Taxation of road users
The solution to the problem of externalities is often the imposition of an indirect tax. This is shown below
The tax imposed raises the market price of transport to 0P* from 0P1 the price charged without intervention. As MSC = MSB at this new level of output (0Q*) the allocation of resources is allocatively efficient. This is known as internalizing the externality - the full social cost is now reflected in the price paid by the consumer.
There are two main problem:
Estimating the social costs and benefits involved.
Differentiating between the road users that cause externalities.
In 1999 road users paid £26bn more in tax than was spent on roads. This represents a cost, as stated earlier, of 5.4p per vehicle km. According to Mumford’s figures an HGV driving through an urban centre at peak times imposes 87p of external costs on society for each km traveled, but a private car traveling in rural areas imposes just 0.8p of external costs. Thus a single tax policy will fail to reduce the demand sufficiently in urban areas and will penalise those who live in rural areas.
Who pays for the infrastructure?
This is known as the track costs argument. Confusingly it is applied to roads not rail, but is concerned with who pays for and who benefits from the provision of roads. In the case of railways it is fairly easy to see who should pay for the provision of track, but who should pay for the roads and their maintenance.
The track costs are;
Construction costs
Maintenance costs
The payments made are in the form of;
Fuel tax
Car tax (on new cars)
Vehicle excise duty (the Road fund licence)
Value added tax
Originally the road fund licence was seen as a fund from which road network improvements could be financed. In the technical jargon it was hypothecated for road building and ongoing maintenance. The link is no longer made.
Cars and light vehicles paid 3.7 times more in tax than the track costs associated with them in 1994/95. Heavy goods vehicles paid only 1.4 times more than the costs due to them.
Due to externalities it is argued than private cars should pay more (even more) to use the roads, but that as heavy goods vehicles are production related they should pay less, i.e. just their track costs.
Public transport reduces the level of negative externality and so should be encouraged with lower taxes or even subsidies.
The recent rise in the excise duty on fuel has led to widespread objections from the road haulage industry which has included protests on the roads around London. This reflects how difficult it is politically to deal with the problems of transport. As Table 9 in Bamford shows HGV’s pay a proportionately lower amount in tax than private cars compared to track costs.
Pricing transport services
As we have seen there are a considerable number of sources of external costs in transport. This makes the pricing of all transport services difficult.
The main problem is that the user has no idea of the full social costs of a journey. However for private transport the private cost of a journey is often not apparent either.
Consider the following situation:
A couple are going from London to Birmingham for the weekend, a journey of 115 miles. In 1992 the train fare (cheapest possible) is £23 each (£46 in total) while the cost of taking the car is £11 of petrol (remember 1992 prices).
The train fare includes a contribution to the fixed costs of the railway while the petrol cost is only the variable cost of the car journey. When the cost of car servicing, depreciation and a contribution towards insurance are included the cost of the journey based on average mileage and a Peugeot 205 is £41.
The user of the car will be unlikely to look at the cost of the journey in this way. To them the annual running costs of the car are given, even though they do vary with milage. A rise in the cost of petrol to £16 would make it just as expensive to drive, but it is very unlikely that many drivers would decide to take the train as it is much more difficult to do so (fixed departure times and getting to and from stations rather than going door to door).
Price discrimination
In the area of public transport there are considerable economies of scale to be gained. This is largely due to the existence of constantly falling cost curves in the rail industry. Efficient pricing in the sense of allocative efficiency (Marginal cost = price) is, therefore, impossible. In the bus and rail industry there are many empty seats at off peak times and filling these seats, increasing the load factor, will lead to lower costs per passenger km. In freight the same argument applies, raise the load factor and reap economies of scale by reducing the cost per tonne km.
Price discrimination has been used to solve this problem. This is a situation where a firm charges different prices to different groups of consumers for identical units of supply. It is based on a principle of charging ‘what the market will bear’ and relates to differing levels of elasticity.
Constantly falling cost curves
The diagram shows the difficulty faced by an industry with a natural monopoly. If more than one firm operates in the market then the demand curve shifts to the left of ATC, making it impossible to charge a price that covers costs. If the demand curve lies to the right of ATC for any distance then it is possible to price to make a profit, but not where Price = marginal cost. At the output 0Q1 if price is set at marginal cost a loss of C1C2ab is made.
A monopolist could charge 0P1 for output 0Q1 and make a profit.
The transport market is not always that simple. British Rail find that due to competition on some routes and in some markets they face widely different elasticities of demand for train use. Also covering costs is not as simple as in the diagram above (i.e. the demand curve lies closer to the ATC curve).
The solution to the problem is to discriminate between customers to allow the overall service to make a profit when charging one price would not.
The price elasticity of demand for some rail services is highly inelastic, for example business travel to London and commuting to major cities. This is because there is little competition from other forms of transport (such as cars). It is possible to charge high prices on these routes.
The market for travel for holidays and visits is much more competitive. Time of travel is not so important and so cars and coaches provide stronger competition. The price elasticity of demand in these market segments is elastic. It is necessary to offer lower fares in these markets, and so raise the capacity utilization of the service.
Due to the nature of the cost curves any contribution above marginal cost adds to profit. Thus given the high revenues form business passengers the railways can offer other travelers lower fares and still add to profits.
Rail companies adopt a twin approach. Discounted fares for everyone who was prepared to travel at off peak times and with certain restrictions (sometimes offering only a limited number of seats at the discount price) and discounts to certain groups, such as OAP’s and young people. These groups were believed to have high price elasticities of demand for rail travel due to low budgets and high competition.
Table 10 in Bamford illustrates a typical BR pricing policy on one route.
In addition to the discrimination within the standard class carriages of trains there is a first class section. While this offers a better service it is another use of different elasticities of demand between customers. The table below shows the volume and revenue percentages on the rail network in 1992. It shows that if the lower priced tickets were withdrawn there would probably be a significant drop in volume. As the trains will probably just run with fewer passengers this suggests only a small corresponding reduction in costs.
The transport market is not always that simple. British Rail find that due to competition on some routes and in some markets they face widely different elasticities of demand for train use. Also covering costs is not as simple as in the diagram above (i.e. the demand curve lies closer to the ATC curve).
The solution to the problem is to discriminate between customers to allow the overall service to make a profit when charging one price would not.
Subsidizing transport
Many passenger services are unable to bring the operator a commercial rate of return whatever pricing strategy is used, e.g. rural bus services.
Subsidizing the service can reduce the fares paid by passengers and raise the numbers using the service.
Subsidies can bring social benefits by;
reducing traffic congestion,
limiting harmful emissions,
reducing journey times and
improving the mobility of low income groups.
The total subsidy necessary to move the market to the socially optimal output of 0Q* is equal to ABCD. This allows the market price to fall from Pm to 0D at which consumers are prepared to purchase 0Q* units. Effectively the supply curve has been moved to the right, passing through point C.
As private transport imposes external costs and public transport has social benefits and reduces the negative externalities of private transport an economic policy that taxed private transport to subsidize public transport would move the economy towards a more efficient allocation of resources.
An alternative way of showing a subsidy is shown below.
Subsidies are little used in the UK, but transport is an exception. Transport subsidies are either targeted at certain groups. e.g. pensioners or the rural bus subsidy, or are swallowed up within national costs and not reflected greatly in lower fares, e.g. the subsidy paid to the rail franchise operators.
Local subsidies can have an effect, e.g. West Yorkshire where the Passenger Transport Authority subsidized the local rail network. In 1995 the average fare per passenger mile for journeys wholly within the West Yorkshire metropolitan area was 12.2p, for journeys not wholly within the area it was 16.7p.
Arguments for subsidies in passenger transport are:
Social equity - groups who could not otherwise afford to travel are able to do so.
Promote positive externalities - greater use of public transport in urban areas reduces traffic congestion.
Urban regeneration - Establishing a cheap, efficient public transport service to a run down area promotes growth, e.g. Manchester Metrolink, London Docklands.
Environmental protection - reduce pollution or damage in an area such as the world heritage city of Bath, where pollution from cars attacks the limestone buildings.
This could be achieved by subsidizing ‘Park and Ride’ schemes.
Arguments against subsidies in passenger transport are:
Blanket subsidies are indiscriminate - a general subsidy benefits all passengers regardless of income.
Subsidies breed inefficiency - if subsidies are offered managers come to rely on them and operating costs are higher than they need be.
The inefficiency argument has had significant impact on UK policy towards bus and railway subsidy.
How much subsidy?
A private firm will assess a transport service according to the financial viability of the service, what might be called a ‘cost revenue analysis’. As we have established the external costs and benefits of transport services means that this is not always going to lead to an optimal allocation of resources. However knowing this does not tell us which services to subsidise or by how much.
A cost-benefit analysis would allow us to judge if it was worth subsidising a service.
The reason for using CBA is because;
CBA takes a long view and a wide view.
The long view is needed because the infrastructure is in use for so long and the wide view because of the externalities.
Elements of CBA
Identification of all costs and benefits
Valuation of all costs and benefits
Assessment of risk and uncertainty in forecasting costs and benefits
Discounting future costs and benefits to find net present value
Compare alternative projects
An illustration of CBA to assess subsidy
Suppose a railway service is privately run and the owners are considering closing the loss making service. A cost revenue analysis would consider the following:
Private benefits of closure Private costs of closure
Capital replacement cost savings; Loss of train service revenue.
(Stations, track, bridges, signaling, Cost of alternative bus service.
rolling stock.)
Operating cost savings;
(Labour, fuel, maintenance.)
Resources transferred to other services.
Revenue from alternative bus service.
However the closure of the service will affect both users and non-users of the train service and a CBA must consider the effects on:
The existing users of buses and trains.
The existing users of other modes of transport, e.g. private car users and pedestrians.
The transport operators and the authorities providing roads.
The rest of the economy.
The following issues will arise:
Time savings on trains - the alternative trip will take longer.
The effect on feeder services - the loss of one service may reduce traffic on the rest of the network making it less viable.
Accident savings on roads - the closure of the railway implies higher road traffic volumes and so more accidents.
Overcrowding - on roads (congestion) and buses. More congestion means that existing road users have longer journey times and this implies a loss of welfare for them.
Time savings on road - the alternative trip may be shorter.
Journeys not made - some people will simply not undertake the journey anymore. This will mean a deadweight loss of welfare for those who used to use the service.
Employment impact - the loss of the service will lower railway employment, but may raise employment elsewhere. A local multiplier effect may be involved.
Environmental effects - e.g. more road use implies higher pollution.
We can add the following costs and benefits to the cost revenue sum to produce the full cost benefit analysis.
Social benefits of closure Social costs of closure
Benefits in journey times. Replacement costs on non-passenger (For former rail customers that spend services.
less time traveling and existing bus (Freight and parcels taken by road users who get an improved service.) transport.)
Connecting services. Journey time increases.
(Cost savings due to fewer connecting (Former rail users journeys taking longer.)
passengers.)
Journeys not made.
Environmental effects. (Loss of mobility by individuals)
(Lower noise, pollution for those living Increased car operating costs.
near railway.) (From journeys transferred to cars.)
Increased congestion costs.
(From increased passenger and freight traffic.)
Increased accident costs.
(From increased traffic flows.)
Additional road maintenance costs.
(Avoided by the retention of the rail service.)
Additional public transport resource costs.
(This cost relates to additional vehicles.) Loss of employment in local area.
(Multiplier effects.)
Environmental effects.
(Higher noise, pollution etc. from roads.)
The amount of subsidy a scheme receives should not exceed the net benefit of retaining the scheme. This ensures that society as a whole gains.
The main problem is that the funding of subsidies will often be limited by available cash and may be subject to political decision making also. There are probably more public transport services in need of subsidy than there are funds on the basis of performing a CBA.
Valuing time
One of the factors that has a great deal of impact on CBA’s of transport projects is the value of time. In the example of the bus and train routes above the value of time lost or gained by users was included. Often it is the value of time that is decisive.
There is an accepted formula for valuing time. Where time is gained the passengers gain consumer surplus. This is evaluated by the use of Department of Transport Manual which gives values for ‘in-vehicle time in non-working hours’. The DoT data is based on survey and behavioural study data that considered mainly journey-to-work trips and choices made by people between, for example, lengthy trips at a lower cost rather than shorter more expensive journeys. This is a form of shadow-pricing, putting a value on something where there is not an actual market, but it is priced as if there was.
In the case of journeys undertaken during working hours the value of travel time is based on the price paid for a persons labour.
Thus the value of time lost or gained is given by the appropriate value multiplied by the time lost or gained.
The table shows the values of in-work time for 1998.
£ per person per hour (1998)
Working time
Car driver 17.44
Car passenger 13.69
Bus passenger 11.09
Rail passenger 25.17
Underground passenger 21.15
Bus driver 6.68
All workers 11.57
Non-working time 4.52
(Source:Transport economic Note, DETR.)
The values here are ‘before the fact’ and reflect an estimate of the willingness to pay of the groups identified to avoid the time delay. Therefore the difference between, for example, a bus passenger and a train passenger, reflects income levels and the value they put on their time.
Another way to do this is to value the vehicle journey per hour. This is less accurate, but useful where data is not of sufficient quality to value as above. Examples of 2006 values were:
Type of vehicle Value of time per vehicle
and journey purpose (£ per hour)
Car – being used for work 24.99
Car – commuting 4.75
Car – other (i.e. leisure, shopping) 6.81
Goods vehicle 8.42
Bus/coach 59.16
Average all vehicles 9.30
Investment in transport13
The nature of transport investment
There are two types of transport investment
1. Infrastructure investment - new motorways, bypasses, light railways.
2. Purchase of vehicles.
Most infrastructure decisions are taken by government agencies (although many more are now taken by the private sector).
The private sector uses methods of investment appraisal that look at the rate of return on the investment. Because much of public sector infrastructure investment is in public goods where market prices do not exist special methods of appraisal must be used. (Private road investment is only 2% of total expenditure on road infrastructure.)
Recall that public goods have two special features;
Non-excludability - providing the good for one person means it is available for everyone else too.
Non-rivalry - the consumption of the good by one person does not prevent others from enjoying it also.
Some goods exhibit qualities of non-rivalry up to a point, e.g. a road, but when they reach capacity usage there is rivalry. Also some goods are restricted to certain groups, e.g. roads - only over 17’s with current licences may drive cars on them.
Bamford lists lighthouses as public goods. This is a well known example due to Samuelson, but as Mankiw pointed out that there used to be many privately owned lighthouses.
Investment in transport infrastructure has particular features.
1. It is long term in nature - usually lasting in excess of 30 years.
2. It involves a high capital outlay.
3. It generates both positive and negative externalities.
4. It represents an important part of local or central government capital spending.
Despite these features most transport infrastructure expenditure is made without direct charge to the user.
Thus the government must decide how much it spends on infrastructure and which projects it funds and which it does not. All projects are cash limited and there has not been a period when the budget of the department of transport has been sufficient to undertake more than a few of the possible capital projects. There is, therefore, a need to prioritize infrastructure projects.
Cost-benefit analysis (CBA) is used to decide the answers to these questions.
COBA method of appraising roads14
The Department of Transport use a computer based form of CBA known as COBA to evaluate new inter-urban road schemes (those between towns or cities). It compares the costs of a new road scheme to the benefits that will be derived by road users. In this sense it is more limited in scope than a full CBA.
Three types of benefit are recognized:
Journey time savings - based on the ‘time is money’ principle these usually turn out as the most important benefit. A monetary value is put on the aggregate time saved by users of the new network. The value depends upon the purpose of the trip e.g. work or leisure as shown on page 40. The method assumes that any time saved would be put to good use and that the value of output must at least be equal to earnings.
Vehicle operating cost savings - the new network will affect fuel consumption (usually higher) and wear and tear (usually lower). Such savings are particularly significant for commercial vehicle operators. Potentially fewer vehicles are required for the same amount of work.
Accident cost savings - motorways and trunk roads are safer than normal roads. The reduction in accidents is given a value based on the direct costs to individuals, their vehicles, the emergency services, lost output and an allowance for pain and grief following death or injury.
Two main costs are recognized:
Capital costs - land purchase, construction costs, admin and design.
Maintenance costs - street lighting, repairs and resurfacing.
All costs used are resource costs. This is because opportunity cost is the relevant economic cost for CBA. Although market prices largely reflect resource cost taxes and subsidies must be eliminated.
The standard period considered is 30 years into the future. The discount rate currently used by the DoT is 6%.
The NPV of the road tells us if it is of net benefit to society (a positive NPV). The ratio of benefits to costs is worked out. Thus if the Present Value of Benefits (PVB) is £40m and the Present Value of Costs (PVC) is £20m the NPV is £20 and the Benefit-Cost rato (BCR) is 2 (or 2:1). This ratio helps in prioritising schemes.
It is claimed that COBA has three practical purposes.
It establishes the need for a particular scheme.
It allows priorities to be established.
It provides the basis for wider discussion.
The choice is not always between the existing situation and the new road as the analysis above suggests. For example a traffic management scheme might be a possibility on the existing road network. If so then the comparison between the new road and the result of implementing the traffic management scheme is relevant. It is more complicated to do this, but if this does not happen it is possible the benefits attributed to the new road may in fact be really due to a cheaper alternative.
It is not possible to perform a full COBA on all possible projects. To avoid undue cost a ‘first sift’ of projects is done based on criteria such as work flows or number of residents on a particular road.
Given the limited funds available demands for new roads exceed the resources available, therefore some method of appraisal is essential. COBA is not perfect however.
Complications of COBA method
Much of the data for COBA estimates are forecasts. While most of the expenditure takes place within a three year period the other costs and benefits are spread over a very long term. As we have seen thirty years makes a large difference to traffic flows, household behaviour and income and the mode of transport used.
Taking the M40 extension from Oxford to Birmingham as an example we can illustrate the problem. A general forecast of the vehicles per day between, say, Oxford and Warwick is inadequate. There is also a need to know:
• The traffic split on existing roads (A41, A429 and A34 in this case).
• The modal split of cars, LGV’s, HGV’s, buses and coaches.
• The peak demand periods, how long they last and where they occur.
The forecasts then have to take into account:
• Type of journeys made (work, education, weather) and the number of trips made of each type.
• The modal split of passenger and freight journeys.
• Trips expected to be made along each route.
• Effect of new road on existing roads, transfers to new route and new traffic generated.
Forecasts in traffic planning and COBA
The problem of forecasts is that they are only well informed guesses and can’t anticipate policy changes. The classic example is the M25 where the forecasts suggested that the road would have sufficient capacity for 30 years, it was full the day after it opened because they failed to predict the diversion of local traffic on to the new road and because of increased leisure traffic from south-west London to north London. The forecast flows were 80,000 pcu’s (passenger car units) per day, the current figure is 190,000.
Transport is a derived demand and so traffic forecasts must also take in to account macroeconomic factors. Household income, GDP growth, changing trade patterns, manufacturing output, and changes in land use (such as out of town shopping and entertainment) are all examples of variables determined outside of the transport industry that affect it. The forecasting of transport demands and costs and a realistic appraisal of transport projects therefore requires a wide understanding of trends and developments in the whole economy.
Criticisms of COBA
It is not a comprehensive CBA - COBA only considers the benefits to users of the new road. It therefore ignores the effects on other groups - externalities.
Environmental issues are ignored - there is a loss of land when new roads are built. The environmental effects are;
+ Traffic noise
+ Visual intrusion
+ Pollution
+ Loss of amenities
The Department of Transport now incorporates an assessment of environmental damage (the Environmental Statement) into the appraisal process, but no monetary value is placed on this. This is required by EU law.
Value judgements are involved - the valuation of saved time at particular wage rates for example.
Indirect effects of new projects are not accounted for - for example the effect of building a new motorway to a depressed region will encourage firms to move to the area.
Not all projects get as far as COBA evaluation - to achieve the desired results the list of projects assessed must be comprehensive. However many schemes never make it to the top of the priority list to gain assessment. Important projects may be missed.
COBA cannot be applied to urban schemes - COBA cannot cope with inconsistencies which may arise for peak and off-peak data, nor with the interaction between functions such as blocking back. The lower minimum speeds and longer maximum delays of urban areas are also not allowed for in COBA.
The COBA approach is shown by the case study of the M4 near Newbury on the next page.
The ‘new approach to appraisal’
The dissatisfaction with COBA has been recognised by the introduction of the Appraisal Summary Table (AST) by the ‘Roads Review. The DETR unit responsible for COBA have yet to work out a way of performing a complete CBA (for example valuing loss of countryside), but the table tries to take this sort of thing into account and balance the strict economic costs of COBA.
To achieve this objective the Government has developed a new approach to appraisal which is broadly based and takes account of five criteria:
environmental impact;
safety;
economy;
accessibility; and
integration.
The AST tries to:
understand the problem and ask what priority it deserves;
identify a range of options;
appraise options to determine the extent to which they meet the Government's objectives as cost effectively as possible, given the need for benefits to outweigh costs and to achieve value for money.
The criteria have been divided into a number of sub-criteria, reflecting the wide variety of impacts arising from schemes.
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