In order to meet the commitments made at COP21 in Paris in 2015 on the reduction of greenhouse gas (GHG) emissions and carbon neutrality by 2050, rapid transformations are required. Today, we are on a trajectory to cause an increase of 2.80C in global warming, rather than the targeted 1.50C1. Transport is the second largest emitter of GHG, accounting for 23% of emissions2. Of that, around 45% comes from cars, taxis, buses, and motorcycles3. Without radical action, it will not become possible to slow the pace of climate change and limit the negative impacts already being experienced around the world.
In the mobility field transformation is already underway. However, the decisions that must be taken today are not simple: they will have an impact on emissions tomorrow for years and even decades and should therefore come from a systemics approach, while taking into consideration the multiple stakeholders, interfacing organisations, and technical and economic questions.
Drawing on decades of practice in the planning, design, and implementation of public transport projects around the world, SYSTRA engineers are sharing their experience and systems approach through a series of articles on energy transition, the first of which looks at the decarbonisation of mobility from a broader perspective.
1 Emissions Gap Report 2022 (unep.org)
2 Global energy-related CO2 emissions by sector – Charts – Data & Statistics – IEA
3 Cars, planes, trains: where do CO2 emissions from transport come from? Our World Data
Delivering Net Zero today and tomorrow
We cannot rely on energy transition alone to decarbonise mobility. Instead, energy transition must sit alongside three other levers, all linked and interdependent: reducing demand for mobility, a modal shift towards public transport, and improving energy efficiency.
Firstly, we reduce emissions simply by reducing the number of journeys and their lengths. Travel demand management (TDM) uses data modelling, research, and multicriteria analysis to help create strategies and policies that will reduce demand for travel, or shift demand to different modes, times of the day or routes.
Secondly, the carbon footprint per passenger can be reduced by promoting public or shared transport rather than private cars.
Thirdly, improving the energy efficiency of both existing and new public transport systems delivers carbon and operational cost savings while providing the same – or better – levels of service.
Finally, there is the energy transition itself. This is not simply about easing the path from diesel to electric. New technologies and novel solutions, such as alternative fuels or hybrid systems, can help lower the carbon footprint of public transport systems in locations or situations where electrification is technically or economically not viable.
Managing urban transport demand with strategic planning
Urban transport accounts for 40% of all greenhouse gas emissions due to passenger transport and demand is set to double between 2015 and 2050 . As populations migrate to growing cities, the number of daily journeys and their lengths increase – along with the carbon emissions.
While transport planners traditionally model mobility needs to meet projected demands, the first step should be to find ways to reduce those demands. In developed countries, this usually centres on finding ways to reduce the use of private cars in order to reduce energy consumption per journey and carbon emissions.
In Ireland, SYSTRA conducted a two-year study for the Government to identify what transport measures would create the biggest impact on transport demand in the country’s five largest cities: Dublin, Cork, Galway, Limerick, and Waterford. Alongside decarbonisation, the study considered air quality, congestion, and the quality of the urban environment.
Thanks to stakeholder involvement, sophisticated mobility modelling and of the associated means of transport, and analysis against core goals and potential impacts, dozens of measures collected from international experiences were assessed and shortlisted to measures that would work for the five cities. These ranged from parking and low emission zones to next-generation technology and behavioural changes.
The study identified the three best strategies across all five cities, the most impactful of which was to embed ‘15-minute neighbourhoods’5 through national and local plans and strategies. Additionally, the study assessed and modelled a wide range of measures to calculate their impact on carbon emissions. Thus, progressive fuel taxation measures to encourage a switch from diesel to cleaner fuels could result in a 32% reduction in carbon emissions, whereas a strong behavioural change campaign to encourage people to switch to electric vehicles could deliver a 27% reduction.
5Based on the model of the quarter-hour city, where all essential services are within a quarter of an hour’s walk or bike ride.
Public transport solutions for fast-growing cities
By 2050, 2.5bn more people will be living in the world’s cities than they did in 20186.The cities that will be among the fastest growing are in Asia and Africa, often in emerging economies such as India and Nigeria.
This leaves regional and national officials in a difficult situation when making choices on public transport systems: how to select the best solution for a city that is constantly growing – and not necessarily in a controlled or predictable way.
Currently, most decisions are likely to be driven by capital cost. However, with more countries signing up to carbon reduction targets, decision-makers must now consider the impact of the strategies selected on carbon emissions and other environmental factors.
In India, where the population has tripled in 60 years with an ever-growing urban share (33% 7 in 2022), SYSTRA has worked on the definition of a national level climate change mitigation strategy that will set out how urban transport should be prioritised to reduce GHG emissions. Consultation with stakeholders from multiple central Government departments and with officials from three pilot cities – Nagpur, Kochi, and Ahmedabad – as well as other institutions related to urban transport has informed the development of the strategy.
To accompany the strategy, SYSTRA has developed a system of urban transport indicators based on accessible data that officials can easily use to help them make decision on public transport. The system was developed from an initial framework created by the global programme MobiliseYourCity (MYC), then adapted to cope with India’s fast-moving urban dynamic.
To determine the best strategic option for reducing emissions from India’s urban transport sector, SYSTRA built three scenarios, measuring the predicted GHG emissions with a specially developed tool. The most ambitious of the three scenarios would see a drastic (>40%) reduction in emissions compared to business as usual for both the passenger and logistics transport sectors.
Improving energy efficiency on urban electric railways
Although the energy consumption per passenger for journeys made by rail are lower than consumption for road modes, rail transport is still a high consumer of electricity globally. Improving the efficiency of electric railways is a lever for lowering the carbon footprint per passenger.
Studies conducted by SYSTRA indicate that substantial operational energy savings of up to 30% are possible in most cases. The cost of realising these savings will be lower if enhancements can be made during the planning and design phases, but it is also possible to improve the energy efficiency of existing rail transport systems. A knock-on effect of lowering operational costs could be lower fares for passengers, encouraging greater use of the network.
Reducing carbon emissions from mobility means encouraging more people to use the rail network by improving services and reducing fare increases, while maximising energy savings.
In Brazil, SYSTRA is advising nine urban rail operators on what energy efficiency improvement measures would enable the best return on investment.
Brazil already benefits from low carbon electricity, generating 87.7% of its electricity from renewable resources – mainly hydroelectric8.
The study carried out by SYSTRA proposes a menu of efficiency improvement options, with customised recommendations according to the type of operator and the corresponding region. These recommendations concern both the time of the solutions implementation (short, medium, or long term) a well as the capital costs involved.
The study enabled the identification of some low-cost interventions that can be implemented immediately and which will pay for themselves quickly. These include resetting timetables enhancing energy braking recovery from one train to another, more automation on equipment such as escalators and replacing lighting with LEDs. The replacement of aging rolling stock, harder to maintain, was also studied in order to improve the total cost of ownership and the quality of service.
In addition, the development and use of digital twins to monitor and optimise the performance of systems such as traction and auxiliaries such as heating, ventilation, and air conditioning. This would also allow maintenance and energy consumption to be better mapped and predicted.
Multiple innovations will drive electric bus roll-out
Originating in the 1970s in South America, bus rapid transit (BRT) systems have since spread so that today hundreds of cities operate them. With all but a handful of them powered by diesel, the challenge is to develop battery electric solutions that will allow a rapid and relatively painless transition.
Current limitations to a wider roll-out of electric bus technology include the upfront capital expenditure required, the limited range, the time required for charging, the maintenance cost and the limited life duration of the battery.
The International Association of Transport (UITP) aims to overcome these barriers via a programme of research and development, financed by the European Commission. The goals of the programme on BRT systems are to reduce GHG emissions by 70%, reduce cost per km per passenger by 10%, and total cost of ownership by 10%.
The programme will use seven cities with existing BRTs as their testing grounds for new technologies, six European cities and Bogota in Colombia. In each city different technologies will be tested by BRT operators, public transport authorities, rolling stock manufacturers and equipment suppliers in particular: from intelligent charging solutions, predictive maintenance solutions, the digital twin and real-time fleet planning.
As a contributing partner, SYSTRA’s involvement runs throughout the four-year programme, from writing specifications for innovations to be tested to reviewing those innovations at the end of their deployment within the cities. SYSTRA is also leading one of the innovation streams looking at predictive maintenance strategy, based on data collection using of Internet-of-Things (IoT) technology.
With lessons learned from all the cities involved, the goal is to deploy innovative e-BRT concepts based on selection of technologies and solutions that have proved their value and return on investment in real-life situations by 2030. A pool of nearly 30 cities have already been selected as followers or twinning cities that will be able then to pick and choose the interventions that would work best for them.
Still to come…
In the next article we will be looking at the role that clean energy plays in decarbonisation and how it is inextricably linked to the public transport sector. With the right planning, policies and technology, decarbonisation of mobility can help drive the broader transition to clean energy – another complex issue.
To find out more about UITP’s energy transition initiatives, follow this link:
Photo credits: Istock, CAPA pictures – Christian Fleury 2019