PhD student profile

About Tariq’s research

This research is fundamentally an investigation into the development and evaluation of new and innovative methods to price urban transport that would offer efficient, affordable and flexible trips while reducing reliance on private vehicle use and reducing congestion and emissions.

Specifically, this research will undertake quantitative approach which demonstrates novel use of pricing strategies and signals for managing demand and promoting low carbon mobility solutions driven by disruptive forces which are changing the mobility landscape and providing consumers with more choices to meet their transport needs.

What questions will this research answer?

1. What are the social, technological, economic impacts and trends in road network pricing, and their important role as an effective strategy for travel demand management?
2. How can the modelling frameworks of road network pricing be extended to accommodate the following issues:

• • Relaxing the inelastic transport demand constraints in peak hours by improving other modes of transport such as public transport and by diverting vehicle traffic to a multi-modal network
  • Incorporating user heterogeneity through introduction of multi-class users, differentiating user groups with different value of time in the charging technique;
  • Optimising the balance between two main pricing indicators i.e. distance and time in formulating a pricing policy;
  • Testing and evaluating a coordinated pricing scheme for multi-region networks to reduce emissions

3. Evaluate through case studies how the proposed road network pricing interventions and modern transport policies (particularly congestion charge, parking levies, low emission zones) can reduce congestion and emissions using a case study for Melbourne?

Video presentation

Why is this work important?

The successful completion of this research will provide important directions for policy making at national and state levels in Australia. This will be achieved through garnering of a global perspective and the lessons learnt from the experience of countries that have adopted road pricing, which will help Australian decision makers to better understand the challenges and opportunities that road pricing and congestion charging brings to the community.

The research will also identify potential opportunities related to policy, regulation, research and development, standards, public private partnerships, private sector investments and trials to demonstrate the feasibility of road pricing in an Australian context.

Beyond the academic contributions, this research will have wide societal impacts and in particular it will contribute to efforts to reshape transportation taxation systems by moving away from taxes on vehicles through registration fees, and towards user-pay taxations where travellers pay for the amount of travel they do or the pollution and emissions they are responsible for.

Successful completion of this project will also help in developing new opportunities for public private partnerships to deliver new mobility systems based on these disruptive forces which provide consumers with more options to replace car ownership with access to everyday low carbon transport systems. These initiatives will rely on advanced models, to be developed in this research, to determine mobility patterns under different pricing strategies.

What drew Tariq to this work?

This strategy of road pricing introduced in 1975 and has been implemented in many cities globally including Singapore, London, Stockholm, Milan and Gothenburg. Despite its significant popularity and benefits, this scheme has never been tested or implemented on ground in any part of Australia.

Traditional methods to reduce traffic congestion focus on the supply side and building more roads, which generates induced demand. However, emerging approaches focus on demand management, by reducing the need for travel. Tariq saw potential in this in improving congestion and reducing emissions. He was also drawn to the fact that his research can contribute to making these systems work in the Australian context where congestion pricing has been attracting attention from policy makers.

Results so far 

Tariq has the simulation model to test various road pricing scenarios with the results showing a reduction in traffic volumes, emissions and delay times as well as an increase in the traffic speed inside the proposed pricing zone. He has tested different pricing schemes including distance-based, time-based and a combination of both. A comparative analysis of the results revealed that the joint scheme performs better among all schemes. Various scenarios including low-cost, medium-cost, and high-cost pricing were also tested.

As would be expected, the results showed that higher cost scenarios perform better in terms of emissions and congestion reduction because fewer drivers would drive into the city when the cost is high. The findings to date shown that it is possible to achieve 7% reduction in traffic density, 20% reduction in travel time, 13% reduction in emissions as well as 3% increase in the travel speed within the proposed pricing zone.

Interestingly, results from the behavioural survey that has been conducted around “Travellers perspective on road pricing” showed that one-third of the respondents support congestion pricing as a travel demand management tool. The percentage of respondents who would support congestion pricing increased when they were informed that the congestion charge would be used to improve public transport services, reduce public transport fares and improve infrastructure for multi-modal transport.

The results, about respondents willingness to pay for a congestion charge, revealed that, in general, one-third of the sample were willing to pay. Around 40% of respondents were opposed to paying this charge and were of the view that the imposition of a congestion charge was unfair. When asked if they would support pricing as a substitute for vehicle registration fees, or if they would pay a fee if it reduced travel time then their willingness to pay increased notably (around 75% of respondents said they would be willing to pay the road user charge under these conditions).

For the respondents who were not willing to pay a charge fee, around 50% said they would use public transport instead, and around 50% also said they would change their routes by using non-priced alternative roads.

A poster for Tariq’s PhD project, made for display at the 2022 ITS Australia awards.

Reflections on his PhD

Undertaking a PhD is both a technical and emotional journey and requires considerable support. Tariq says that his weekly meetings with his principal supervisor are very helpful. The ever-ready technical and moral support from his principal supervisor, Professor Hussein Dia, helps in achieving his research outcomes.

Tariq has learned how best to pitch his research in front of academia, industry, and the general public. He has participated in Three Minute Thesis competitions, the motivation behind was to improve his communication skills. This endeavour has resulted in increasing confidence in presenting his research to technical and non-technical audiences.

A word from PhD supervisor, Professor Hussein Dia

Why is this PhD topic important to investigate?

The pricing of trips is an established and effective intervention that aims to find an equilibrium between the demand for people travel and the shipment of goods, and the provision of multimodal transportation capacity. Importantly, road pricing and congestion charging schemes are among the most promising demand management strategies that have for long captured the interest of transport economists, engineers, and urban planners as an equitable user-pay solution.

Although road pricing has been investigated for a number of decades now, the topic is receiving renewed interest because of changes in government policies, greater sensitivity to environmental issues and the pressing needs to manage the demand for travel. The topic is also gaining more support due to the rapid developments in vehicle electrification that are expected to have a significant impact on fuel excise revenue, thus prompting renewed thinking on road pricing as a replacement for fuel excise revenue generation and other charges such as registration fees.

It is anticipated that road pricing schemes will become increasingly important in the future as a transport policy tool to manage private vehicle travel post COVID-19 and as a mechanism to shift travel away from energy intensive modes of private transport towards more efficient and less polluting forms of shared public transport and active travel alternatives particularly in locations where alternatives modes of transport are well-established and can deliver efficient and cost-effective travel options.

What are the major challenges to overcome in the field?

Although the literature abounds with case studies that show the feasibility and effectiveness of road pricing and congestion charging schemes, a number of challenges and barriers still need to be overcome to allow for widescale deployment of these schemes in cities around the world. These challenges includes public and political acceptance, equity concerns and privacy. Acceptance of road pricing schemes is critical for their successful deployment and can be a major impediment to deployment. In almost every city where road pricing was implemented, governments faced public resistance.

Numerous factors influence public acceptance, including privacy, equity, scheme understanding, complexity of implementation, distrust in governments’ intentions, and uncertainty about benefits. The privacy concerns are related to sharing personal information in automated payments, and infringements of privacy. In cities where these concerns were adequately addressed, genuine efforts were made and appropriate measures were put in place to deal with them. The equity concerns are related to impacts of road pricing on low-income and vulnerable groups who may not be well-served by reliable public transport or other alternative modes of travel. These issues are addressed by ensuring equal access to public transport and system design that does not discriminate against vulnerable segments of society. Another concern with public acceptance is perceived complexity of pricing schemes. Information campaigns about how they work can help increase awareness.

Additionally, uncertainty about a scheme’s effectiveness in reducing congestion and revenue allocation can reduce public confidence. This can be addressed when generated revenue is directed to improve public and active transport initiatives. Finally, and given the pandemic situation and the decline in public transport patronage, there are already signs of increased road congestion with more people choosing to use their private vehicles instead. If this trend persists, congestion will worsen, and emissions will increase, in which case the justification for road pricing would be more pressing than ever before. More research is needed over the coming years to understand the drivers of travel change after the pandemic with a particular emphasis on determining the role of pricing in curbing the demand for private vehicle travel.

Where might this work lead in the near (and far) future?

Despite public and political resistance to user-pay transport solutions such as those offered by road pricing and congestion charging schemes, it is anticipated that with better information dissemination about their benefits, more cities would adopt these schemes in the future.

Our current research on the topic aims to understand key success factors that can lead to equitable deployment of such schemes in the Australian context. There is sufficient evidence in the literature that road network pricing is increasingly becoming the focus of ignited deliberation on transport taxation reform and rethinking of approaches that raise revenue to maintain and upgrade the infrastructure required to support a city’s mobility needs.

Today’s transport infrastructure funding models, which are grounded in raising revenue from vehicle registrations, fuel excise, and license fees, are inequitable. Going forward, revenue from these schemes will not be sufficient to meet future infrastructure expenditure requirements. They will also face increased pressure as transportation revenues decline as consumers shift to electric vehicles and fuel-efficient vehicles.

Another key consideration in the future is that road network pricing should be viewed as an integral part of a broader taxation reform that would eliminate or restructure other transport taxes, such as vehicle registration fees that are unrelated to the amount of travel. Importantly, research on this topic also shows that future policies should ensure that the revenue generated by user fees would be used to fund initiatives that would increase public transport usage, maintain and operate roads and transportation services, and improve travel options.

The importance and urgency of implementing road pricing as a solution to reduce emissions, particularly in congested urban areas, will also become more prominent going forward as many cities and nations push to achieve net zero emissions by 2050.

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Publications

Munir, T., Dia, H. & Ghaderi, H. 2021. A Systematic Review of the Role of Road Network Pricing in Shaping Sustainable Cities: Lessons Learned and Opportunities for a Post-Pandemic World. Sustainability, 13, 12048.