Written evidence from the Local Government Technical Advisers Group (SRN 018)

1. Introduction/ preamble

1.1                        Thank you for the opportunity to raise issues and submit evidence to this Inquiry. As a background we should add that we have written to the Secretary of State, Ministers and staff of the DfT on 29th August and did forward a copy of our letter to the Committee on 13th September.  Having consulted with Stuart McIlvenny he has advised us it would be easier if we incorporated the main points of our 29th August submission to Government in our evidence to you.

1.2                        We have received a reply from Jessica Hunt of the DfT on 8th October which did not really answer our fundamental points (copy of response from DfT provided as Appendix 1). The letter did not address the need for joined up policy, demonstrated the still very low level of maintenance funding for the 98% of the road network and the lack of recognition that road building wouldn’t solve congestion problems. It recognised that local authorities do generally understand better the local transport issues; however pronouncements by government on parking and traffic enforcement and control by the DfT and DCLG of minutiae seem to contradict this.

1.3              In our evidence to the Committee we have structured our response, following this Introduction and a Summary Issues section with a general analysis of the contents of the ‘Action for Roads’ document published in July making reference to the ‘Investing in Britain’s Future’ document published by the Treasury in June. This is covered in 3 sections:

• General Strategic Transport and Road issues
• Road Maintenance
• Organisational changes

Followed by responses to the six questions raised in the Call for Evidence.

1.4              The Local Government Technical Advisers Group (TAG) represents a large number of local authorities in the country, these include those with highway and transport responsibilities; such as Transport for London, most London boroughs, Metropolitan authorities, Unitary authorities, consultants providing highway and transport services for major local authorities and many of the districts and towns in two tier authorities. While these ‘second tier’ authorities do not have direct responsibility for transport, they do have a major role in looking after significant towns and the sensible overall planning of them including providing a reasonable environment and trying to ensure, through the Highways and Transport Authorities, that the transport system is fit for purpose. Overall we represent over 100 different authorities. Thus for any technical or professional group, we believe we are the most effective representative organisation likely to have a technical as well as public view on any policy issues (we are professional advisers to the LGA).

2. Summary points

2.1                        TAG does support and welcome the government’s views that we need to provide good transport and communications for people and the economy and we need to repair and renew considerable parts of our infrastructure.  However we have grave reservations on some of the assertions included and indeed on the strategy, spending plans and possible future administrative structures.

2.2                        We are particularly concerned that lack of clarity relating to the future of local highway authority roads will continue to increase the division between the 2% of the network under the management of the Highways Agency and the remaining 98% managed by Local Authorities rather than delivering the necessary integration. It should be noted particularly that for all practical purposes all journeys by whatever mode begin and end on the 98% of the road network that is managed by LAs. It is the journeys made by the customer road users that are important to the economy not just the roads classified as Trunk roads.

2.3                        While it may be a common perception that providing additional capacity would reduce congestion and help the economy there is little evidence to this effect. Furthermore for big cities it can often be the case that adding to the road network can make all travel worse. While this may be difficult to understand there is a wealth of published information which supports this fact. (We have provided some summary text, references, links and published documents that clearly support this – please see Appendix 2).

3. General Strategic Transport and Road issues

3.1              Where communications can be achieved electronically and physical transport can be avoided, this should be supported by Central and Local Government, individuals, industry and commerce - enhancing electronic communications, Broadband, 4G etc. is in everybody’s interests. The growth in electronic communications provides for easier home working etc.  and is likely to be a significant and growing contributory factor in the arrest of actual traffic growth, as seen in the last decade.

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3.2              Any person or freight movement is dependent on the use of the nearly 98% of the total road network that is Local Authority controlled - by car, delivery vehicle, bus, foot or cycle, at the beginning and end of each and every journey.  Although it has been stated that about a third of vehicle miles are on the Trunk Roads it is really the number of overall trips that are most important.  Furthermore it is certainly desirable that all Transport and Highway authorities encourage the minimisation of the travel distance needed to meet the needs of individuals or the economy as a whole - packing Kent potatoes in Somerset, or driving 5 miles to an out of town supermarket for a convenience shop, does not really help the economy – policies for transport should not encourage these all too real situations.

3.3              It is notable that Local Authorities have indeed managed to arrest traffic growth in many major urban areas and some smaller historic towns by effective transport and planning policies.  This has been very hard work and sometimes expensive with the constraints of the 1985 Transport Act outside London and often with less than full support by Central Government on issues such as management of parking and enforcement of moving vehicle offences. Furthermore increased capacity particularly of Motorways by the HA close to urban areas generates extra car commuting traffic which again contributes to Local Authorities difficulties in managing their networks effectively.

3.4              It is however welcomed that DfT circular 02/2013 (The Strategic Road Network and the delivery of Sustainable Transport) does suggest that trip generation should be minimised at source and sustainable modes of transport should be maximised and journey lengths minimised.  (para 12). It would be highly desirable if such an objective was carried through in government planning guidance for all developments and for the management and development of the Trunk Road network itself.

3.5              In both the ‘Investing in Britain’s Future’ and ‘Action for Roads’ document the impression is given that a road building strategy will reduce congestion in the future but it appears even from the Traffic Forecasts by the DfT that this is far from the truth and indeed the traffic congestion is predicted to get worse even with such major expenditure on the Trunk Road Network. This calls into question the need for alternative strategies and spending plans to deliver a different outcome nationally.

3.6              The conclusions of the Eddington review into Transport were that the major problems were in urban areas rather than interurban and there was an urgent need for policies to reduce traffic volumes. The statement in the Forward by the Chancellor and Chief Secretary - “It’s been the result of a collective national mindset that has privileged the short term over the long term, and has postponed difficult decisions” could not be more true especially if such a roads expansion policy rather than managing our total traffic is followed. (We should add that from the tenor of the statements made by Government that they mistakenly think that a road enlargement policy is what is needed rather than managing our total traffic). It is also particularly notable that the map of the most serious congestion even on HA roads (page 15 of Action for Roads) clearly shows the worst congestion close to the largest urban areas.

3.7              Funding and consequentially the management of local highway authority roads and transport services continue to remain uncertain, raising the concern of an increasing division between the strategic road network and the communities they purport to serve. Levels of capital funding are indicated to increase for local highway authority roads, despite questions relating to the overall affordability, but certainty of funding with the corresponding benefit of establishing a pipeline are receding, at least for the foreseeable future.

3.8              Capital funding is increasingly being provided as either relatively small one-off grants following competition or indirectly through organisations without responsibility for the network. However, the greatest concern relates to revenue funding which continues to reduce; revenue reductions are directly impacting on the ability of authorities to manage transport in their areas with the consequential and inevitable outcome that congestion will increase and ultimately safety decline. The revenue reductions are impacting on all aspects of transport infrastructure; bus services are being reduced, support for sustainable travel is being removed and road safety initiatives cut back.

3.9              The fixation on pot holes is in some respects welcome in that it is focussing attention in the deterioration of the fabric of the network but can detract from the argument relating to other essential aspects such as traffic signal maintenance, drainage and road markings, all of which combine to deliver an effective, efficient and safe network. Bland statements regarding these issues being the responsibility of local authorities to determine priorities within their budgets are at best unhelpful and ignore the root causes of the problem.

3.10              A somewhat separate but worryingly aspect of recent cuts in government funding has been the severity of the loss of skills from the sector. This reduction is greater and more severe than those of the 1980’s. The potential pipeline for major strategic road network could offer a glimmer of hope in terms of skills development and retention for the future, but only impacts on one area of the sector leaving other key areas with potentially greater uncertainty including transport planning, road safety, sustainable transport and highway maintenance. A clearer and more balanced view for the longer term investment in the whole local transport network is required.

4. Road Maintenance

4.1              We welcome unreservedly the long overdue extra expenditure for maintenance. We would however again stress that to improve the quality of road journeys for freight, cars, pedestrians and cyclists, the condition of urban roads and indeed rural non trunk roads need a vast improvement. We would be concerned if funding is skewed to the 2% of the road network rather than the 98%.

4.2              We note on page 5 of Investing in Britain’s Future, it is stated that “The Government has consistently prioritised capital investment over day-to-day spending” and consequentially the primary benefit of the additional funding will be to offset reductions in revenue budgets. However, this will not address the longer-term deterioration in the overall transport network, maintenance of key assets including traffic signals, drainage and road markings is being required to be reduced.

5. Organisational changes

5.1              We are concerned regarding any further reduction of public and democratic control of many of our busiest interurban and urban fringe roads by making the Highways Agency a more arms length organisation.  The Trunk roads must be considered as part of the overall road network and indeed part of the wider Transport Network.

5.2              Accountability of the HA in the new model raises concerns, it is a long held view that the HA and indeed DfT should be more directly accountable to the communities they effect by their decisions. However, there is a danger under new models whereby the HA could have greater freedoms and flexibility that it becomes more remote from the wider public, not just road users. Greater clarity might only be provided in terms of financial accountability.

5.3              The ability of the HA to invest outside the strategic road network is welcomed allowing a degree of integration but is a poor substitute for the provision of adequate funding to the local authorities to address problems in their areas. The framework for the HA must therefore include the ability and encouragement to invest in public transport, pedestrian and cycle  improvements, local access provision close to HA roads, Smarter Travel/ Travel Planning initiatives, Park and Ride etc.

5.4              A performance specification is all very well in principle but one thing we have learned is that in times of significant change, outcomes become more difficult to predict, particularly in the longer-term. If say journey time reliability is used as a key performance measure for the Trunk Roads, it can be improved by diverting traffic onto the local highway network, providing a perverse outcome.  Such an outcome may be acceptable to the users of the 2% of the network but would be highly unpopular with local communities who would potentially be left with no direct recourse to the HA and local authorities powerless to intervene.

5.5              Regarding the identified management models each would seem to have potential drawbacks. The formal contractual model appears fraught with difficulties associated with performance increasing in complexity with duration of the contract.  The regulated utility model appears least appropriate given their performance and lack of alignment with broader national economic requirements; for example reduced energy prices with more modest profit margins would be in the public interest. The trust model addresses an issue of concern relating to the balance of service provision and profit but leaves the question of performance unanswered and previous statements appear to have ruled out the transfer of the assets.

5.6              Freeing the HA from the constraints of short–term funding and restrictive employment processes is welcomed but these issues are also faced by Local Authorities managing the rest of the network.  Furthermore at this stage there appears to be no clarity regarding how funding for the new model will be resourced.  It is to be hoped that new HA company would not run up large deficits, off book for government, as Network Rail has, as this really represents hidden public debt.

5.7              The benefits of longer-term financial planning and certainty for the HA are welcomed and should secure greater commitment to workforce training in apprenticeships and also importantly higher technical skills.  However, a critical shortage of skilled staff is inevitable given the rapid shrinkage we have suffered and without such commitments will not be remedied, although given the uncertainties in the wider public sector funding, skill shortages are likely to remain in the long-term.

6. Answers to specific questions raised by the Transport Committee

How will the policies set out in the Government’s “Action for Roads” command paper improve the strategic road network for all road users, whilst also improving the environment?

6.1              The proposals identified in Action for Roads could deliver greater and longer-term certainty in terms of the performance and delivery of improvements on 2% of the road network (if delivery of (capacity) improvements are really required). However the presumption that congestion can be tackled by increased capacity and demand for growth satisfied is not backed by evidence.

6.2              There is evidence that a number of local authorities have been successfully managing congestion with growth in their local economies and without the need for increases in overall road capacity. The key principle adopted being that of the integration of policy and investment programs across modes with a specific objective of sustainable growth. Greater emphasis is required regarding the coordination of investment and in particularly in terms of the working with local authorities to ensure that the economic growth is sustainable.

6.3              The lack of clarity regarding the direction of funding for local transport raises significant concern whether sustainable growth can be achieved. Funding is being reduced both in terms of capital expenditure (local authority capital transport spend has reduced by almost 25% in the last two years) and also in terms of revenue spend including reductions in funding for maintenance and operation of public transport (concessionary bus fare funding for some authorities alone is facing a potential reduction of 35%). Government needs to “join up” its thinking regarding transport and cannot blindly assume that increased investment in the Strategic Road Network alone will result in better transport outcomes.

6.4              The barrier posed by the trunk road network to cyclists and walkers, particularly on the edges of urban areas is understated and the vague assumption that the movements can be accommodated on local networks an overstated simplification. In many instances key links between communities have been severed and significant investment is required if these barriers to efficient and sustainable movement are to be removed. A clearer commitment to supporting such improvements to provide key links which may well be on local networks, is required.

6.5              Investment in new technology and support for alternative fuels is welcome, however without better integration of policy and investment across modes and networks there is a danger that even the environmental cost, of trying to achieve growth by trunk road enlargement will be significant.

How does the Government’s policy for roads link with planning for other transport modes?

6.6              In part this is covered in the response and section 3 above and there is great concern that the outcomes may not be desirable particularly in terms of both commuter and longer distance journeys.

6.7              One potential outcome, is that additional capacity provided in the strategic road network will result in the transfer of trips from public transport and longer journeys for goods and people. If this is to be avoided coordination in terms of policy development and delivery need to be integrated.

How reliable is the Government’s forecast for growth in demand for the strategic road network? How should the Government deal with uncertainty in its forecast? 

6.8              Forecasts provide potential indications of outcomes; the fundamental assumption that high growth in the economy must result in higher levels of traffic needs to be challenged and highest traffic levels should be considered a failure of transport policy rather than successful economic policy. It is notable that even in London the DfT is predicting traffic increases however London has grown substantially in population terms and economic performance over the last 20 years without road traffic increases.

How can we improve the reliability and efficiency of travel on the strategic road network? What impact will new technology have?

6.9              Reducing the total amount of (particularly car) traffic on the network by  promoting public transport and other more sustainable modes of transport, support local planning authorities to ensure that all new development is located and designed for sustainable transport, provide better and timely information to enable users to make choices regarding modes and times of journeys. Support companies and individuals in sustainable travel options.  Invest in electronic communications to avoid the need for some travel.

6.10              While there may be scope in the future to increase the capacity of the strategic road network by electronic measures these will not be available in the foreseeable future for most of the 98% of the network so unlikely to be effective for improvement of reliability of journeys even if such measures did not increase traffic levels.

6.11              Variable speed limits more electronic enforcement and better identification and more reliable information to drivers and traffic control managers could help reduce incidents and accidents causing congestion.

What mechanisms are there for Government to increase investment in strategic roads and attract new investors? Are there good examples from other countries that could be applied in the UK?

6.12              We have previously given verbal evidence in answer to a question by the Committee that we considered that generally there was an adequate strategic road network in the country nevertheless its management, integration with national and local transport strategies and maintenance could be improved.

6.13              To attract investment there must be a revenue stream available. TAG are on record as supporting congestion charging/ road user charging as is done in many countries throughout the world to fund maintenance of the strategic road network.  We do not believe that such charging should be for isolated links but managed as part of an overall transport strategy.  We also recognise the political difficulties in the introduction of charging regimes, nevertheless they are generally supported by industry to reduce congestion and help the economy.

How should the Highways Agency be reformed to make it “the world’s leading highway operator”? What roles should Government and the private sector play to ensure better management of the strategic road network?

6.14              The first step in improving the Highways Agency is to ensure that it does not exist in isolation and needs to be based on a sound integrated transport policy and treat as a whole network involving LAs.

We hope that this evidence will be useful to the Committee. We would be pleased to elaborate, provide any supporting evidence by additional documentation and verbally in front of the Committee.

October 2013

Supporting documents:

Appendix 1 – 8th October response from DfT to TAG 29th August 2013 letter

Appendix 2 – Summary, links and published reports on road building induced traffic and congestion

Appendix 1 to TAG evidence to HOCTC Strategic Roads Inquiry
 

Dear Martin Sachs,

Action for Roads

Thank you for your response to the ‘Action for Roads’ command paper, we take on board your concerns about the lack of clarity relating to the future of local highway authority roads. This paper focuses on the strategic road network as funding for local roads is now devolved to local authorities, who know their own network better than any national body or outside observer, and they remain the people best placed to manage their assets.

The Government is committed to ensuring that UK transport infrastructure supports economic growth, and this of course depends on effective interfaces between networks. It is therefore important to ensure that the network which the government controls operates as effectively as possible and why we will be implementing reforms to drive efficiency and transform its current operation.

Our forecasts indicate that traffic levels on strategic roads will be 24% higher in 2040 than they are today, in our central case traffic will rise by 46% above today’s levels. This why the investment announced at the Spending Round is absolutely essential to ensure our national network, which has been all too susceptible to underinvestment, is fit for the 21st century, will support economic growth, and allow the UK to keep pace with our international competitors.

Reforming the Highways Agency into a publicly owned company, with an investment strategy, and road user watchdog, represents a clear break from the short-term thinking and stop-start culture that has affected the management of the network to date. The Government’s proposed reforms will put in place the structures, commitments and relationships to support a more ambitious infrastructure programme, and allow the strategic road network to operate more like the best-performing infrastructure providers in other sectors. This will have knock on benefits for suppliers. Credible independence will allow confidence in road investment plans, enabling suppliers to procure materials at lower costs through longer contracts and invest more in recruitment and staff training.

We are conscious of the importance of embedding strong safeguards within the new organisation to ensure that the strategic highways company continues to deliver its obligations. We will shortly be publishing a consultation providing further detail of our plans to reform the Highways Agency

We are also clear to put in place measures and a framework to ensure that the network operates effectively as part of a wider transport system. In May 2012 we set out a new way to plan the management and enhancement of our road network to take account of local needs and interests, via route based strategies (RBS). This process has been designed to bring together different interested groups – local authorities, Local Enterprise Partnerships, motorists’ organisations, environmental groups and others – to discuss the future of a section of the strategic road network.

In the next two years RBS’ will cover all of the network and will heavily influence the development of the Road Investment Strategy, building an investment framework that recognises that in some cases the best way to address capacity issues on the SRN will be to do something off it – for example the funding the Manchester Airport Eastern Link Road (MAELR) to allow local traffic to stay off a nearby stretch of the M60.  This will also enable the strategic highways company to target investment in the network that will benefit of the surrounding areas, as was the case in connecting the A453 to park and ride facilities at the Nottingham Express Transit to reduce traffic in town centres.

As you note in your letter, the government is committed to investing in maintenance for both local and national roads. In the Spending Round in June earlier this year, the government committed £12 billion for road maintenance to 2021, £6 billion of which is dedicated to local roads. This represents the biggest sustained commitment to maintaining our network in decades, and will decisively make up for the underinvestment of the past twenty years.

The department is also due to publish a National Policy Statement at the end of the year which will set out the policy and planning framework within which applications for planning consent for road, rail and rail freight interchange developments over a certain size are considered.  The purpose of the NPS is to provide clarity and certainty on Government policy for promoters (HA, Network Rail, developers), the planning inspectorate (PINS) and decision makers (Ministers). It will make an important contribution to removing planning barriers to growth by providing clarity to applicants and decision-makers on the government’s priorities for development of the networks and the criteria against which developments will be assessed.

We agree with the point you make in your letter, regarding the need to consider a variety of measures to address capacity issues. User information is becoming an increasingly valuable tool in effectively managing the network. We discuss this in detail in Action for Roads, and as you highlight we will continue to look at new ways to address capacity issues on our road network through better information.

Similarly, the government is committed to relieving freight traffic on our roads. The Department for Transport currently provides freight grants to industry to encourage modal shift from road to rail or water, where the cost of using rail or water are higher than road; and where there are environmental benefits to be gained. Two freight grant schemes help to remove over 800,000 lorry journeys from Britain’s roads annually.

With regards to remote working, such practices are not for government to dictate but for individual businesses to consider depending on their own requirements, network capabilities and spending decisions. However, Government does have a role in promoting choice and raising awareness amongst businesses and individuals of the different options and many benefits of the alternatives. The Department has therefore commissioned work to explore how widespread alternatives to travel could potentially benefit the UK, looking at resulting travel patterns, and the impacts on travel demand to determine how the impacts of home working feed into the transport system.

Yours sincerely,

Jessica Hunt

Appendix 2 to TAG evidence to HOCTC Strategic Roads Inquiry

Summary, links and published reports on road building induced traffic and congestion

There is very strong evidence (but not as widely known as it should be) that road building can increase traffic levels enormously; although the mechanisms – mode change, redistribution, peak narrowing, genuine new trips etc  resulting in the extra traffic is less clear.

Congestion at the end of the new roads and elsewhere from the extra traffic, although very visible, is much harder to quantify properly. 

The December 1994 SACTRA report ‘Trunk Roads and the Generation of Traffic’ is probably the most robust evidence and analysis of all this.  The SACTRA work itself pulled on a number of different evidence sources - not only the before-and-after traffic counts but also inferences from large numbers of studies of values of time, demand elasticities, differential growth rates, and surveys. It was because all these told a broadly consistent story that SACTRA felt able to be more decisive in its conclusions than the DTp was expecting at the time.

Since then there has been one completely different type of evidence base as well: this is the complementary literature on traffic reduction following road space reductions (pedestrianisation, bus lanes, disasters, maintenance closures, etc). This is important in its own right, but also significant in giving confidence that the induced traffic effect is not an artefact due to economic growth or similar. The largest empirical compilation is a book Cairns S, Hass-Klau C and Goodwin P (1998) Traffic Effect of Highway Capacity Reductions, Landor Publishing, London, with some updating papers subsequently of which one was awarded a gold medal by the Institution of Civil Engineers.

SACTRA does show that the net effect of road enlargements could actually create more congestion.  Mogridge and Thompson really propounded this in their various books and papers and it certainly can apply most in big cities on radial routes.  Explained simply there is a vicious circle --- more road space – more car use -  less public transport use – fares go up, frequency goes down – more people transfer to cars etc and the new equilibrium point is a lower level of service in both cars and Public Transport.

 Apart from SACTRA there is:

• John Elliott’s 1985/6 original work with colleagues at GLC which was republished in WTPP (http://www.johnelliottconsultancy.co.uk/wtpp05.2.pdf  see editorial and pages following 28. (this work was also part of a submission by John Elliott and Derek Turner in 1987/8 to the House of Commons Transport Committee on behalf of ALBES (the precursor to LoTAG)
• A report done for CPRE and others in July 2006 (available)
• An article by Phil Goodwin in August 2006 published in LTT with the editor’s comment "(Don't lose this - we might need to publish it again in 2014 - ed)" (attached below)
• A paper presented by John Elliott and an Australian academic (Dr Michelle Zeibots) with a version very recently  published in WTPP (http://www.eco-logica.co.uk/pdf/wtpp17.3.pdf).
• Evidence from the M25 and other roads that is clearly visible to anybody - When the western arm of the M25 was widened from 3 to 4 lanes it was reported that traffic increased by 33% in a year (exactly the same as the capacity increase!).  A similar experience occurred with hard shoulder running on the M42. 

It is interesting to note that SACTRA came out during a Conservative Government and Transport Minister Stephen Norris said at the time that the government would not have built so many roads if they had known about it.

While this gives robust evidence of roads generating traffic there is also substantial evidence that extra roadspace and higher speeds do not necessarily provide economic benefits. Reference can also be made to the 1998 SACTRA report on roads and economic regeneration which included doubts that the economic benefits could be as high as the calculated time savings. We also know that the ‘economic benefits’ calculated largely on basis of predicted time savings are highly artificial.

It appears that the statements of certain business people and the roads lobby is being used to make the case for Trunk road improvements rather than any evidence.  It is an easy message to say that widening a road would appear to be a solution to congestion! The real message on transport policy is much more complicated.

Phil Goodwin’s article in LTT

Induced traffic again. And again. And again.

Phil Goodwin

When the costs of travel are reduced, people do more of it. When the costs of car travel are reduced, people use cars more. Why are these obvious propositions so forgettable that they need to be proved anew every decade?

It was way back in 1925 that the opening of a new section on the Great West Road demonstrated 'the remarkable manner in which new roads generate new traffic', as Bressey wrote in 1937.  Soon forgotten. Glanville and Smeed at the Road Research Laboratory rediscovered it in 1958, and Foster, at Oxford, in 1963, and it was remembered long enough to appear in Ministry of Transport advice in 1968, which said:

"Generated traffic on large schemes has often amounted to between 5% and 25% over and above the normal forecast traffic level…larger in exceptional cases"

Within three years the advice disappeared (nobody ever said why), and generated traffic was routinely not calculated for road schemes. The DoT took a legal case to the House of Lords to prevent such forecasts being challenged by objectors. But the evidence kept re-appearing: a GLC study demonstrated it empirically in 1985, as did Martin Mogridge and his colleagues in 1987, and it was sharply reinforced in 1988 after the M25 exceeded its long term forecast traffic growth within months of opening.

In 1994 SACTRA, the Standing Advisory Committee on Trunk Road Assessment, published its best known report, on what it renamed 'induced' traffic. The average traffic flow on 151 improved roads was 10.4% higher than forecasts which omitted induced traffic, and  16.4% higher than forecast on 85 alternative routes that improvements had been intended to relieve. In a dozen more detailed case studies the measured increase in traffic ranged from 9% to 44% in the short run, and 20% to 178% in the longer run.  This fitted in with other evidence on elasticities, and aggregate data. The conclusion was

"an average road improvement, for which traffic growth due to all other factors is forecast correctly, will see an additional [ie induced] 10% of base traffic in the short term and 20% in the long term"

The Department of Transport accepted this. The report was updated it in a special issue of 'Transportation' in 1996 (including my own review, as lead author of the 'evidence' chapters of the SACTRA report).  Bob Noland and others for the USA, and many authors in Europe, have since demonstrated similar international results.

Fast forward to July this year. CPRE published a report by Lilli Matson, Lynn Sloman, Ian Taylor, and John Elliott. The authors were known to me - I worked with Lilli on the Ten Year Plan for Transport, with a report we called 'Running to Stand Still'; with Lynn on 'Smarter Choices', and also the West Midlands TIF programme; and with John (who did the original 1985 GLC study, with Jill Beardwood and Steve Purnell) on the Thames Gateway Bridge.  They are a serious group of engaged professionals, and I opened their report with interest.

It's called 'Beyond Transport Infrastructure', and what they have done is look in detail at three big schemes on the A27, A34 and M65, and a further ten schemes on the A5, A6, A41, A43, A46, A66, A500 and A1033. These were schemes undertaken after SACTRA's 1994 report had been finished and accepted. They reported:

"Careful scrutiny of the traffic flow data suggests that traffic growth after the scheme opened has been significantly higher than growth on other nearby road corridors or national traffic growth"

"…in all three case studies the current traffic flows are near or already in excess of what was predicted for 2010. In towns with bypasses, such as Newbury and Polegate, the new roads did significantly reduce the town centre traffic levels. However, these reductions are not as great as originally forecast and there has subsequently been regrowth in traffic levels on the bypassed roads. The net effect in combination with the new road is generally a considerable overall increase in traffic".

Their final conclusion is remarkably restrained. After noting the Highways Agency's own explanations for the extra traffic growth, (which were intriguingly similar to those rejected by SACTRA 12 years earlier), they write

"Nevertheless, in view of the fact that many of the schemes reviewed have demonstrated significant increases in traffic volumes (in the range of 10-35%, within a period of one to two years after opening), there would seem a strong case to consider the issue of induced traffic in more detail in future evaluations".

So 1925, 1937, 1958, 1963, 1968, 1985, 1987, 1988, 1994, 1996, now 2006: for eighty years, every eight years on average there has been the same experience, the same conclusions - even, for goodness sake, more or less the same figures. The evidence has been consistent,  recurrent, unchallenged by serious countervailing evidence, but repeatedly forgotten. CPRE have done us a service, I think, but really it should just not have been possible for them to find, 12 years after SACTRA, the same mistakes.

There may well be situations when it is justified to encourage more traffic, but this should be done cautiously, with eyes wide open about the implications, not by denial. Induced traffic tends to increase environmental damage, and usually tends to reduce the calculated benefit-cost ratio of a road improvement, because the period of relief from congestion will be shorter than planned; also because the benefit to the marginal extra travellers is less; and because assuming the extra traffic is not induced artificially makes the 'without' case worse than it really would be. It is a bit more complicated to predict.

Maybe that's the problem. The methods you can use if there is no induced traffic are cheaper, and have the incidental side effect of uplifting the calculated benefit. If the promoter of a scheme is the same agency as is responsible for its appraisal, that's two quite big incentives to get it wrong, and no countervailing pressure to get it right. Except, perhaps, the embarrassment of the next research study? But that will be nearly a decade later, and somebody else's problem.