Transport, Traffic, and Roads

TRANSPORT, TRAFFIC AND ROADS


Have We Been Had?


The CWWPA has been concerned for some time that the approval by Willoughby City Council of ever more major developments in the Chatswood CBD seems to proceed without consideration of the accumulated impact of new residents’ vehicles on local traffic flows and congestion. 


Council has indicated that developers are only required to take into account the traffic impacts of vehicles from isolated developments as they flow into the street where the development is built.  Their impact on traffic flow on adjacent streets – many of which are already congested at different times of the day – is not taken into account.


One of the documents on which WCC has depended in its planning is the Arup Future Conditions Report (2020).  CWWPA Committee member, Andrew Nelson, recently delved into this report to see what it said about local traffic projections and found much to concern him.


Council’s Arup Future Conditions Report – a complete farce?


Council and Developers produced the Arup Future Conditions Report in 2020 to show that planned future residential (a doubling of the current population), retail and commercial development in Chatswood’s CBD would not have an adverse effect on traffic through the precinct.


Check for yourself


Below is a traffic flow map (numbers adjacent to streets show volumes of road traffic, am peak) from the Arup Report showing a modelled 2026 traffic case. The streets used in the study are those coloured or darkened, with adjacent modelled traffic flow numbers. Some street/road names have been added for clarity. With your knowledge of the Chatswood CBD and surrounds, how many errors can you spot?




The map is reproduced below with a number of errors marked.

Starting from the top and working south noted errors are:

Those with sharp eyes possibly found more.

Test the maths

The study in part models predicted traffic flows for 2026 and 2036 using Transport for NSW (TfNSW) base predicted population/traffic data, and Willoughby Council (WCC) predictions of population growth in Chatswood to arrive at future predicted traffic flows. Note that these relate only to am peak time.

 You don’t have to be a traffic flow modelling expert to do some simple checks on the results. Looking at the traffic flow figures on the map above, one would expect Victoria Ave (east) to be the busiest, most congested road in Chatswood (excluding Pacific Highway and Mowbray Rd). But you have probably never seen Victoria Ave (east) congested. Look at the northbound traffic figures for the Pacific Highway adjacent to Victoria Ave. These figures reduce from 2710 south of the Victoria Ave intersection to 1837 north, so most of the traffic modelled in Victoria Ave going east (1408 vehicles) has come from northbound Pacific highway traffic. The Pacific Highway/Victoria Ave intersection is controlled by lights. Observation of these in weekday peak hour shows that one complete cycle takes 2.5 minutes, of which 20 seconds are allocated to traffic turning right into Victoria Ave from the Pacific Highway. Generally, about 10 cars manage to turn in that time (max 12). Simple maths show there are 24 light cycles in an hour, so about 240 cars can get around. In addition, observation showed about 2 Pacific Highway south bound cars per cycle turning (48 in an hour), so about 284 cars/hr in all. Well short of the modelled 1408 vehicles.

This is only a small taste of the problems with the Arup Report, but enough to raise doubts about the rigour applied to the traffic modelling. In the minds of some, the vehicle traffic portion of the report has no validity whatsoever.

Council’s key response to traffic concerns

WCC quoted the Arup report several times in its December answers to residents’ concerns about traffic arising from future residential, retail and commercial development of the Chatswood CBD following the exhibition of the Chatswood CBD Planning and Urban Design Strategy and draft LEP/DCP last year. Those who believe the vehicle traffic portion of the report to be invalid thus believe also that the Council response to residents’ questions is invalid, and the question of traffic should be revisited.

More on the Arup Report and its background

The Chatswood CBD Planning and Urban Design Strategy (CCPUDS) – a key document

For some years Willoughby Council has been involved in a process of redefining Chatswood’s CBD area and changing environmental, planning and building regulations to allow an approximate doubling of residential accommodation in the CBD population, from around 12,000 to 24,000. This will be accompanied by a significant increase in commercial and retail space. At the heart of this process is the Chatswood CBD Planning and Urban Design Strategy (CCPUDS) document. The purpose of CCPUDS is to provide a strong framework to guide all future private and public development in Chatswood CBD over the next 20 years.

 An early draft of CCPUDS, which includes a significant section on the traffic impact of the proposed changes, was produced by Council and consultants and presented to Councillors in June 2017. It includes statistics that suggested that the proposed densification could result in more than 9,000 additional cars accommodated in new high-rise residential and commercial buildings’ car parks. The report acknowledged the existing presence of a number of large car parks, and that the road system is heavily utilized seven days a week for access to retail parking. Although existing congestion was not specifically mentioned, a number of strategies were suggested to minimize the number of new car parking spaces to be provided, encourage alternative forms of travel, and encourage through traffic to bypass Chatswood. At its June 2017 meeting Council voted to endorse the various recommendations of the CCPUDS document and “forward for endorsement to the Department of Planning and Environment (DPIE), and the Greater Sydney Commission North District Commissioner”.

Traffic study required, paid for by developers, but Councillors kept in dark

In August 2019 DPIE wrote to Council requiring a traffic study be prepared before full endorsement of CCPUDS. Subsequently Council staff, without the knowledge of Councillors, and in conjunction with Traffic for NSW (TfNSW) and 4 developers who had existing planning applications, arranged for a traffic and transport study, the Arup “Future Conditions Report”. This was paid for by developers.

The study commenced in January 2020 and was completed in September 2020. In July 2020, prior to completion of the Arup Report, DPIE wrote to Council noting that previous concerns, including traffic, were “capable of being addressed”, and fully endorsing the CCPUDS document. Armed with this endorsement, and still before the Arup report was finalized and viewed by Councillors, Council was asked at its September 2020 meeting to note the DPIE endorsement of CCPUDS so that public exhibition and consultation could proceed.

Quality control – peer review confidential

For quality control the Arup Report was to be peer reviewed by TfNSW. In response to a recent request to Council to see the review, Council advised that the review was confidential.

 The new CCPUDS – reduced traffic references

A new CCPUDS document was produced in September 2020. The topic of car traffic volume was reduced to three sentences: “The CBD Strategy employs a Travel Demand Management approach seeking to modify travel decisions to achieve more desirable transport, social, economic and environmental objectives consistent with Council’s Integrated Transport Strategy”,  “Car parking should be reduced consistent with the objectives of Council’s Integrated Transport Strategy and in accordance with any future revised car parking rates in Councils DCP”, and “Other strategies for car parking reduction include reciprocal arrangements for sharing parking and car share”. The Arup report is only mentioned as “The Strategy is supported by transport and traffic input from Arup”, but the report is not specifically referenced.

 CCPUDS exhibition and Q&A

In March 2022 the draft new LEP/DCP documents and CCPUDS went on public display for public feedback by way of submissions. In addition, Council held public webinars with the different Council Wards to summarise to residents the changes and impacts of the proposed new planning documents. As part of each Webinar a Q&A session was provided. In response to a question “What is the town planning to create more parking and reduce congestion?” Council did not mention the Arup report, but referenced the concept of ‘transit oriented development’ whereby new development was in proximity to railway/metro stations and existing CBDs and local centres, and “the overall intention is that residents and workers in these areas will be able to walk, cycle or use public transport for a greater proportion of their trips, instead of private car. This will not only minimise further travel by private car and traffic congestion but also contribute to greater health and wellbeing, lower emissions and greater amenity in general”.

In response to an individual query on the traffic question to a local Councillor, the reply was “In a nutshell, to my knowledge there is no comprehensive cumulative study on traffic impacts specifically related to planning proposals.  TfNSW only consider each proposal in isolation.  The closest you will find is what we have laid down in the traffic and transport strategy, but the specifics of planning proposals are only reviewed in isolation.  Our officers do their best to consider the impacts as a whole, but the planning proposal proponents have the right to have their proposal considered in isolation – this is the way the law works and the way the system is set up.” The Arup report, which was pertinent in response to the traffic query, was not referenced.

Chatswood West Ward Progress Association (CWWPA) submission, Arup report emerges

Chatswood West Ward Progress Association (CWWPA) made a submission to Council in relation to the CCPUDS draft LEP/DCP exhibition which included questions and comments on traffic issues. The timetable for Council to respond to submissions was October 2022, but Council’s response was not available until the afternoon of December 7th. In reply to CWWPA’s (and others’) traffic questions, Council quoted the Arup report: “Consultants Arup were engaged to complete the Future Conditions Report (September 2020). This report concluded that the CBD transport network (including the road network) could accommodate the growth planned for in the Chatswood CBD Strategy by implementing a variety of measures to achieve the mode shift as part of Council’s stated TDM (Traffic Demand Management) approach”. This reference to the Arup report (one of several in the same document) was the first time since its 2020 publication that Council had quoted the Arup report, to the writer’s knowledge, in response to questions about traffic implications of CCPUDS and proposed new LEP/DCP. Only five days later, on 12th December, and despite requests to postpone the vote, Council voted to endorse the CCPUDS and LEP documents for forwarding to DPIE and eventual legislation.

 A flawed report – invalid Council response to traffic concerns

The Arup Future Conditions Report – Chatswood CBD Strategic Study is immediately obvious as a flawed document to anyone familiar with the streets and traffic of Chatswood. Arup itself acknowledges that it does not address the likely times of the greatest volumes of traffic on Chatswood’s streets – when car parks empty, and on weekends – but addresses only week day am peak traffic. Those who visit Chatswood CBD in the weekday am “peak time” know that it is the best time to get into and out of the CBD quickly, and is a completely different kettle of fish to the real CDB peak times. This is acknowledged in one consultant’s report “An assessment of the preferred vehicle access option for the weekday PM and Saturday lunchtime peak hour is provided in the following sections. As agreed with TfNSW and Council, the AM peak hour has not been assessed, noting that the majority of surrounding land uses are retail and do not generate as much traffic earlier in the day”.

The street map used to model traffic flow contains glaring errors, showing street extensions that do not exist, streets that do not exist, street connections that do not exist, and a street passing through a car park. Only parts of some streets are used when it seems clear that the whole street could/should have been used.

While the report mentions that not all Chatswood Streets are used in the modelling, it never mentions that the Pacific Highway and the railway line present significant restrictions on east-west traffic, nor that the Pacific Highway is divided for its length, meaning that several streets in the study area are left turn in, left turn out only, and resulting in significantly longer journeys, leading to additional congestion, for traffic seeking turning options to reach destinations.

Traffic flow volumes on some streets are plainly wrong, and on others highly improbable. The street with the modelled highest traffic volume in the CBD is not one of the more likely arterial roads such as Albert Ave or Archer St, but a more minor street. This apparent anomaly is never commented on in the document. There is no attempt to compare modelled flows with actual measured flows, nor to do any form of reality checking at all.

The report uses a future population model with greatest increase skewed to the eastern portion of the CDB (an area around Chatswood Chase). This does not seem to be in accord with actual building site availability or planning proposals. This seems to be the reason for the report’s key finding in relation to congestion on a specific street: “In 2036, it indicates that loading of the eastern side of the precinct could lead to Victoria Avenue becoming congested.” Tell that to the shoppers.

The Arup report and current CCPUDS document can be downloaded here: https://www.willoughby.nsw.gov.au/Development/Plan/Planning-Rules/Planning-Strategies#section-5

The 2017 version of CCPUDS can be found on Council’s website as attachment 1A to the Agenda of the June 2017 Council Meeting. Meeting minutes and Agendas can be found here https://www.willoughby.nsw.gov.au/Council/Council-meetings/General-Council-Meetings