Chapter 3: Future emissions impact of transport interventions

Chapter 3: Future emissions impact of transport interventions

3.1 Background

This chapter lists those transport interventions, whether devolved or reserved to the UK/EU, which are firm commitments and are expected to have a direct and significant impact on Scottish transport emissions after the time period captured by the GHGI (1990-2011). The interventions are separated between infrastructure projects and those that involve fiscal policy or regulation. Emissions impacts are taken from the original appraisal report or subsequent published document, where available, and have been rounded to the nearest 1 kilo-tonne of carbon-dioxide equivalent (ktCO2e) where appropriate.

As well as reporting the emissions impacts, where possible the chapter outlines the general methodological approach for estimating the impact of both infrastructure projects and fiscal/regulatory policies. As independently commissioned projects, the precise estimation methodology may differ significantly depending upon the type of intervention and the original model used. Emissions estimates are frequently assessed in isolation, and so will not necessarily include the full interactions between measures or take account of the impact of any future measures on the project. Furthermore, for many interventions there are likely to be a number of localised impacts which may not be captured or presented consistently between appraisals. Where possible, the impacts presented here are the net emissions impact at a national level.

As a result of such methodological variation, the emissions estimates and related timescales are to be used as an informative guide to the direction of change and the order of magnitude only. The comparison, addition or netting off of emissions estimates between interventions or against the GHGI data is not statistically valid and may lead to incorrect conclusions being drawn.

3.2 Infrastructure projects


Environmental impacts of infrastructure projects are taken from the latest available project documents. In most cases this will be the emissions estimate contained in the project specific Environmental Statement. Some recently announced projects will though not yet have begun a formal appraisal process. For reference, links to the project home page are also provided where an online assessment is available.

STAG recommends that greenhouse gas emissions from road traffic are calculated according to the methodology in the Design Manual for Roads and Bridges27 (DMRB). DMRB was first introduced in 1992 in England and Wales, and subsequently in Scotland and Northern Ireland. It provides a comprehensive manual system which accommodates current Standards, Advice Notes and other published documents relating to Trunk Road Works.

For emissions associated with the running of diesel and electric trains, STAG recommends the use of the Rail Emission Model Final Report28 that was produced for the Strategic Rail Authority. This is published on the Department for Transport website, and provides estimated emission factors and detailed data for individual diesel and electric train types.

There are no such established guidelines for estimating carbon estimates for other travel modes. Where projects do concern other modes, for example the Edinburgh Tram, the methodology used to estimate the carbon impact is tailored specifically to that individual project. Similarly, it is important to note that when considering the predicted emissions impacts of these infrastructure projects, the modelling procedures used to derive these predictions can differ significantly, particularly in the way in which they account for secondary impacts such as land-use changes resulting from the transport project. The Edinburgh tram model is an example where the secondary effects are assessed, and this may be one of the reasons why the assessment suggests an overall emissions increase.

Undertaken by Transport Scotland and announced by The Minister for Transport, Infrastructure and Climate Change in December 2008, the Strategic Transport Projects Review (STPR)29 sets out the strategic transport investment priorities for the next twenty years and provides the basis on which Ministers can make informed decisions about future transport spending beyond the current programme. The nature of this publication means that many of the projects will be undertaken at a future date and thus lack a designated timetable and a formal appraisal process. Those projects that are being 'fast-tracked' (i.e. the Forth Replacement Crossing and Edinburgh-Glasgow (Rail) Improvements Programme) are assessed and there impacts included in the CAT. Other individual projects from within STPR likely to have a significant emission impact will be included in the CAT commentary as and when they become committed schemes.


A75 Dunragit Bypass

  • Document: Environmental Statement, Young Associates / Mouchel Parkman
  • Anticipated construction completion: 2014
  • Estimated emissions impact: +4ktCO2e p.a. from 2022

Drivers currently experience limited overtaking opportunities along much of the A75, which leads to traffic congestion and creates driving conditions which lower average speeds and increase driver frustration and the potential for accidents. The proposed scheme will comprise an off-line road alignment and, in accordance with its stated objective, will provide guaranteed overtaking in both eastbound and westbound directions. The additional CO2e emissions are expected as a result of the increase in distance that vehicles will travel due to the addition of the bypass.

M8, M74 and M73 Improvements

The current programme for the M8 M73 M74 Motorway Improvements is due for completion in spring 2017, with main construction works programmed to commence early in 2014, subject to contract being finalised. This project bundles together three individual projects: M8 Baillieston to Newhouse, M74 Raith Interchange, and M8 M73 M74 Network Improvements.

The project is of a similar scale to the recent M74 completion which directly supported 900 construction jobs - the large majority of the workers employed came from the local area - and is expected to reduce the journey time for the 115,000 vehicles that use the busiest sections of the M8 each day.

It is predicted that the scheme will lead to a reduction of more than 100 accidents per year and more freely flowing traffic on these strategic routes will reduce the emissions associated with queuing traffic and improving both air quality and health.

M74 Raith Interchange

  • Document: Environmental Statement (2007), Mouchel Fairhurst JV
  • Anticipated construction completion: 2017
  • Estimated emissions impact: +10ktCO2e p.a. from 2017; +10ktCO2e p.a. from 2020

The scheme is aligned with the M8 Baillieston to Newhouse works and the Associated Network Improvements. These are vital links in the trunk road network of Central Scotland and serve substantial existing developments as well as some of the most significant future development sites in Scotland.

Severe traffic problems exist at Raith Junction due to the interaction of heavy turning volumes from the A725 and the M74 at the signalised roundabout. This scheme aims to relieve traffic congestion at the junction.

M8 Associated Network Improvements

  • Document: Environmental Statement, 2008 (Mouchel Fairhurst JV)
  • Anticipated construction completion: 2017
  • Estimated emissions impact: +; +2ktCO2e p.a. by 2020

This scheme comprises capacity improvements on sections of the M73, M74 and M8 adjacent to Baillieston and Maryville interchanges as a result of changes to east-west traffic patterns once the extension to the M74 and improvements to the M8 are in place. The scheme will be procured as a package with the M8 Baillieston to Newhouse Scheme and M74 Raith Junction.

M8 Baillieston-Newhouse

  • Document: Environmental Statement (2007), Mouchel Fairhurst JV
  • Anticipated construction completion: 2017
  • Estimated emissions impact: +30ktCO2e p.a. from 2017; +30ktCO2e p.a. from 2020

This project is a proposal to upgrade the existing A8 between Baillieston and Newhouse to dual three-lane motorway standard equivalent.

The DMRB was used to calculate the change in greenhouse gas emissions, therefore the assessment has included all traffic on the entire modelled network, not just links that were explicitly included in the local assessment. The increase in emissions is due to an increase in predicted traffic levels.

A90 Aberdeen Western Peripheral Route (AWPR) and A90 Balmedie-Tipperty

  • AWPR Document: Assessment of Effects of Updated Traffic Model submitted for PLI (2008), which updates previous source of 2007 Environmental Statement, Jacobs
  • Balmedie - Tipperty Document: Environmental Statement (2007), Grontmij / Natural Capital
  • Anticipated construction completion: It had been hoped to start construction of the AWPR in 2011 however, legal challenges submitted to the Court of Session challenging the decision to proceed with the project will delay construction until resolution of the challenges. AWPR has now been combined with B-T to form one project.
  • Estimated emissions impact for AWPR: +8ktCO2e p.a. from 2012; +10ktCO2e p.a. from 2027. NO estimates available for Balmedie Tipperty

A peripheral route around Aberdeen is proposed to reduce the high volumes of traffic using the A90 in the centre of Aberdeen, and to reduce the traffic congestion that the city experiences as a result of the volume of traffic using the A90 and its associated radial roads. The overall increase in the number of road vehicles, however, is expected to lead to an increase in carbon dioxide emissions.

The AWPR will provide substantial benefits across the whole of the North East of Scotland and will provide a boost to the economy; increase business and tourism opportunities; improve safety; cut congestion as well as increasing opportunities for improvements in public transport facilities.

This proposed dualling of the A90 between Balmedie and Tipperty will provide continuous dual carriageway between Aberdeen and Ellon, which will remove the bottleneck caused by the existing single carriageway. The local community has been pressing for this upgrade for a number of years. The increase in emissions through Balmeddie -Tipperty is due to the increase in the road sections that make up the total road assessed.

Forth Replacement Crossing

  • Document: Environmental Statement (2009), Jacobs Arup
  • Anticipated construction completion: 2016
  • Estimated emissions impact: +20ktCO2e p.a. in 2032

The Forth Replacement Crossing (FRC) is a major road infrastructure project being delivered by Transport Scotland. The project was driven by uncertainty over the future viability of the existing Forth Road Bridge, and is designed to safeguard this vital connection in Scotland's transport network. It comprises a new cable-stayed bridge across the Firth of Forth, to the west of the existing Forth Road Bridge, and associated new and improved road infrastructure to the north and south of the bridge. The proposed scheme will retain the existing Forth Road Bridge as a public transport corridor for use by buses, taxis and other specified users and for continued use by pedestrians and cyclists. The new bridge will be used by all other traffic including private cars and heavy goods vehicles. Emergency vehicles will be able to use either bridge.

The FRC was identified as a key strategic investment project in Scotland's national transport network in the Strategic Transport Projects Review (STPR) undertaken by Transport Scotland in December 2008, and the National Planning Framework (NPF2) published by the Scottish Government in June 2009. There are eight specific transport planning objectives for the FRC which have underpinned the work on the proposals. These are to:

  • maintain cross-Forth transport links for all modes to at least the level of service offered in 2006
  • connect to the strategic transport network to aid optimisation of the network as a whole
  • improve the reliability of journey times for all modes
  • increase travel choices and improve integration across modes to encourage modal shift of people and goods
  • improve accessibility and social inclusion
  • minimise the impacts of maintenance on the effective operation of the transport network
  • support sustainable development and economic growth
  • minimise the impact on people, and the natural and cultural heritage of the Forth area.

Construction commenced in 2011 and that the FRC remains on target to open late 2016.

Dualling of A9

  • Document: Environmental Statement: not yet available
  • Anticipated construction completion: 2025
  • Estimated emissions impact: not yet available

This programme will address issues of driver frustration on the A9 caused by the limited guaranteed overtaking opportunities that current exist, resulting in improved connections between Perth and Inverness. Options for the proposed dual carriageway are currently being developed but it is likely that it will largely comprise on-line widening due to the environmental and physical constraints in the corridor.

It is too early to say how CO2e emissions may change as a result of the scheme. Further work will be undertaken during the design development to understand changes to vehicle speeds and their consequences for emissions before and after the scheme is in place.

Dualling of A96

  • Document: Environmental Statement: not yet available
  • Anticipated construction completion: 2030
  • Estimated emissions impact: not yet available

This programme will address issues of driver frustration on the A96 caused by the limited availability of overtaking opportunities. It will also address issues of community severance by introducing bypasses to communities along the route. Both objectives will serve to improve connectivity between Inverness and Aberdeen. Baseline information and constraints mapping is currently being collated to support future option development for the proposed dual carriageway.

Given the likelihood of extended lengths of dual carriageway to provide bypasses it is likely that CO2e emissions will increase as a result of the scheme. However further work will be undertaken during the design development to understand changes to vehicle speeds and their consequences for emissions before and after the scheme is in place.


Borders Railway

  • Document: Borders Railway Design Development Appraisal (2008), Transport Scotland
  • Anticipated construction completion: 2014
  • Estimated emissions impact: Cumulative impact of 32ktCO2e by 2030, 2ktCO2e by 2050 and -29ktCO2e by 207030.

This project is to reinstate part of the former Waverley rail route from the Scottish Borders to Edinburgh.

The change in CO2e emissions has been calculated in line with STAG guidelines. For road traffic, the calculations are based on changes to the number of car journeys between the different stations, with each journey modelled separately. The emissions from the railway have been calculated in line with the Rail Emissions Model produced by the Strategic Rail Authority.

Overall, the Borders Railway Project will have a beneficial impact on CO2e levels but most recent assessments suggests that it will see a small net increase in emissions in the early years before removing approximately 29ktCO2e over the appraisal period to 2070.

Edinburgh-Glasgow (Rail) Improvements Programme

  • Document: Edinburgh Glasgow Improvement Programme (EGIP) Appraisal and Analysis Model (2013), Transport Scotland
  • Anticipated construction completion: Phased to 2016
  • Embodied carbon emissions: +112ktCO2 (Phase 1 only) or +157ktCO2 (Phase 1&2) from construction and rolling stock provision
  • Operational emissions 31 :
    • Average annual savings of -28ktCO2 (Phase 1 only) or -30ktCO2 (Phase 1&2) p.a. from 2017
    • Cumulative savings of:
      • -234ktCO2 (Phase 1 only) or -236ktCO2 (Phase 1&2) by 2025.
      • -946ktCO2 (Phase 1 only) or -995ktCO2 (Phase 1&2) by 2050.
      • -1,743ktCO2 (Phase 1 only) or -1,843ktCO2 (Phase 1&2) by 2075.

This intervention was identified early in the STPR and brought forward in a study which considered improvements to the capacity, frequency and journey time of rail services between Edinburgh and Glasgow.

The change in CO2e emissions has been calculated in line with guidance from the Department for Energy and Climate Change. Previous estimates derived from the Network Modelling Framework (NMF) have been significantly revised to reflect the latest operational assumptions for the programme. There is estimated to be a reduction in road emissions of around -3ktCO2e p.a. which is included in the overall figures presented.

The Edinburgh Glasgow Improvement Programme is expected to result in a significant reduction in emissions, through the electrification of approximately 350 km of single track and the resulting move from diesel to electric trains. The programme therefore achieves its emissions reductions reported here through transferring emissions from the non-traded sector to the traded sector, as demonstrated in the table below. If electricity emissions and those from embodied carbon are included, the total net impact of EGIP is -1,116 (-1,114 for Phase 1 only) ktCO2e by 2075. Of this total, -1,669 ktCO2e arises from diesel savings from trains removed from the network (same value for Phase 1 only), -174 (-74 for Phase 1 only) ktCO2e from cars removed from the road network, and +570 (518 for Phase 1 only) ktCO2e from the new electric trains added to the network. Table 4 demonstrates the precise breakdown of the emissions impact across the different sectors.

Table 7: Change in emissions from EGIP (Phase 1&2, 'Phase 1 only' impact in brackets) by sector (ktCO2e)
Budget Period Operational Embodied**
Transport sector Non-transport sector*
2013 - 2017 -17 (-17) +16 (+16) +105 (+105)
2018 - 2022 -132 (-132) +129 (+129) +7 (+7)
2023 onwards -1,694 (-1,595) +425 (+373) +46 (+0)
UK Net -1,843 (-1,743) +570 (+518) +157 (+112)

* Electricity production and distribution sector
** Primarily manufacturing and construction

Edinburgh Tram Lines 1a and 1b32

  1. Document: STAG part 2 appraisal (2006), Steer Davies Gleave / Colin Buchanan
  2. Anticipated construction completion: 2014
  3. Estimated emissions impact33 : +90ktCO2e p.a. from 2011; +167ktCO2e p.a. from 2031.

The proposed tram lines, Phases 1a and 1b, are covered by the respective Edinburgh Tram (Lines One and Two) Acts of 2006. Both were intended to open in 2011 but contractual disputes have caused severe delays, particularly in terms of certainty for completion and operational dates. Phase 1a, which is intended to run from Edinburgh Airport to Newhaven via Princes Street will now be partially completed from the Airport to York Place via Princes Street, and is scheduled for operations in 2014. No date has yet been set for the completion of the remaining stage(s) Phase 1b running between Haymarket and Newhaven via the Roseburn corridor has been postponed on affordability grounds.

In the project development stages, an Edinburgh based demand forecasting model was developed to predict use of the tram and the impact on other transport modes. The STAG reports that building the tram network would generate a higher level of development along the tram corridor than not building the network. The effect of this is to increase the overall volume of movements which could potentially include a higher number of car trips. The original modelling work demonstrated that both Phase 1a and 1a+1b would increase the level of CO2e, as a result of traffic re-routing and demand redistribution.34, 35

Table 5 summarises the information from the projects listed above. Whilst this is a useful reference table, it should be reiterated that these emissions estimates are not produced using a single, consistent methodology and, therefore, are not directly comparable. That said, the pattern of expected relatively small increases in emissions from road infrastructure projects (not to forget the other economic benefits delivered in respect of journey time improvements set out in the project appraisal) will be more than compensated for in the long term through the modal shift can be offset through investment in rail. The investment in the Edinburgh- Glasgow Improvement project is expected to generate annual reductions in emissions of around 30 ktCO2e in the near term from a combination of removing diesel rolling stock and displacing cars from the road.

Table 8: Emissions impact estimates of transport infrastructure projects
Project title Published emissions estimate
A75 Dunragit Bypass +4 ktCO2e p.a. from 2022
M74 Raith Interchange +10 ktCO2e p.a. from 2020
M8 Associated Network Improvements +2 ktCO2e p.a. by 2020
M8 Baillieston-Newhouse +30 ktCO2e p.a. from 2020
A90 Balmedie-Tipperty +2 ktCO2e p.a. from 2013
A90 Aberdeen Western Peripheral Road +10 ktCO2e p.a. from 2027
Forth Replacement Crossing +20 ktCO2e p.a. in 2032
Stirling-Alloa-Kincardine Railway Line +2 ktCO2e p.a. from 2009
Borders Railway +32 ktCO2e total by 2030
+2 ktCO2e total by 2050
-29 ktCO2e total by 2070
Edinburgh-Glasgow (Rail) Improvements Programme -28 ktCO2e average p.a. from 2017
-1843 ktCO2e total by 2075
Edinburgh Tram Lines 1a and 1b +90 ktCO2e p.a. from 2012
+167 ktCO2e p.a. from 2031

The emission estimates within this table are forecast changes in carbon dioxide emissions with the project compared to without the project in a given future assessment year. These estimates have been calculated using a variety of methodologies and, consequently, it is not statistically valid to aggregate the individual figures or directly compare them with one another.

3.3 Fiscal / regulatory measures

The current split between devolved and reserved powers means that the majority of fiscal and regulatory decisions that impact on Scottish transport emissions are taken at either the UK or EU level.

Those areas over which Scottish Ministers have direct control are though still extremely important, particularly in respect of behaviour change, a vital component of long term emissions reductions, and the removal of certain key barriers that could affect the significant uptake of ultra-low or zero carbon vehicles by households.

Published in June 2013, the Second Report on Proposals and Policies provides the most up to date and comprehensive analysis and assessment of these Scottish policies and the potential impact these measures can have on emissions out until 202736. The impact of tightening EU car and van emissions standards and the Renewable Fuels Transport Obligation are also covered within the RPP's analysis.

With a narrower focus on road transport emissions, and particularly on the transition from reliance on fossil-fuelled vehicles towards plug-in cars and vans, the recently published Switched on Scotland 37 sets out the necessary steps and barriers to be overcome on the pathway to the almost complete decarbonisation of road transport.

It is more difficult to ascertain the potential emissions impact of UK and (other) EU fiscal or regulatory measures in Scotland, not least because the impacts are analysed and estimated at a more aggregate level. That said, some Scottish estimates can be generated and where possible these are recorded below alongside the description of the policy intervention.

The best and most readily available sources of information for the aggregate UK emissions impacts include published Impact Assessments, associated documents accompanying the annual HM Treasury (HMT) Budget and Autumn Statement/Pre-Budget reports, HMRC notes and the House of Commons Library for more general topic background and briefing.

Air Passenger Duty (APD)

Air passenger duty (APD) is charged on all passenger flights from almost all UK airports39. The rate of tax varies according to passenger destination and the class of passenger travel. Since 1 November 2009 APD has been structured around four distance bands, set at intervals of 2,000 miles from London. The intention of the banding is that those flying further will pay more and in the latest available estimate APD was expected to deliver estimated emissions savings of 0.4MtCO2e in 2010-11 rising to 0.6 MtCO2e in 2011-12.

Following a consultation by the UK Government in 2010 it decided against switching to a per plane duty but did extend the scope to cover business jets with effect from April 2013.

APD rates were increased in line with inflation in the 2013 Budget and announced that for 2014/15 rates would rise in line with inflation from 1 April 2014. The 2014 Budget announced the abolition of highest APD bands (C and D) so that any flight to a country with a capital city more than 2000 miles from London would now be charged at the same band B rate. Very few current direct flights from Scotland are affected by this change.

Inclusion of aviation in EU ETS

The Aviation Greenhouse Gas Emissions Trading Scheme Regulations 2010 came into force in the UK on 31 August 2010. The inclusion of aviation within the emissions trading system will allow the sector to take responsibility for its carbon emissions in the most cost effective way and will form the basis for wider, global action. While it is difficult to predict the exact impact of the scheme, particularly with the ongoing economic uncertainties, earlier estimates made by the Commission suggest that the cap could reduce emissions in 2020 by up to 183 million tonnes CO2e.

In November 2012 the European Commission announced that it would "Stop the Clock" on the implementation of the "international" aspects of the Aviation Emissions Trading System. The effect of this is that only flights between European Economic Area (EAA) aerodromes need comply with the Aviation ETS. The key objective of the Commission's suspension is to encourage a wider international deal. This suspension is unlikely to have any material effect on the impact of the regulation on Scottish aviation emissions.

Fuel duty

Documents: Tax Information and Impact Note 11 December 2012; Tax Information and Impact Note published alongside 2013 Budget 20 March 2013

Implementation date: 1 January and 1 September 2013

  • Estimated emissions impact: +0.2 MtCO2e per year, +0.3 MtCO2e (UK).

To support fiscal consolidation and encourage fuel efficient behaviour Budget 2009 announced that fuel duty would increase by one penny per litre in real terms on 1 April each year from 2010 to 2013. Budget 2010 announced that the 2010-11 increase would be staged and that fuel duty will increase by a further penny per litre in real terms in April 2014. These measures were estimated to save 2 MtCO2e per year by 2014-15 compared to inflation only increases.

Due to high oil prices, Budget 2011 cut the fuel duty by one penny per litre and deferred the scheduled 2011 inflation-only increase until 1 January 2012. Subsequently, the increase of 3.02 pence per litre fuel duty increase deferred from August 2012 and due to come into effect on 1 January 2013 was cancelled and the 2013-14 increase due on 1 April 2013 was deferred to 1 September 2013. This rise was also subsequently cancelled as was the increase in the 2014 budget. Together, the removal of measures have been estimated to add 0.5 MtCO2e per annum to the UK emissions total compared to where it would otherwise have been, although this gross impact from the removal of the fuel duty rise does not take account of the dampening effect of the rise in wholesale fuel prices and therefore pump prices on demand and therefore emissions.

Reform to vehicle excise duty

  • Document: Pre-Budget Report (2009), HMT; HMRC Impact Assessment; Budget 2013 HMRC documentation
  • Anticipated implementation date: 2010
  • Estimated emissions impact: -0.9 MtCO2e by 2020

From April 2010, the Government introduced a new first-year rate of VED. Under this system, all cars emitting up to 130 g CO2e per km pay no VED in the first year. Cars emitting over 165 g CO2e per km pay additional VED in the first year. First year rates are used to encourage the purchase of more fuel-efficient cars. Together, these changes are estimated to result in a cumulative UK saving of 0.9 MtCO2e by 2020. However, this assessment only includes impacts in the new car market, and these figures will contribute to the delivery of the savings from the EU regulation on CO2e from cars, rather than constitute additional savings. Budget 2011 announced that VED rates would increase by RPI indexation in 2011-12 with rates for HGVs frozen over the period. HGV rates were subsequently frozen again at the 2013 budget while rates for cars have been increased in line with inflation (RPI) in the latest budget. Cars in Band A (<100g CO2e per km) pay no VED while those in Band B (100 - 110g CO2e per km) and C (110 - 120g CO2e per km) pay no VED at first registration and £20 and £30 respectively thereafter.

Company car tax

  • Document: Pre-Budget Report (2009), Budget 2012 HMT
  • Anticipated implementation date: Ongoing
  • Budget 2013 HMRC documentation
  • Estimated emissions impact: Not quantified

The UK Government's June 2010 budget set out further reform of company car tax to provide an incentive to purchase the lowest emitting vehicles on the market. This has been reinforced in recent budgets to incentivise the purchase and manufacture of ultra-low emission vehicles in the UK.

From April 2011, the basic threshold for the 15 per cent band of company car tax was reduced by 5 grams of carbon dioxide emitted per kilometre (g CO2e per km), so that this band applies to cars emitting between 121 and 129g CO2e per km. This threshold has subsequently been reduced further.

For 2015-16, this measure introduces two new appropriate percentage bands for company cars emitting 0-50g of carbon dioxide (CO2e) per kilometre (5 per cent) and 51-75g CO2e per km (9 per cent). In addition, as announced at Budget 2012, the remaining appropriate percentages are increased by two percentage points for cars emitting more than 75g CO2e per km, to a new maximum of 37 per cent.

Budget 2013 also sets out rates for company cars emitting 75g CO2e per km or less for 2016-17 and provides a commitment that in 2017-18 there will be a 3 percentage point differential between the 0-50 and 51-75 g/km CO2e bands and between the 51-75 and 76-94 bands. The 2014 budget further lifted the percentage of a company car list price that would be subject to tax for cars emitting more than 75 g CO2e /km.

This policy aims to encourage the purchase of ULEVs and hence contribute to the objectives of reducing greenhouse gas emissions from road transport. However, given that the market is at an early stage of development it is not possible to precisely estimate the impact on ULEV sales or emissions savings, but they are likely to be small to begin with.

Fuel benefit charge (FBC)

  • Document: Pre-Budget Report (2009), HMT
  • Anticipated implementation date: 2010
  • Estimated emissions impact: Not quantified

The provision of free fuel to company car drivers provides a perverse environmental incentive. The Government is committed to increasing the fuel benefit charge multiplier - which is used to calculate the tax payable on free fuel - at least in line with inflation each year. The Pre-Budget Report 2009 set out that from 6 April 2010, the multiplier would increase from £16,900 to £18,000. The van fuel benefit charge - on which tax on free van fuel is payable - will also increase from £500 to £550. Budget 2011 announced that the fuel benefit charge multiplier for cars would increase by indexation to £18,800 in 2011.

Budget 2012 introduced a further rise from £18,800 to £20,200, and it will increase by 2 per cent above the RPI in 2013-14 before falling back to RPI in 2014-15. The Government also committed to pre-announcing the FBC multiplier one year in advance. The van FBC multiplier will be frozen at £550 in 2012 but will increase by the RPI in 2013-14. The 2014 budget confirmed that the car and multipliers would continue to rise in line with inflation in 2015-16.

Table 6 summarises the previous information. As with Table 5, these emissions are not produced using a single, consistent methodology so are not directly comparable.

Table 9: Emissions impact estimates of fiscal / regulatory measures
Project title Published emissions estimate
Air passenger duty -0.6MtCO2e in 2011-12 (UK)
Inclusion of aviation in EU ETS -183MtCO2e p.a. in 2020 (Europe)
Fuel Duty +0.5 MtCO2e p.a. by 2013 from two freezes (UK)
Reform of Vehicle Excise Duty40 -0.9 MtCO2e total savings by 2020 (UK)
Company car tax Not quantified
Fuel benefit charge Not quantified
RPP2 - Decarbonising Vehicles -2.5 MtCO2e in 2027
RPP2 - Sustainable Communities -0.3 MtCO2e in 2027
RPP2 - Business Transport Measures -0.5 MtCO2e in 2027
RPP2 - Network Efficiencies <-0.1MtCO2e in 2027
RPP2 - Additional Measures -0.75 MtCO2e in 2027

The emission estimates within this table are forecast increases or decreases in carbon dioxide emissions with the policy compared to without the policy in a given future assessment year. These estimates have been calculated using a variety of methodologies and, consequently, it is not statistically valid to aggregate the individual figures or directly compare them with one another.

3.4 Projected net emissions impact from Scottish projects

The Carbon Account for Transport collates information from a variety of sources and outputs with one of the key sources being the findings generated from the application of the Scottish Transport Appraisal Guidance (STAG) to transport proposals. Two key concepts in STAG are:

  • It should be applied proportionately but comprehensively. The whole process should be used and the level of detail required will be determined by the scale of the impacts of the transport issue being addressed.
  • It does not prioritise between options. Instead, it is an aid to decision makers to allow them to make informed choices. STAG may provide an initial rationale for investment and it is important that the STAG outcomes are revisited as the Business Case for an intervention develops.

As such, a study undertaken using STAG is not required to provide an absolute prediction of all of the outcomes of an intervention. Instead, it provides sufficient information to understand the relative impacts between different options. As such the results in Table 5 cannot simply be summed to produce an aggregate impact.

While these assessments provide one of the key purposes of the CAT - to improve transparency - something further is needed to monitor progress towards the NTS strategic outcome of reduced transport emissions. In 2010 a single model run of the Land-Use and Transport Integration in Scotland (LATIS) service was commissioned to estimate the net impact of all measures within the CAT that fall under the competence of the Scottish Government or other Scottish public body41. LATIS includes a strategic transport and land-use model covering all of Scotland and all motorised modes of transport so the use of LATIS to assess the carbon impacts of Scottish transport schemes ensures network consistency and takes full account of the potential displacement of developments between one area and another. The modelling of this set of projects over the timescale of their introductions also provides a greater understanding of the full impact that Scottish interventions are having, or are expected to have, on underlying emissions from transport. The model is not though a complete assessment of the likely impact as it does not include the impact of those measures taken at a reserved level, for example changes to fuel duty and some of the demand side measures outlined in RPP2.

A recent updating of the baseline data within LATIS has enabled a revised set of projections to be run 'with' and 'without' the CAT specific projects. The latest estimates from are shown in Table 10. The table shows that the combined impact of the projects is to generate a small increase in overall emissions, with the long-run impact estimated at an estimated additional 50 ktCO2e p.a. by 2027. The impact of these schemes is thus to add around a 0.4% to annual transport emissions in 2027 relative to where they would otherwise have been.

Table 10: Projected net emissions impact of Scottish projects42
Year Annual Change in Emissions (ktCO2e)
2017 30
2022 50
2027 50

This estimated increase in emissions is largely driven by a net increase in car vehicle emissions.