponent
shall commission an Independent Environmental Audit of the SSI
• assess the operational performance of the SSI against the aims and objectives for the project
• assess the environmental performance of the SSI against the predictions made and
conclusions drawn in project planning documents
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Planning Requirements

16. Modelling for CSELR
• Two-tiered approach
• Localised design issues:
– VISSIM
– LinSig
– SIDRA
– Commuter
• Broader network and corridor operations:
– Aimsun (hybrid)
– TfNSW in collaboration with Roads and Maritime
– Forecast traffic volumes from TfNSW Public Transport
Project Model (PTPM)
– SCATS operations
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17. CSELR – Outcomes
• Peak spreading necessary for 2021
modelling (esp. PM peak)
• Evaluation measures:
– global network statistics
– network traffic volumes
– network speeds
– intersection delays
• The EIS for CSELR describes that
broadly speaking, the traffic analysis
demonstrates that the CSELR project
can be introduced into the road network
without significant detrimental impact to
general traffic and buses
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18. Conclusion
• Roads and Maritime Services has an ambitious task ahead to deliver the
single largest series of infrastructure investments in the State’s history
• Planning for these mega projects must include assessment of how the projects
will integrate with the existing road network
• Traffic modelling is essential to this task
• The M4 Widening RNPMP and CSELR provide examples of the application of
traffic modelling to integrate major projects into the existing road network
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19. Questions
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Thank You