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Statistical Bulletin Trn/2001/2 Transport series
Bus and Coach Statistics: 1999-2000 

If you have any enquiries, comments or suggestions that you wish to make, please contact us at transtat@scotland.gsi.gov.uk

Published March 2001 A SCOTTISH EXECUTIVE NATIONAL STATISTICS PUBLICATION

This document is also available in pdf format (1.1MB)

Contents

1 Introduction
2 Main Points
3 Commentary
4 Notes and Sources

Tables
Table 1.1 Vehicle kilometres by type of service
Table 1.2 Local Bus Services : Vehicle kilometres per head of population, and on commercial and on subsidised services
Table 2.1 Local bus services : Passenger journeys by area
Table 2.2 Local bus services : Passenger journeys per head of population
Table 3.1 Local bus services : fare indices
Table 3.2 Passenger transport price indices for Great Britain
Table 4.1 Passenger Receipts in Scotland by type of service
Table 4.2 Local bus services: Passenger receipts by area
Table 5.1 Local bus services: Government support for Great Britain
Table 5.2 Local bus services: Public transport support by area
Table 5.3 Local bus services: Concessionary fare reimbursement by area
Table 6.1 Local bus services: Operating costs per vehicle kilometre by area
Table 6.2 Local bus services: Operating costs per passenger journey by area
Table 7.1 Vehicle stock by type of vehicle
Table 7.2 Vehicle stock (Scotland) with a super low floor design, powered lift or ramp, or kneeling mechansim by type of vehicle
Table 8.1 Staff employed: by type of employment
Table 9.1 Local bus services: ESTIMATED vehicle kilometres
Table 9.2 Local bus services: ESTIMATED passenger journeys
Table 10.1 Local Bus Services

Charts
Chart A: Distance travelled by bus services (Scotland)
Chart B: Distance travelled by local bus services per head of population
Chart C: Passenger journeys on local bus services (Scotland)
Chart D: Passenger journeys on local bus services per head of population
Chart E: Local bus service fare indices and passenger transport fare indices
Chart F: Passenger receipts; public transport support and concessionary fare reimbursement (Scotland)
Chart G: Vehicle Stock (Scotland)
Chart H: Staff Employed (Scotland)
Chart I: Estimated distance travelled by local bus services for former regions
Chart J: Estimated distance travelled by local bus services for former regions
Chart K: Estimated passenger journeys on local bus services for former regions
Chart L: Estimated passenger journeys on local bus services for former regions
Chart M: Local bus services: passenger journeys and distance travelled by services (vehicle kilometres) - Scotland
logarithmic scale
Scottish Executive Transport Statistics Publications
Scottish Executive Statistical Services
Correspondence and Enquiries

1. Introduction

1.1 This Bulletin describes the trends in Scottish bus and coach services over the past ten years, from 1989-90 to 1999-2000, using statistics which were provided by the Department of the Environment, Transport and the Regions. A summary table provides some key figures over a longer period, including 1985-86, the last full year prior to the deregulation of bus services outside London, which took place during 1986-87. The tables include, in many cases, comparable statistics for Great Britain and/or for "Great Britain outside London", where this is more appropriate.

1.2 The commentary generally focuses on the latest year (1999-2000) and compares it with the previous year, and with trends over the past ten years. The commentary also compares some trends for Scotland with the corresponding trends for Great Britain (or for Great Britain outwith London).

1.3 This bulletin provides, for the first time, statistics on the number of Public Service Vehicles that have low floors, powered lifts/ramps, or kneeling mechanisms that allow easy access for disabled or infirm persons.

2. Main Points

2.1 Scottish bus and coach services:

• travelled 492 million vehicle kilometres in 1999-2000, 5% less than in the previous year.
• travelled 2% less than in 1989-90, compared with a 5% rise for Great Britain as a whole.

2.2 The distance travelled by local bus services in Scotland:

• was 362 million vehicle kilometres in 1999-2000, 1% more than the previous year.
• has increased by 8% in ten years, compared with an increase of 6% in Great Britain.
• per head of population in 1999-2000 was 57% higher than Great Britain.
• on subsidised services has increased by 36% over the past 10 years, compared with 2% in Great Britain outwith London.

2.3 The total number of passenger journeys on local bus services in Scotland:

• was 431 million in 1999-2000, 4% more than in the previous year - but this was only the third increase since 1975.
• fell by 30% between 1989-90 and 1999-2000, compared with 16% in Great Britain and 24% for Great Britain outwith London.
• represented 84 journeys per head of population in 1999-2000, 14% higher than the corresponding figure for Great Britain.

2.4 In real terms, fares on local bus services in Scotland were 1% higher in 1999-2000 than in the previous year. They increased by 24% over the past ten years, compared with 23% for Great Britain. Over the same 10 year period, motoring costs rose by 8% in real terms.

2.5 Passenger receipts from Scottish bus and coach services totalled £428 million in 1999-2000, in real terms £3 million less than the previous year and £9 million less than ten years earlier. Local bus passenger receipts in Scotland in 1999-2000 were £312 million and, in real terms, fell by 6% over the past ten years, compared with almost no change for Great Britain, and a fall of 6% for Great Britain outwith London.

2.6 Public transport support for local bus services in Scotland in 1999-2000 was £27 million, 17% more in real terms than in 1989-90, compared with falls of 29% for Great Britain, and 4% for Great Britain outwith London.

2.7 In Scotland, over the past ten years, the number of single decker buses has increased by 18%, the number of double deckers has reduced by 32%, and staff numbers have fallen by 14%. In consequence, operating costs per vehicle kilometre (including depreciation) were 31% lower in real terms than ten years earlier.

2.8 Since 1975, Scotland has seen a 52% reduction in the number of local bus passenger journeys but a 7% increase in the distance travelled by local bus services. This compares with a 43% reduction in passenger journeys for Great Britain as a whole and an increase of 6% in vehicle kilometres.

3. Commentary

3.1 Distance travelled - by type of service (Table 1.1 and Chart A)

Scottish bus and coach services travelled 492 million vehicle kilometres in 1999-2000, 5% less than in the previous year. There was a fall of 2% since 1989-90, compared with a 5% rise in the corresponding figure for Great Britain as a whole.

The distance travelled by local bus services in Scotland in 1999-2000 was 362 million vehicle kilometres, 1% more than in the previous year, and 8% higher than in 1989-90.  The increase in distance travelled over the past ten years by local bus services in Great Britain was 6%.

The distance travelled by other (non-local) Scottish bus services in 1999-2000 was 130 million vehicle kilometres, 19% less than in the previous year. Over the past ten years, the distance travelled by other (non-local) Scottish bus services fell by 22%, in contrast to a 2% increase in other (non-local) bus services in Great Britain as a whole. The Scottish figure had declined between 1991-92 and 1994-95, then rose to a peak of 178 million vehicle kilometres in 1997-98 before subsequent falls led to its lowest level for the past ten years.

3.2 Local bus services - distance travelled per head of population (Table 1.2 and Chart B)

The distance travelled by local bus services per head of population has been consistently higher in Scotland than Great Britain (as can be seen clearly in chart B).  In 1999-2000 it was almost 71 vehicle kilometres per capita in Scotland compared with 45 in Great Britain, and so was 57% higher in Scotland.

3.3 Local bus services - Commercial and Subsidised services’ distance travelled (Table 1.2 and Chart A)

The distance travelled by commercial local bus services in Scotland in 1999-2000 remained the same as the previous year at 298 million vehicle kilometres, but was 3% higher than in 1989-90.

The distance travelled by subsidised local bus services in Scotland in 1999-2000 increased by 7% on the previous year, making it the highest level since these records began, 36% higher than in 1989-90.  The corresponding rise in "Great Britain outside London" since 1989-90 was 2%, a much smaller increase than in Scotland.

The subsidised local bus services’ share of the total distance travelled by all local bus services in 1999-2000 was about 18% in Scotland, compared with about 17% for "Great Britain outside London".

3.4 Passenger journeys - local bus services (Table 2.1 and Charts C & Chart D)

In Scotland, there were 431 million passenger journeys on local bus services in 1999-2000. This was 4% more than the previous year, a greater rise than the 1% increase for Great Britain as a whole. However, the Scottish total for 1999-2000 was 30% less than in 1989-90, having fallen in every year since then until the increase in 1999-2000. The corresponding fall over the past ten years in Great Britain of 16% was less than in Scotland, as was the fall for "Great Britain outside London" of 24%. The number of passenger journeys on local bus services in Scotland has generally fallen each year since 1975. The increase in 1999-2000 was only the third since 1975.

The number of passenger journeys on local bus services in Scotland in 1999-2000 represented 84 journeys per head of population, compared with 74 per head of population for Great Britain, and so was 14% higher in Scotland. However, the difference between Scotland and Great Britain as a whole had been reducing: in 1993-94 the Scottish figure was 32% higher than the figure for Great Britain. This reduction in the difference can be seen clearly in Chart D, which shows the Scottish figure had been falling steadily towards the level for Great Britain as a whole (although in 1999-2000 passenger numbers increased more sharply in Scotland than in Great Britain as a whole).

3.5 Passenger Fares (Table 3.1 and Chart E)

Bus passenger fares on local services in Scotland in 1999-2000 increased in real terms by 1% over the previous year, which is less than the increase of 2% in Great Britain. The increase in fares in real terms over the past ten years in Scotland was 24%, which is almost the same as the 23% rise for Great Britain.

3.6 Passenger price indices for different modes of transport - in Great Britain

(Table 3.2 and Chart E)

While fares for local bus services in Great Britain have risen by 23% in real terms since 1989-90, and rail fares by a similar 20%, motoring costs in Great Britain have, in real terms, increased by only 8% over the period to the 1999-2000 financial year.  (A corresponding range of price indices for Scotland is not available).

3.7 Passenger receipts (Tables 4.1 and Table 4.2, and Chart F)

The total of Scottish bus and coach service passenger receipts, from local and other services, was £428 million in 1999-2000, in real terms a fall of £3 million (1%) from the previous year, and £9 million (2%) less than ten years earlier. Total passenger receipts have not changed greatly during the period, remaining between £419 million and £440 million at 1999-2000 prices.

Passenger receipts on local bus services were £312 million in 1999-2000, a rise of 2% in real terms on the previous year but a fall of 6% over ten years. Local bus service passenger receipts have in the last ten years ranged from £307 million to £337 million at 1999-2000 prices. However, passenger receipts for other (non-local) bus and coach services in 1999-2000 were £116 million, 6% lower in real terms than the previous year, but 10% higher than in 1989-90. Over the ten years they varied between £100 million and £124 million at 1999-2000 prices, but there were several years in which there was very little change in real terms.

The fall in real terms in local bus service passenger receipts over the past ten years was similar in percentage terms in Scotland and in Great Britain outside London, but Great Britain as a whole had very little change over the same period. In both Scotland and Great Britain outwith London, the fall in real terms since 1989-90 was 6%, but in Great Britain as a whole passenger receipts in 1999-2000 were, in real terms, at almost the same level as 1989-90.

3.8 Public Transport Support - local bus services (Table 5.2 and Chart F)

Public transport support for local bus services in Scotland in 1999-2000 was £27 million, in real terms a 7% decrease on the previous year, but 17% more than ten years earlier. In comparison, over the same 10 year period, there has been a fall in support of 29% in real terms for Great Britain (4% for Great Britain outwith London).

3.9 Concessionary Fare Reimbursement - local bus services (Table 5.3 and Chart F)

Concessionary fare reimbursement on local bus services in Scotland in 1999-2000 was £42 million, in real terms 2% less than the previous year, and 19% less than in 1989-90.  In Great Britain there was a decrease of 12% in real terms over the past ten years.

3.10 Operating costs per vehicle kilometre - local bus services (Table 6.1)

The estimated average operating cost (including depreciation) of local bus services in Scotland, was 73 pence per vehicle-kilometre in 1999-2000, in real terms 7% less than in the previous year, and 31% lower than ten years earlier.

The corresponding estimated average operating cost (including depreciation) for Great Britain was 92 pence per vehicle kilometre, and the fall in real terms over the past ten years was 25%.

3.11 Operating costs per passenger journey - local bus services (Table 6.2)

The estimated average operating cost (including depreciation) per passenger journey for local bus services in Scotland in 1999-2000 was 61 pence, in real terms a 9% decrease from the previous year but a 5% increase on ten years ago.

The operating cost per passenger journey for Great Britain was 56 pence, less than in Scotland, and had fallen by 6% over the past ten years.

3.12 Number of buses and coaches (Tables 7.1 andTable 7.2, and Chart G)

There was very little change in the overall total number of buses and coaches in Scotland in 1999-2000 from the previous year, but it was 2% higher than ten years earlier, mainly due to the increase between 1989-90 and 1993-94 (there has been little change since then).

Over the period since 1989-90, there has been an 18% increase in the number of single deckers, from 6,000 to 7,100. This was partly due to a rise in the number of 17-35 seat buses (mainly between 1991-92 and 1996-97 - there appears to have been a reduction since then). Also, the number of single deckers with 36+ seats has increased for the fourth year in succession: in 1999-2000 there were 4,500, 15% more than ten years earlier. In contrast, the number of double deckers fell by 32% from 2,800 in 1989-90 to 1,900 in 1999-2000, with most of the fall being after 1991-92.

In Great Britain, the 8% increase in the total number of buses over the past ten years was greater than Scotland’s 2% rise.  The number of 17-35 seat buses in Great Britain rose by 31%, and in Scotland by around 36% (calculated from the rounded estimates). The number of double deckers in Great Britain fell by 27% in ten years, and by 32% in Scotland.

Information about the numbers of buses and coaches which have low floors, powered lifts or ramps, or kneeling mechanisms has only been collected with effect from the return for the 1997-98 financial year. In 1999-2000, roughly a sixth of buses and coaches had a low floor, powered lift or ramp, or a kneeling mechanism. It should be noted that some of the apparent year-to-year changes may be misleading, possibly being due to the effects of sampling variability - see the "Notes and Sources" in section 4.

3.13 Staff Employed (Table 8.1 and Chart H)

There were 17,100 staff employed by bus and coach operators in Scotland in 1999-2000, 400 (2%) more than the previous year, but 14% fewer than in 1989-90. The 14% reduction in staff in Scotland was greater than the 4% fall in Great Britain over the same period.

In Scotland there was a rise in the number of "platform staff" (including drivers, conductors and other on-vehicle staff) of 600 (5%) when compared with the previous year. In Great Britain "platform staff" increased by 2% over the same period. In 1999-2000, maintenance staff in Scotland fell by 300 (11%) on the previous year, and there was a reduction in maintenance staff of 39% over the ten years, mainly since 1991-92.

3.14 Local bus services: Estimated vehicle kilometres and passenger journeys for areas within Scotland (Tables 9.1 and Table 9.2, and Charts I Chart J Chart K and Chart L)

Estimates for areas within Scotland can be produced from the statistical returns but it should be noted that the statistical returns were not designed to produce figures for parts of Scotland, and therefore some of the estimates may be subject to considerable uncertainty. The reasons for this are explained in the "Notes and Sources" section.

The estimates for different parts of Scotland that are given in this bulletin should therefore be seen as a general guide to the levels and trends, with the occasional "hiccup" in the series being a reminder that the estimates may be affected by the kinds of factors described in the "Notes and Sources" and so are not necessarily reliable. This point is particularly relevant in the case of the estimates for the areas with the smallest populations where (for example) apparently large year-to-year fluctuations could be caused by the "luck of the draw" including in the sample several operators in one year and few operators in another year - or could reflect genuine changes in the level of provision and patronage of services in those areas due to (e.g.) expansion or contraction by one or more operators.

The estimates suggest that, over the past ten years, there have been increases in the number of vehicle kilometres run by local bus services in most parts of Scotland, with a couple of apparent exceptions. At the same time, the numbers of passenger journeys have fallen in all the main populated areas, with the scale of the percentage reduction apparently varying between areas.

3.15 Local bus services: Longer term trends (Table 10.1 and Chart M)

Some key statistics are available for local bus services for years from 1975. However, due to changes in methods of collecting the data, figures for years prior to 1985-86, which was the last full year prior to deregulation, may be less reliable than those for later years.

The distance travelled (vehicle kilometres) by local bus services in Scotland has increased by 7% since 1975, mainly due to an increase between 1985 and 1994. (Prior to 1985, there had been falls in most years since 1975). However, the number of passenger journeys has decreased by 52% since 1975, with increases in only three of the 24 years since 1975: the rise in 1999-2000 was the first since 1987-88.

For Great Britain as a whole, the distance travelled (vehicle kilometres) rose by 6% and the number of passenger journeys fell by 43% between 1975 and 1999-2000.

4. Notes and Sources

4.1 General Points

In the tables, ".." indicates "not available", and "-" indicates "nil or negligible".

Where figures are rounded, a total which was calculated by adding together the "unrounded" versions of the underlying numbers, and then rounding the result, may appear to differ from the sum of its parts. Similarly, there may appear to be minor discrepancies in the case of percentages calculated from "unrounded" underlying numbers.

4.2 Definitions

"Local" bus service: one which is available to the general public, where passengers pay separate fares and travel a radial distance no greater than 15 miles / 24 kilometres from the point of boarding. (For the earliest years, these figures are for the former category of "stage" services. The definitions of the types of service changed on 6 January 1986, when the term "local service" replaced the former term "stage service".)

"Other services": include contract, private hire, express journeys, excursions and tours which are not registered as local services.

Passenger journeys: each trip made by a passenger on one vehicle on one route counts as a separate journey. Return tickets therefore count as two passenger journeys. The numbers of passenger journeys using season tickets or travel passes may be estimated by operators.

Vehicle kilometres: estimates include some categories of empty running of buses (eg between garage and terminus) but exclude driver instruction and vehicle testing.

Local bus fare indices: Information about the size of each fares change is supplied by a panel of large operators. Indices are obtained by averaging charges using weights based on receipts from passengers (excluding concessionary fare reimbursement from local authorities). In theory, therefore, the index measures the change in the average charge to the fare-paying passenger.

Commercial services: are those run without direct financial support from a local transport authority. They are still eligible for central Government subsidy in the form of fuel duty rebate and (where applicable) for concessionary fare reimbursement from local transport authorities.

Subsidised services: are those considered socially necessary and run under contract to local transport authorities with some direct subsidy. They include a few services subsidised without competitive tendering, under Section 91 of the Transport Act 1985 (‘de minimis’ arrangements).

Concessionary fare reimbursement: Local authorities and PTAs are able to provide concessionary fare schemes for groups such as elderly people and disabled people and (since 26 October 1986) children. Authorities reimburse operators for revenue lost as a result of their participation in the schemes, after taking into account income from the extra travel generated. The reimbursement by authorities should be seen as a subsidy to the passenger, not to the operator. These schemes should not be confused with the reductions offered to children, for example, by many operators on commercial grounds.

Staff employed: Platform staff comprise drivers, conductors and any other on-vehicle staff; maintenance staff include all employees engaged on cleaning, repair, service or maintenance of vehicles, while other staff include administrative staff. There may be some duplication of functions, particularly amongst the smaller operators.

4.3 The Public Service Vehicle Operator Annual Returns

The basis for most of the statistics in this Bulletin is the annual returns which a sample of Public Service Vehicle operators across Great Britain make to the Department of the Environment, Transport and the Regions (DETR). Further information is contained in the DETR publications Transport Statistics Great Britain, Focus on Public Transport and Bulletin of Public Transport Statistics. Enquiries regarding the statistics should be made to Paul O’Hara of DETR (tel: 0207 944 3076).

The sample is stratified by size of operator, based on the numbers of vehicles that they are licenced to run (their numbers of licence discs). With effect from the 1997-98 survey, it includes all operators with 30+ vehicles, and a random sample of smaller operators (who are selected with probabilities depending upon their numbers of discs). The survey design and sampling fractions are a compromise between the optimal designs for local and other (non-local) services. As the table below shows, large operators are responsible for the major share of local work, so a smaller sample of small and medium sized operators would be acceptable for the purposes of producing figures for local services alone. However, the small and medium-sized operators provide the majority of non-local services, and therefore the sample must include enough of them to produce reasonable estimates for non-local services.

Sampling fractions and 1999/2000 distributions by numbers of discs (GB figures)

* See section 4.5. The actual "grossing-up" factors for each size band depend on the level of response. The factors shown here assume 100% response rates, but the factors actually used are higher, because of non-response.
** Small operators, in particular, enter or leave the industry throughout the year.

Prior to the 1999-2000 survey, the method of selecting the sample was based purely upon the number of discs: there was no "area stratification" to take account of where in Great Britain the operator was based. While the database was arranged in such a way as to ensure that the GB-wide sampling procedure would provide reasonable coverage of operators based in Scotland (and operators based in Wales), the "luck of the draw" could lead to the sample of operators which was selected for an area within Scotland being unrepresentative of the operators in that area. For example, the sample for an area might have contained significantly more (or significantly fewer) operators in a particular size-band than would have been expected from knowledge of the sampling percentage and of the "population" number of operators in that size-band in that area.

For the 1999-2000 survey, in order to improve the estimates for smaller areas, DETR scrutinised the randomly-selected sample and, for each size band in each local authority area, compared the number who had been selected for inclusion in the sample with the number of operators shown in the sampling frame. In cases where the sample appeared to contain too few (or too many) operators in a particular size-band in a particular local authority area, DETR changed the composition of the sample, adding (or removing) operators in that size-band who were based in that local authority area, thus spreading the adjusted sample more evenly across local authority areas. Therefore, the results for areas within Scotland ought to be more reliable for 1999-2000 than for earlier years - but see section 4.8.

However, there are limits to what DETR can do to ensure that the sample for an area is representative. For example, suppose that a particular area has only one operator in a particular size-band (eg "20-29 discs", for which the sampling fraction is 60%). Clearly, all DETR can do is to include that operator in the sample in some years, and exclude it from the sample in other years: DETR cannot include 60% of the operator in the sample in every year. A further complication is a "survey holiday" voucher scheme, which is designed to reduce the burden on small businesses by giving periods of exemption from surveys. The first such "survey holiday" applies to operators with nine or fewer staff who were sampled in 1997-98, who will not be eligible for selection again until the survey for 2000-01. This scheme limits the number of smaller operators who are available for selection in each year, and hence limits the DETR's ability to choose a sample which is as representative as possible for each area.

Finally, it should be noted that small operators enter and leave the industry each year, which makes consistency of sampling in the smaller fleet size groups more difficult.

The figures for Scotland for non-local services are derived from the returns made by the operators who are based in Scotland, and so will include services into England which are run by operators based in Scotland, and will exclude services into Scotland which are run by operators based in England. (NB: a large group, such as Stagecoach, is not treated as a single operator: there will be a separate statistical return for each of its subsidiary companies.)

4.4 Estimation of certain breakdowns, in cases where the survey does not collect information for smaller operators

In order to reduce the burden on respondents to the survey, the smaller operators receive a simplified questionnaire, which does not ask for certain pieces of information. For example, smaller operators supply only an overall total figure for their income from local services: unlike the larger operators, they do not provide a breakdown between "passenger receipts", "public transport support", "concessionary fare reimbursement", "contract payments" and "fuel duty rebate".

In order to produce overall totals for the different types of income from local services, DETR must estimate the breakdown of local service income between these headings for the smaller operators. DETR does this by assuming that, for each small operator which responds to the survey, the percentage breakdown of income between these headings is the same as the overall national (GB) percentage breakdown of such income for all the large operators taken together. Thus, if "passenger receipts" accounted for (say) 80% of the total local service income of all large operators in GB, DETR would assume (for the purposes of estimating the overall totals) that passenger receipts accounted for 80% of the local service income of each of the smaller operators who responded to the survey.

The survey obtains, from the larger operators, information about their expenditure (operating expenditure on local services and on other services, administration expenditure and depreciation). It does not ask the smaller operators to provide this, but the effect of this on the calculation of costs per vehicle kilometre and per passenger journey is thought to be small.

4.5 Estimation of totals for all smaller operators, by "grossing-up" the returns from the smaller operators

The figures for each smaller operator (including those income breakdown figures which DETR estimated - see above) are "grossed-up" using a grossing-up factor which is the inverse of the achieved sampling fraction, and therefore makes an allowance for any non-responding small operators (as the grossing-up factors are based upon the numbers of responses obtained for each fleet size group). For example, as roughly 5% of the smallest operators respond to the survey, the grossing-up factor for them will be about 20. (While the aim may be to sample 1-in-20 of the smallest operators, the survey is unlikely to obtain returns from exactly 1 in 20 of them: for example, if there were 250 such operators, and 12 of them were chosen for the survey and made returns, the grossing-up factor would be 250 divided by 12, which is about 20.8). DETR calculates the "grossing-up" factors separately for Scotland, England and Wales: the Scottish grossing-up factor for a particular size-band is simply the total number of Scottish operators in that size-band divided by the number of them who made returns.

4.6 Estimation of figures for areas within Scotland

The larger operators (those with over 1 million vehicle-miles run on local services) are asked to split their local service passenger numbers, vehicle miles and income of various kinds between the local government areas in which they operate. Up to and including the 1996-97 returns, the breakdown was requested in terms of the former Regions and Island Areas; from the 1997-98 returns it is in terms of the present Councils. (In order to provide a time-series, the present Councils have been grouped together on the basis of the former Regions for the purpose of producing Tables 9.1 and 9.2.)

The methods that operators use to split their totals between areas will depend upon the kind of information that is available from their businesses’ records, and may vary from operator to operator: some may have administrative systems that provide breakdowns of passenger numbers etc by area that are more detailed than those of other operators. There is no recommended method: all that the instructions for the completion of the return ask is that "if exact figures are not available, please give the approximate proportion or percentage in each [area]". In some cases, therefore, an operator might only be able to provide a rough estimate of the breakdown (eg 60% in area A, 30% in area B, 10% in area C). It may be that, from time to time, an operator changes the way in which it estimates or calculates the split of its figures between the areas which it serves - if so, this may cause a discontinuity in the time-series for those areas.

The smaller operators are not asked to provide such a breakdown. Instead, DETR assumes that all a small operator’s activity is in the area in which the operator’s office is situated. As each small operator’s figures are grossed-up as part of the process of producing estimates which cover all small operators, it follows that the grossed-up estimates based upon a small operator’s return are counted wholly against the one area.

4.7 DETR’s rules on the possible disclosure of figures for an area

When the data are collected from Scottish operators, an undertaking is given that (unless they give written permission) access to their figures will be restricted to the DETR and Scottish Executive staff who deal with public service vehicle statistics. Therefore, the need to protect the confidentiality of the information which is provided in the statistical returns may prevent the disclosure of the totals for an area without the permission of the larger operators in that area. For example, if the two largest operators in an area together account for a very large proportion of the total patronage, one of them might be able to deduce the approximate size of the other’s business from any totals that were published for that area. In such a case, therefore, one would need the permission of both large operators before one could disclose the totals for that area. DETR uses the following rule to determine whether or not the totals for an area may be disclosed without the permission of the larger operators in the area:

a total for an area is NOT disclosable (without the permission of the larger operators in the area) if
either i. the largest operator accounts for over 60% of the total for the area
or ii. the second largest operator accounts for over 60% of the rest

These rules mean that figures for several parts of Scotland cannot be disclosed without the permission of the larger operators in those areas. Therefore, as the collector of the statistics, DETR kindly wrote to the largest operators in Scotland, asking if they would agree to the figures from their statistical returns being used to produce totals for areas within Scotland which the Scottish Executive would publish. We are very grateful to all the major operators who agreed that the Scottish Executive could use their figures in this way.

4.8 The uncertainties about the estimates for parts of Scotland

It will be seen that there are some large year-to-year changes in the estimates for some areas, and that occasionally one year's figure stands out as unusually high or unusually low. It must always be remembered that the survey is not designed to produce reliable figures for areas within Scotland (such as the former regions or the current councils).

For the years prior to 1999-2000, the estimates for any areas which have only a few operators may be subject to what could occasionally be considerable sampling errors, if those operators are small operators, since the "luck of the draw" could occasionally include most of the operators in that area in the sample in one year (leading to the grossed-up estimates being far too high) and there could occasionally be few or none of them in the sample in another year (leading to the grossed-up estimates being too low).

Although DETR adjusted the sample for 1999-2000, with the aim of making it more representative of each area, this does not guarantee that the results for each area for 1999-2000 will be reliable. For example, the figures for an area would be too low if returns were made by fewer operators than would be expected for that area, which could happen due to non-response to the survey by a higher than average proportion of the operators in that area.

Unreliability may also be an inevitable consequence of an area having only a small number of operators. For example, suppose that a particular area has only one operator with 20-29 discs. The sampling fraction for that size-band is 60%. In the years in which that operator responds to the survey, its figures will be multiplied by the grossing-up factor for the "20-29 discs" size-band (i.e. 1.67 - or more, if there was non-response by some Scottish operators in that band), and therefore the survey's estimate of the total for the area will be too high (all else being equal). In the years in which that operator is not selected for inclusion in the sample (and in any years in which the operator is included in the sample but fails to respond), the operator will make no contribution to the survey's estimate of the total for the area, which will therefore be too low (all else being equal). For this reason, it may be impossible for the survey ever to provide the correct figures for some areas.

It follows that some of the estimates that are provided in Tables 9.1 and 9.2 may be subject to considerable uncertainty. For example, an area could appear to have a particularly large increase in its estimate in one year because:

The estimates for different parts of Scotland provided in Tables 9.1 and 9.2 are therefore a general guide to the way in which the levels of patronage and service have changed in each of these areas over the past 10-or-so years. The "hiccups" in the series are a reminder that the estimates may be affected by sampling quirks etc, and so are not necessarily reliable. In order to see better the overall trends in local bus service provision and patronage in some areas, users of the statistics could take (say) three-year moving averages of the estimates for those areas, as moving averages should be less affected by sampling and estimation problems.

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