Adrian Hickford, Dr Simon Blainey and Tom Russell from the Universities of Southampton and Oxford, write for Air Quality News about the importance of tackling carbon dioxide emissions in England’s Economic Heartland.
The historically strong economic performance of England’s Economic Heartland region has brought with it increased pressure on transport, digital and other infrastructure networks, which operate close to capacity most of the time.
In addition, the region currently generates transport carbon dioxide emissions which are disproportionately higher than in other UK regions.
The EEH transport network, covering an area stretching from Swindon to Cambridgeshire, and Northamptonshire to Hertfordshire, is currently only served by north-south rail routes to and from London, leaving east-west travel underrepresented.
Tackling these issues and reaching an ambitious target of net-zero carbon emissions by 2050 is at the heart of EEH’s Draft Transport Strategy (open for consultation until October 6th, 2020).
Achieving net-zero carbon is particularly challenging for the transport sector as it is the largest carbon-emitting sector of the UK economy.
It accounted for 28% of greenhouse gas emissions and 33% of carbon emissions in the UK in 2018 and is still heavily dependent on fossil fuels. The increasing popularity of SUVs coupled with ambivalence over the merits of electric vehicles adds to the challenge.
Meeting the goal of a net-zero carbon transport system by 2050 will require a substantial change in the vehicle fleet towards zero-emission vehicles coupled with technological solutions to improve the efficiency of both individual vehicles and the road and rail networks as a whole, plus reducing the number and nature of motorised trips in the region.
Measures to change travel behaviour, such as increased travel costs or promotion of sustainable transport modes could help reduce the overall demand on the transport network. Effecting such large-scale changes to vehicles and travel behaviour will require significant effort through governance, legislation and changing public attitudes.
To help develop strategies to meet the goal, EEH, a sub-national transport body and strategic partnership, commissioned research from University of Oxford’s Environmental Change Institute who worked with University of Southampton’s Transportation Research Group in order to identify a number of pathways which would enable EEH to reach the net-zero carbon goal.
The report, Pathways to Decarbonisation, summarises research that mapped the EEH road and rail transport network and used the advanced modelling capabilities of the National Infrastructure Systems Model (NISMOD), developed by the Infrastructure Transitions Research Consortium (ITRC). The NISMOD v2 Transport Model is one of the few national-scale road traffic models capable of carrying out such sophisticated calculations and analysis.
NISMOD is the world’s first system-of-systems modelling capability and encompasses all infrastructure sectors and the interactions between them, enabling researchers to model, test and plan future infrastructure scenarios.
The methodologies and analyses have been developed to provide the evidence that decision-makers need to ensure that they are making choices that will meet their long-term goals and can provide infrastructure systems that are resilient to an uncertain future.
Previous assessments have been undertaken for the National Infrastructure Commission and to model multi-sector scenarios for the Oxford-Cambridge Arc. The methods have also been applied in developing countries and island states.
The NISMOD Transport Model forecasts the impact of various factors that influence transport demand and cost. For a given scenario the model predicts a range of metrics including traffic volumes, travel times, energy use, emissions and capacity utilisation.
The model maps 2,774 separate major road links in the EEH network, most of which are A roads, while the motorways passing through the region are also included. The model also predicts aggregate traffic levels on minor roads, so that outputs include all-road vehicle trips on the entire network, covering both passenger and freight traffic.
ITRC’s sophisticated transport analysis takes into account expected changes in society, such as population and income, variables linked to travel choices, such as travel time and cost, as well as possible future changes to the vehicle fleet, such as electrification and autonomous vehicles.
For example, the effects on travel demand of population change between 2015 and 2050 are taken into account, using accurate data of current Local Plan growth, which is collated by EEH. The modelling reflects the different patterns of growth throughout the region.
The model can also assess different scenarios of future change, allowing the University teams to test a number of pathways to determine the extent of their impact on total carbon emissions. For this assessment, it was assumed for most scenarios that the fleet would be comprised entirely of zero-emission vehicles by 2050, the pathways provided an important insight into routes to ensuring carbon emissions were reduced as efficiently as possible, as shown in the images below.
As well as providing an overall picture to be used at a strategic level, the ‘Pathways to Decarbonisation’ report also allows planners to view details such as average hourly estimates of link travel times and speeds, compared with free-flowing traffic, providing a representation of the levels of congestion within the network.
The complex computer modelling made possible through NISMOD and the Transport Model, coupled with the pathways approach adopted in the report has given EEH a much more complete picture of the possible ways to align interventions in transport, digital and energy infrastructure to the common objective of a zero-carbon transport system by 2050.
Based on the outcomes of the report, EEH has decided to combine two of the pathways modelled – ‘Highly Connected’ and ‘Policy-Led Behaviour Shift’ – to prioritise infrastructure investment through improved digital communications and embedded technologies. EEH will also look at the impact of policy levers used at a local or national level to reduce the number of car trips made within the EEH region.
Measures, which would be determined by EEH’s partners at a local or national level, could include pay-as-you-go charging, workplace parking levies, congestion charges in urban areas, or a blanket national road pricing initiative. It is inevitable that some ‘softer’ behaviour change measures will be needed to work alongside policies if they are to succeed.