TRANSPORT and ROAD RESEARCH LABORATORY

Department of the Environment Department of Transport

SUPPLEMENTARY REPORT 581

ROAD SAFETY AND VALUE FOR MONEY

by

Barbara E Sabey BSc FlnstP FIHE

(The text of a paper presented to the Seminar 'Road safety - remedial action and the local authorities' organised by the Institution of Municipal Engineers in London, October 1979)

Any views expressed in this Report are not necessarily those of the Department of the Environment or of the Department of Transport

Accident Investigation Division Safety Department

Transport and Road Research Laboratory Crowthome, Berkshire

1980 ISSN 0305-1315

Ownership of the Transport Research Laboratory was transferred from the Department of Transport to a subsidiary of the Transport Research Foundation on 1 st April 1996.

This report has been reproduced by permission of the Controller of HMSO. Extracts from the text may be reproduced, except for commercial purposes, provided the source is acknowledged.

Abstract

1. Introduction

2. Value of road accidents

3. Basis for assessment

4. Contributory factors

5. Potential for savings

6. Discussion of relative returns

7. Local authority priorities

8. Acknowledgements

9. References

CONTENTS

Page

1

1

2

3

4

8

9

12

13

13

(6") CRO IYN COPYRIGHT 1980 Extracts from the text may be reproduced, except for

commercial purposes, provided the source is acknowledged

ROAD SAFETY AND VALUE FOR MONEY

ABSTRACT

The current state of knowledge on factors which may aid decisions to achieve value for money in road safety is outlined. The discussion includes consideration of the monetary value placed on road accidents, the basis for assessment of priorities, contributory factors in accidents, and the options for remedial action in the fields of road engineering, vehicle design and usage, and human behaviour.

Assessments are made of the relative costs of implementation of, and likely returns from, different remedial options. It is concluded that in seeking priorities for action to reduce the road accident toll, a balance between short and long term returns needs to be made. Where Local Authorities are concerned, the short term benefits will undoubtedly come from application of low cost road engineering measures. Education, training and publicity have their place in support o f engineering measures, and will assume even greater importance in the long term.

1. INTRODUCTION

In considering road safety and value for money it is necessary Ftrst to ask what is meant by 'safety ' , and further

what is meant by 'value'.

The term 'safety' implies that no accidents are acceptable, but in contrast to the fields of aviation and rail

transport where this is the criterion used, the reality of the situation on the road is that, perhaps because of the

dominance of private transport involving units of one or only a small number of people, a substantial accident risk

has been an inherent part of the development of road transport, as regards the road itself, the vehicles and the people

involved. That accidents will continue to occur at a substantial level has therefore to be tolerated, but is there an

acceptable level? This question is highlighted whenever there are demands for some engineering deficiency (whether

road or vehicle) to be rectified without reference to the cost involved. Inevitably, in the end, it has to be recognised

that there is no absolute level of acceptability and the best that can be done is to at tempt to assess priorities for

action which will give the optimum returns for expenditure of the resource money available. This approach however

begs the question of how much money should be available in total.

The returns for expenditure on safety remedial measures, or the 'value', are complex. Reduction of road

accidents may save death, alleviate injury, reduce property damage, ease traffic and transport congestion, and

mitigate suffering and inconvenience. The scales on which these benefits are measured are normally very different,

so it is necessary to try to assess their value on some common scale - that o f money. Even then it is not possible

to avoid tl~e emotional value which is attached to individual accidents occurring in dramatic situations.

Acknowledging these uncertainties, this report outlines the current state of knowledge on factors which may

aid decisions to achieve value for money in road safety. It also attempts to indicate the potential for savings in

accidents or injuries on the basis of proven remedial measures and relate this to the resources needed and the

financial returns from such measures.

2. VALUE OF ROAD ACCIDENTS

The general principles of costing road accidents in economic terms are to evaluate the resource costs for reported

injury accidents, together with an estimate ( f rom insurance claims data) for non-injury accidents; and to add to them

a notional value for pain, grief and suffering to the casualty, relatives, and friends. Table 1 summarises the costs

used for 19771 , which relate to 6600 deaths, 81 700 serious injuries (usually requiring detention in hospital) and

259 770 lesser injuries reported in the police statistics. It is known that the serious injuries are underestimated by

probably 30 per cent, for which no allowance has been made in the costing. The damage costs include damage

incurred in non-injury accidents reported to insurance companies - estimated to be at least 1% million per year.

TABLE 1

Cost o f road accidents in Great Britain in 1977

RESOURCE COSTS

Lost output

Police and administration

Medical and ambulance

Damage to property

Sub-total

PAIN, GRIEF AND SUFFERING

Total £ million

282

75

44

545

946

347

Fatal

37,450

150

300

820

38,720

25,880

TOTAL 1293 64,600

£ per accident

Serious injury

770

120

510

690

2090

2650

S l i e r injury

20

90

30

480

620

50

4740 670

The resource costs, totalling £946 million, have been fairly reliably assessed. On the other hand the costs

attr ibuted to pain, grief, and suffering are purely notional since, although they are very real costs to society, they

are by their nature not directly quantifiable in monetary terms. A recent appraisal of these figures 2 suggests that

they are not in line with general principles of cost benefit analyses. A survey of studies where researchers have

at tempted to evaluate how an individual values risk has revealed.figures for value of life between 2½ and l0 times

the average of £25 880 used here. Further work is being directed towards getting more realistic figures based on

public attitudes on how much money people are willing to pay for a reduction of correctly perceived risk.

Meantime the average costs given in Table 1 are the ones widely used to assess priorities - in terms of injury

accidents. The latter are used for the very practical reason that non-injury accidents are not consistently nor

reliably reported. Nevertheless one must question whether in terms o f direct economic costs to the community,

more consideration should not be given to saving damage to property, which constitutes so large a proportion of the

resource costs: in other words, applying more effort to reduction in non-injury accidents. This aspect will assume

greater importance as vehicle occupant protective measures become more widely applied - injuries will be reduced,

but not accidents and damage.

2

3. BASIS FOR ASSESSMENT

There are two basic pre-requisites to assess overall priorities for road accident countermeasures: t'trstly, identification

of the main problem areas and factors contributing to accidents; secondly, knowledge of remedial actions which

will be effective.

Simple analysis of the national police statistics on road traffic accidents gives a perspective view of the accident

situation in terms of who is involved (the type of road user), where (urban or rural area, road layout), when (day or

night), under what circumstances (dry or wet, type of collision). Some of the more important problems in terms of

numbers are:

Road users injured

- over one-half killed in urban areas are pedestrians

- nearly three-fifths killed in rural areas are car occupants

- in total, one-fifth of all casualties are pedestrians, one-quarter cyclists, two-fifths car occupants.

Environment

- three-quarters of accidents are in urban areas

- two-thirds of urban accidents are at junctions

(in contrast, injury accidents on motorways are under 1½ per cent of all injury accidents)

- one-third of accidents occur in darkness

- one-third of accidents occur on wet roads.

Vehicles and collisions

- three-quarters of accidents involve cars

- nearly one-third of urban accidents involve a pedestrian and only one vehicle

- one-third of rural accidents involve only one vehicle

(Only 6 per cent of accidents involve 3 or more vehicles).

Figures are useful to describe the scale of the problem in this way, but they cannot convey its nature - how

and why accidents occur. To do this it is necessary to undertake multi-disciplinary studies of accidents which

approach the problem from a broad viewpoint and without bias. Then only is it possible to assess the relative roles

of the many aspects of engineering and behavioural features of accident occurrence, and their complex inter-

relationships. One such multi-disciplinary study carried out by the Transport and Road Research Laboratory over

the period 1970 to 19743 has been widely quoted: the broad results that are remembered are that 95 per cent of

accidents involve a human failing, 28 per cent a deficiency of the road network, ar).d 8½ per cent a vehicle defect.

Without further qualification, these figures can mislead, and have done so. It is too easy to conclude that all effort

should be applied to influencing human behaviour directly, without taking into account the detailed circumstances,

the multiplicity of factors which lead to accident occurrence, and the chances of success of measures applied.

- \

When considering remedial measures to reduce accidents it must be borne in mind that the most effective

remedy is not necessarily related directly to the main cause of the accident and may even lie in a different area of

the road, vehicle or road user. This is particularly true of accidents in which the road user fails to cope with the

road environment; in many accidents the primary cause may be said to be the driver's lack of skill, but engineering

remedies to improve the road are cheaper and easier to effect than training the driver to the necessary degree of skill.

Further, even in circumstances in which human error or impairment has been judged to be the sole contributor, it

may be possible to influence human behaviour more readily by engineering means than by education or enforcement

of legislation. There is also considerable potential for injury reduction even when accidents cannot be avoided.

Although studies of accident 'causation' indicate that ultimately the greatest potential for accident reduction

lies in influencing human behaviour, it would be impossible at this stage to predict benefits on the basis of causes

or errors alone: in many cases there is no known effective remedy. In recent assessments of the potential for accident

and injury savings the approach therefore has been to consider proven remedies, or measures for which there is strong

evidence of potential benefits, regardless of blame, or resources required.

This report will now highlight some of the more important findings from these studies of contributory factors

in accidents and potential for savings, before discussing their implications and attempting to examine priorities in

terms o f cost o f resources required to apply remedial measures in relation to Financial returns.

4. CONTRIBUTORY FACTORS

The main contributory factors in accidents in the 1970-74 on-the-spot study (that is, factors without which the

accident would have been less likely to happen or at least to have been less serious) are summarised in Table 2.

In total there averaged 2.3 contributory factors per accident; three-quarters of these being human factors, one-fifth

road, and one-twentieth vehicle factors. These were distributed such that human factors contributed to 95 per cent

of all accidents, road factors to 28 per cent and vehicle factors to 8~ per cent: the figures already quoted. The

individ~[al errors are grouped in descending order, of frequency in the table. The manner of executing the driving

task heads the list, the majority of the errors being deficiencies in actions and only 2 per cent of the total being

ascribed to deliberate aggressiveness or irresponsible behaviour. The next most important group relates to perceptual

errors, with impairment third. The relative importance of these groups of factors will become apparent later when

they are examined in the light of potential for savings. There is far less evidence of how to deal with the first two

than with the third. In turn, less is known about influencing human behaviour in general than in correcting road

deficiencies, so the interactions between these groups of data are important: the main interactions are shown in

Table 3.

TABLE 2

Contributory factors in accidents

HUMAN FACTORS

Manner of execution a) deficiency in actions b) deficiency in behaviour

Perceptual errors

Impairment

Lack of skill

Total

Drivers

1153 94

1090

632

462

3431

Number of factors

Pedestrians

107

53

7

167

Total

1260 94

1143

639

462

3598

Per cent of factors

26.9) 2.0)

24.4

13.6

9.8

76.7

Contributory in 1942 accidents - 95 per cent

ROAD FACTORS

Adverse road design

Adverse environment

Inadequate furniture or markings

Obstacles

Total

316

281

157

129

883

6.7

6.0

3.3

2.8

18.8

Contributory in 569 accidents - 28 per cent

VEHICLE FACTORS

Tyres

Brakes

Other defects due to poor maintenance

Unsuitable design

Total

67

65

66

9

207

1.4

1.4

1.4

0.2

4.4

Contributory in 173 accidents - 8½ per cent

TOTAL FACTORS [ ] (in 2042 accidents) 4688 100

TABLE 3

Interactions between contributory factors

Human factors alone 65%

Human + road 24%

Human + vehicle 4½%

Human + road + vehicle 1¼%

Road factors alone 2½%

Road + vehicle ¼%

Vehicle factors alone 2½%

TOTAL 100%

The relative involvement of drivers and pedestrians in this particular study is not characteristic of the country

as a whole since pedestrian accidents are under-reported in the area covered. Nevertheless the data do give information

on blameworthiness for the two different classes of road user. Pedestrians bear a greater part of the blame in accidents

in which they are involved than individual drivers do in non-pedestrian accidents.

TABLE 4

Responsibility for the accident

Primarily at fault

Partially at fault •

No blame allotted

Drivers

41%

19%

40%

Pedestrians

65%

14%

21%

Only in a multi-disciplinary study of this kind can the relative risk of different factors be established, but to

understand more o f the specific problems and how to deal with them it is necessary to refer to the many studies that

have been made which have examined the individual types of factor listed in Table 2. It is not the place to enumerate

all of these here, but some ale of such major importance that they need to be highlighted, particularly in relation to

the potential for savings.

Some of the most important characteristics o f the road user which are relevant are age, sex, behaviour, and

social environment. Age and sex in particular are often blamed in mistake for inexperience, which is more likely to

be associated with the young than the old, and with women who drive less than men. Inexperience in relation to

modes of transport is illustrated in Table 5 which gives casualty rates per head of population 4. The peaks relate to

the age at which the different road users ftrst come into contact with their mode of transport. It is noticeable that

there is a rise in rate for pedestrians in old age, which is not apparent in this particular assessment of rates for other

road users.

TABLE 5

Casualty rates per head of population in 1977

Age group

0 - - 4

5 - - 9

10--14

15--19

20--29

30--59

6 0 - 6 9

70+

All ages

Pedestrians

129

246

160

87

64

95

tls--- 131

Casualties per 100 000 population

Pedal cyclists

4

56

11601

112

32

23

20

13

43

Under 16

Under 17

16/17

17/18-19

Motorcyclists

i

252

49

19

4

132

Car users

94

587

582

290

184

107

279

6

The distinction between age and experience, and the relevance of different kinds of skills and errors to age,

have been examined some years ago, for car drivers in particular. From analyses of insurance claims data Garwood 5 '6

and Munden 7 showed:

(i)

(ii)

the car driver involvement rate in accidents (per distance driven) is U-shaped, with the highest rates for the

young - the shape is illustrated by the latest available driver casualty rates for 1975/76 in Table 6, column 1.

In contrast, the involvements per year show a continued decline at the higher age levels (Table 6, column 2).

the high rate in youth is closely related to inexperience - the data showing the effect of experience, irrespective

of age (Table 6, column 3), can be compared With the age effect. The two ends of the scale are inevitably

biassed by the lower and higher age groups respectively.

(iii) the rise in risk for the older driver is associated with particular kinds of accident, eg involving misjudgement,

slower reactions, and to a small extent poorer vision, although it is clear that older drivers do compensate to

some extent for the physical deficiencies which develop with age. At the same time there is a continued decline

in risk with age for other types of accident, eg involving skidding and other skills related to experience, and

driving with excess alcohol.

A comparison of the sexes 8 has shown that while responsibility for the accident in which they are involved is

about equal for men and women drivers, they drive quite differently and exlfibit different characteristics which can

lead to errors of a different nature. In accidents involving women, lack of experience of driving is manifest in lack

of skill, difficulty in manoeuvring and distraction; in those involving men, the more frequent faults are driving too

fast, improperly overtaking and impairment by alcohol. These differences have implications for planning of driver

training schemes and education.

Although groups of drivers and road users may be identified by behavioural aspects as being high risk, it has

not proved feasible to identify individuals in this way. It may be possible to do so for the drinking driver in the

future when more is known about drinking habits, but in general accidents involve the mass of drivers.

TABLE 6

Variations in car driver involvement rates in accidents with age and experience

Casualty rates per distance driven

Age of driver

17 18 19 20

21-25 26-29 30 -39 40 -49 50-59 6 0 - 6 4 65 -69

70+

1975/76

(1) Rate relative to all ages

5.57 5.07 3.86 4.19 2.19 0.97 0.76 0.61 0.63 0.74 0.93 1.54

Source:

Claims per policy-year

Age of driver

21 -25 26--29 30--39 40--49 50 -59 60--64 65--69

70+

(2) No.

0.15 0.25 0.17 0.13 0.15 0.15 0.12 0.09

Claims per policy-year

police accident reports for injured drivers

Experience in years

0 1 2 3

4 - 8 9 - 1 3

14-18 19-28

(3) No.

0.195 0.17 0.155 0.14 0.14 0.115 0.105 0.12

Source: insurance claims data for male driver policy holders involved in accidents

7

5. POTENTIAL FOR SAVINGS

Available options for reducing accidents or injuries can conveniently be grouped into road engineering measures,

vehicle design and usage, and influencing the road user. The potential for savings by application of established

measures in these different areas is summarised in Table 7 from a detailed appraisal made four years ago 9, which has

recently been updated 10. These savings have been estimated on the basis of measures which have already been

identified as having potential benefits. They take no account of possible future advances in road or vehicle engineering,

or in influencing behaviour.

TABLE 7

Potential for accident and injury reduction in road accidents (based on 1977 data)

Options

ROAD ENGINEERING (low cost measures)

Geometrical design, especially junction design and control

Road surface texture

Road lighting Urban areas: land use, road design and traffic management

VEHICLE SAFETY MEASURES

Primary: Vehicle maintenance Anti-lock brakes and safety tyres Conspicuity of motorcycles

Secondary: Seat belt wearing Other occupant protection measures

OVERALL

Potential: per cent savings

10%

5%

3

5-10

ONE-FIFTH of accidents

2 7 3~

7 5-10

ROAD USERS

Restrictions on drinking and driving More appropriate use of speed limits

Propaganda and information

Enforcement and police presence

Education and training

OVERALL ONE-QUARTER

of casualties

10

5

up to 5

up to 5

upto 5

Other legislation (eg restrictions on parking)

ALL MEASURES

OVERALL

up to 5

ONE-THIRD of accidents

THREE-FIFTHS of injury accidents

No attempt has been made to make recommendations on which decisions should be taken to apply remedial

measures. For many road safety problems there are alternative remedies and the Final choice of remedy implemented

depends on ease of application and economic considerations. It is also the case that many individual safety measures

will have impact on a variety of problems. The interactions between remedies and problems are numerous and com-

plex. The following are a few illustrations of the kinds of difficulties to be resolved in determining priorities for

alternative actions.

(i) Lower speed limits in rural areas may reduce the need for better surfaces to alleviate wet weather problems,

but observance of speed limits may be more difficult and costly to achieve than changes in surface texture.

(ii) Stricter drink/driving law enforcement may reduce the incidence of excess speed and loss of control of

vehicles, especially in the hours of darkness.

(iii) Within the area of road engineering alone there are alternatives of geometrical design or control, surface, signs

or markings, which may individually or in combination provide a satisfactory solution to junction conflicts.

(iv) The dark accident problem can be alleviated by any or all of: road surface texture, road lighting, clearer

definition of road alignment and obstacles (by reflectorisation, etc) and vehicle lighting.

(v) Increased seat belt wearing will alter the ratio of injury/non-injury accidents and may in consequence change

the priorities for dealing with different situations, eg roads with different speed limits, or accidents by day or

night, for which severity of injury differs.

Urban/rural/motorway situations often demand different priorities, eg pedestrian and cycle casualties

predominate in urban areas, While vehicle/vehicle conflicts predominate on rural roads leading to car

occupants being the most vulnerable road users.

These and many other interactions need to be examined when alternative options for future road safety

action are considered.

6. DISCUSSION OF RELATIVE RETURNS

With so many options available at a time when economic constraints are strict, it is vital to try to assess relative

costs of implementation and likely returns. Many of the individual options have been costed and in particular there

is ample evidence in the road engineering field of substantial economic benefit, even on the basis o f first year returns

only. An attempt will now be made to examine the issues more broadly in terms of how to achieve value for money.

The options in road engineering which have been taken into account here relate only to low cost remedial

measures, excluding any consideration of new road works. They include dealing with 'hazardous road locations' 11

in the broadest sense, encompassing the conventional blackspot approach for specific sites, mass action plans which

cover application of particular remedies, route schemes and area approach to application of measures 12. While all

four techniques apply low cost measures, which individually cost only a few thousand pounds, in total they will

become more costly with fewer returns as the number of measures applied and the area covered increase. Thus

9

individual blackspots may be treated for a cost o f a few thousand pounds and give a first year ERR (economic

rate of return) of up to 400 per cent. However a more realistic figure over a local authority area is to expect on

average a first year ERR of 50 per cent.

The area approach to application of countermeasures recently suggested by the Transport and Road Research

Laboratory aims at developing comprehensive methods o f treating urban areas, and has particular relevance to

pedestrian safety. It is regarded as an extension of site-specific techniques, not a substitute for them. In principle

the approach is to select low cost remedial measures on the basis of needs identified by dominant factors in accidents

but not site-specific, and to apply them on a linear or area basis according to criteria relating to traffic, layout and

land use. The need for this approach is illustrated by comparison of the different types of road user casualties which

occur in accident clusters on the main distributor system of roads with those scattered in residential areas: as an

example taken f rom one town under study (Swindon), 40 per cent of casualties occurring in clusters on the main

network are vehicle occupants and only 18 per cent pedestrians, while 43 per cent o f casualties scattered diffusely

over residential streets are pedestrians. Application of site-specific measures alone would preclude any saving to this

particularly vulnerable group of road users in residential areas.

A number of independent studies 13'14 have agreed on the same orders of magnitude of the critical parameters

determining benefits f rom small road improvements applied at specific locations, ie "blackspot treatment ' . In broad

terms:

(i) approximately one-third of all accidents occur in clusters;

(ii) on average a one-third reduction in accidents may be expected from treatment of such locations;

(iii) adiscounted benefit-cost ratio of 4 to 1 may be expected on average (approximately equivalent to a ftrst year

rate of return o f 50 per cent).

Applied nationwide this represents a saving of one-ninth of accidents - 30 000 injury accidents representing

£120 million pa. The cost of measures to achieve this would be of the order of £30 million, and the saving from

site-specific (blackspot) treatment would account for roughly one-half of the potential suggested in Table 7. The

other half will come f rom mass action and area application of low cost measures. For these it has been suggested

that the first year rate of return is o f the order of 25 per cent, so to cover action nationwide the resources required

would be of the order of £60 million. In round figures an expenditure of £100 million in a comprehensive low

cost road engineering improvement programme, spread over a number of years, would produce a return o f £250

million from accident savings.

In assessing benefits from vehicle engineering measures, a more complex and long term appraisal is necessary to

assess the f'mancial benefits from savings in accidents or injuries. Unlike road engineering measures which can be

localised, any worthwhile vehicle measure must be applied to a whole population of vehicles (14 million cars,

1.2 million motorcycles, etc) and unit costs have to be multiplied accordingly. Full implementation may not reach

the majority of the target group of vehicles for 10 to 15 years. Moore 15 has suggested a basis for assessing the cost

o f accidents in which the average car is involved in its 10 year life span, against which may be equated the cost of

equipment or improvement to the vehicle. Updating his work to 1977 gives a figure of £705 for the cost o f accidents

in which the average car is involved. Discounting this figure at 7 per cent over 10 years indicates that it would be

worthwhile spending £578 on a new car if all car involvements could be eliminated (highly unlikely) or proportionately

10

less to achieve smaller savings in accidents: for example, £29 per car if 5 per cent o f all car involvements could be

saved. Similarly, calculations for motorcycles, with an average life o f 8 years, give an overall figure o f £56 for

the worthwhile spend per motorcycle to save 5 per cent of motorcycle involvements.

Such considerations relate to features like anti-lock brakes and safety tyres, and new design features for

vehicle occupant protection. Measures to increase seat belt wearing however illustrate how different options may

be used to achieve the same end point, at different economic or social costs. Accepting, as is now widely the case,

that seat belts (or restraints in the broadest sense) are highly effective in reducing injuries, the wearing of belts

(or adoption of restraints) may be achieved in three main ways: persuasion, compulsion by legislation, and

engineering alternatives of passive restraints (seat belts, chest pads, or air bags). There is objective evidence of the

measure of success of each option; examples can readily be cited. In Britain persuasion through the Department of

Transport's publicity campaigns has cost between £½ million and £1 million per year since 1973: over that period

the wearing was initially doubled to around 30 per cent and maintained at that level for seven years. The estimated

savings in that time are about 5000 deaths and serious injuries per year, equivalent to £25 million pa. In Australia,

enforcement of wearing seat belts by legislation has reduced deaths and injuries by between 20 and 40 per cent

overall for car occupants 16, representing in equivalent British costs between £70 million and £150 million pa.

The cost of enforcement is not known but the extra enforcement required is reported to be minimal. In the

United States 17, trials of passive restraints have reported nearly 70 per cent reduction in deaths in Volkswagen

Rabbits equipped with passive seat belts and 50 per cent reduction in death rates in General Motors models equipped

with air bags. In this area it is suggested that future developments in measures to increase belt wearing may be

significantly affected by attitudes of road users to risk in relation to social considerations and personal choice - an

aspect which will not be considered here, but one which will increasingly need to be taken into account in all fields

of remedial action for safety.

In reducing the numbers of accidents, influencing human behaviour is paramount: this is the most difficult

area in which to effect safety measures but when achieved the results can also be the most dramatic. Two major

examples are: the effect of the introduction of the legal limit of 80mg/100ml alcohol in the blood of drivers in

196718, which resulted in a reduction of 11 per cent in the national casualty toll; and the effect o f the onset of

the fuel shortage and all its associated factors in late 1973, resulting in an initial reduction of 8 per cent of the

national casualty toll. In each case the initial benefits were not maintained, nor have the reasons for the change in

behaviour of drivers on either occasion been entirely understood. A thorough and worldwide appraisal of drink/

driving legislation 19 suggests that there are three necessary requirements to achieve change in behaviour: simple

procedures acceptable to police and public, a high risk of apprehension (whether actual or perceived), and wide and

continuing publicity of the adverse effects of drinking and driving. These aspects are discussed further in

Dr Raffle's paper 20. In terms of value for money, the estimated benefits from revitalised action (legislation

combined with publicity), on the basis of an anticipated 10 per cent saving in accidents, are of the order of

£150 million a year at current prices; this also represents a saving of at least 100 000 hospital bed-nights per annum.

Costs of implementation of new legislation and enhanced publicity have not yet been published, but even if they

were of the order of £10 million per year the economic returns would be of the order o f 10 to 1.

Benefits from other behavioural options for remedial action are much more difficult to quantify, though there

are examples of good economic returns in some areas on some occasions. Campaigns to encourage seat belt wearing,

already mentioned, have given returns of at least 20 to 1, although other campaigns have had less certain results or

11

been less successful. Where speed limits have resulted in reduction in speeds, reductions in accidents between 10 per

cent and 20 per cent have been achieved; costs of extra enforcement required have not generally been evaluated.

Police presence has considerable effect on behaviour and accident occurrence, as is instanced by one example 21 of

enforcing speed limits over an area which produced economic returns of 2 to 1. The potential saving in accidents is

more than is suggested by the 'up to 5 per cent' in Table 7, but this ftgure is based on the assumption that resources

are limited and benefits are likely to accrue only from redeployment rather than an increase in manpower directed

to traffic duties.

The most uncertain area in quantification of benefits is that of education and training, and yet this may be

the key to long term reduction in accidents and casualties. It is the very fact that results are long term that makes

evaluation o f remedial measures difficult - and in terms of accident savings almost impossible. The evidence to show

the benefit o f driver training (car or motorcycle) for the ordinary motorist in terms of accident savings is disappointing.

But most of the driver training is short term and it has been suggested 22 that such training may generate overconfidence.

One should not condemn driver training because of the apparent lack of success of present driver training methods,

but rather look to ways of enhancing the training. The real dilemma is how to acquire the benefits of experience

gained over thousands of miles of travel without the adverse consequences of being in traffic, resulting in accidents.

To gain long term benefits of changes in behaviour, it seems logical to assume that a long term approach to education

and training must be adopted - and pursued as an act of faith. To this end the greatest promise lies in education and

training from the earliest age as an integrated part o f the school curriculum. The teaching manuals 'Children and

Traffic '23 illustrate the principle of successively dealing with the road situations a growing child meets: 'on the

pavement' for the 5 - 7 year olds; ' the young traveller' between 7 and 9 years; 'preparing for the road' between 9

and 13 years old.

Consideration of the role of education and training in road safety re-opens the question of how values should

be assessed. There is a dilemma in applying the conventional costing procedures used here for assessment of long

term measures. Economic benefits evaluated in this way are unlikely to be positive (even if they are capable of

evaluation) and certainly will not compare with those from engineering measures. Other long term schemes such

as afforestation and general education are determined on less precise criteria. Current concern to get value for

money - a very real and urgent need - should not nevertheless cloud the broader issues which will have

repercussions on future generations.

7. LOCAL AUTHORITY PRIORITIES

In looking to priorities for action to reduce the road accident toll, a balance between short and long term returns

needs to be made. In terms o f the measures which lie within the compass of the responsibility of the Local

Authorities, the short term benefits wiU undoubtedly come from application of low cost road engineering measures.

Education, training and publicity have their place in support of engineering measures now, but, in the long term

they will assume even greater importance. The road engineering programme may be considered in terms of a five to

ten year programme of work, and although there will be a continuing need to monitor the requirement for application

o f low cost measures, further impact beyond that period will depend on developing a sound educational programme

in the broadest sense. In this respect there is an urgent need to advance the understanding of appropriate measures

to influence road user behaviour: to achieve this a necessary task will be to explore public attitudes to road safety

or the safety expectations that people have of the road system. There may be regrets in the next decade if these

behavioural aspects are not pursued.

12

Within the engineering programme, where knowledge of appropriate remedial measures is so much more

advanced, economic values have been placed on the returns from money spent. In doing this it must be stressed

again that absolute levels are subject to the uncertainties associated with costing o f the various consequences of

road accidents. Nevertheless, the accepted economic cost of accidents is a valid tool to assess priorities within the

engineering field. The current widespread practice of applying low cost remedial measures at hazardous road

locations can be advanced by improving techniques of application and extending them beyond the conventional

'blackspot' approach, through development of mass action plans, to the area approach to urban situations, which the

Transport and Road Research Laboratory in conjunction with a number of local authorities is hoping to demonstrate

in the near future. The resources required for dealing with hazardous road locations are low compared with the

potential benefits or with general road building costs, so the prospects for reduction of the full potential of one,fifth

savings in accidents which has been suggested are high.

In conclusion it is worthwhile recalling what has been achieved in road safety so far. The year 1965 was a turning

point: since then accidents have been contained by various education, enforcement, and engineering measures,

although trends (Table 8 and Figure 1) have also been influenced by environmental factors beyond the control of

road safety workers. Road safety measures currently cost about £1000 million per annum - a sum comparable in

scale to the cost of accidents themselves. This figure puts in perspective the additional resources required to effect

some of the measures suggested in this report. Future trends will depend, not just on resources made available, but

on the optimum choice of application of those resources.

8. ACKNOWLEDGEMENTS

The work described in this report forms part of the programme of the Transport and Road Research Laboratory

and the report is published by permission of the Director.

9. REFERENCES

. DEPARTMENT OF TRANSPORT. Road accident costs 1977. Highways Economics Note No. 1 (September

1978).

. LEITCH, Ge t al. Report of the Advisory Committee on Trunk Road Assessment, pages 103-5 . London,

1977 (H M Stationery Office).

. SABEY, B E and G C STAUGHTON. Interacting roles of road environment, vehicle, and road user in accidents.

Paper presented to the 5th International Conference of the International Association for Accident and Traffic

Medicine, London, 1975.

4. DEPARTMENT OF TRANSPORT, SCOTTISH DEVELOPMENT DEPARTMENT, WELSH OFFICE.

Road Accidents Great Britain 1977. London, 1978 (H M Stationery Office).

. GARWOOD, F. Some applications of statistics in road safety research. Paper presented to Manchester

Statistical Society, 1956.

13

TABLE 8

Trends in injury accidents and casualties

1949 1950

1951 1952 1953 1954 1955

1956 1957 1958 1959 1960

1961 1962 1963 1964 1965

1966 1967 1968 1969 1970

1971 1972 1973 1974 1975

1976 1977

Traffic index of vehicle km 1949 = 100

100 114

127 131 139 150 165

174 173 200 224 242

263 276 293 328 350

380 398 417 427 451

481 505 532 517 526

548 567

Injury accidents

(thousands)

147 167

178 172 186 196 217

216 219 237 261 272

270 264 272 292 299

292 277 264 262 267

259 265 262 244 246

259 266

KiUed

4773 5012

5250 4706 5090 5010 5526

5367 5550 5970 6520 6970

6908 6709 6922 7820 7952

7985 7319 6810 7365 7499

7699 7763 7406 6876 6366

6570 6614

Castmlties

Seriously injured

(thousands)

43 49

52 50 57 57 62

61 64 69 81 84

85 84 88 95 98

100 94 89 91 93

91 91 89 82 77

80 82

14

. JOHNSON, N L and F GARWOOD. An analysis of the claim records of a motor insurance company.

Journ. Inst. Actuaries, Vol 83, Part III, No. 365, December 1957.

7. MUNDEN, J M. Some analyses of car insurance claim rates. Astin Bulletin, Vol II, Part II, September 1962.

. STORIE, V J. Male and female car drivers: differences observed in accidents. Department of the Environment

Department of Transport, TRRL Report LR 761. Crowthorne, 1977 (Transport and Road Research

Laboratory).

. SABEY, B E. Potential for accident and injury reduction in road accidents. Paper presented to the Traffic

Safety Research Seminar organized by the Road Traffic Safety Research Council of New Zealand, Wellington,

New Zealand, 1976.

10. SABEY, B E and H TAYLOR. The known risks we run: the highway. Paper presented to the General

Motors Research Symposium on Societal risk assessment: how safe is safe enough? Warren, Michigan,

October 1979.

11. ANON. Hazardous road locations: identification and countermeasures. Report of an OECD Road Research

Study Group, Paris, 1976.

12. DALBY, E. The use of area-wide measures in urban road safety. Paper presented to Traffex '79 Conference

on Traffic Engineering and Road Safety. Brighton, 1979.

13. DEPARTMENT OF THE ENVIRONMENT. Duty of local authorities to promote road safety. Circular

Roads 12/75.

14. LEEMING, J J. Before and after studies of road accidents. Journ. Inst. Highway Engineers, February 1968.

15. MOORE, R L. Methods of determining priorities in a programme of research. IEEE Transactions on

Engineering Management, Vol EM-21, No. 4 USA, 1974.

16. GRIME, G. The protection afforded by seat belts. Department of the Environment Department of

Transport, TRRL Report SR 449. Crowthorne, 1979 (Transport and Road Research Laboratory).

17. ANON. US Department of Transportation News. DOT 12278, Washington DC, August 1978.

18. SABEY, B E. A review of drinking and drug-taking in Great Britain. Paper presented to the 7th International

Association for Accident and Traffic Medicine, Ann Arbor, Michigan, 1978. Transport and Road Research

Laboratory, Supplementary Report 441, Crowthorne, 1978.

19. ANON. The role of alcohol and drugs in road accidents. Report of an OECD Road Research Study Group,

Paris, 1978.

15

20. RAFFLE, P A B. Medical aspects of road safety. Paper presented to Road Safety Seminar, Inst. Munic. Engrs,

October 1979.

21. MUNDEN, JM. An experiment in enforcing the 30 mile/h speed limit. Ministry of Transport, RRLReport

LR 24. Harmondsworth, 1966 (Road Research Laboratory).

22. DEPARTMENT OF TRANSPORT. Road safety education, training and policy. A Conference on Road

Safety, London, 1978.

23. JOLLY, K. Children and traffic. Macmillan Education, 1977.

16

X Q.)

"O r -

o_

°--

I -

500

4 0 0

3 0 0

2 0 0

100

m

/ . / " \ J - - . __ / . , - - - / - - - X

f ~

/

I I I I I I I 1 9 5 0 1 9 5 5 1 9 6 0 1 9 6 5 1 9 7 0 1 9 7 5 1 9 8 0

- - 1 2 0

- - 1 0 0

- - 8 0

- - 6 0

-- 4 0

- - 2 0

0

A r,~

" O C

O

"2' o_

O o-- =..

. . f .

¢o

U .

Fig. 1 T R E N D S I N R O A D T R A F F I C A N D C A S U A L T I E S

Printed for Her Majesty 's Stationery Off ice by Hobbs the Printers o f Sou thampton

(2820/86) Dd8222685 CI 10/86 G426

ABSTRACT

ROAD SAFETY AND VALUE FOR MONEY: Barbara E Sabey BSc FlnstP FIHE: Department of the Environment Department of Transport, TRRL Supplementary Report 581 : Crowthorne, 1980 (Transport and Road Research Laboratory). The current state of knowledge on factors which may aid decisions to achieve value for money in road safety is outlined. The discussion includes consideration of the monetary value placed on road accidents, and the options for remedial action in the fields of road engineering, vehicle design and usage, and human behaviour.

Assessments are made of the relative costs of implementation of, and likely returns from, different remedial options. It is concluded that in seeking priorities for action to reduce the road accident toll, a balance between short and long term returns needs to be made. Where Local Authorities are concerned, the short term benefits will undoubtedly come from application of low cost road engineering measures. Education, training and publicity have their place in support of engineering measures, and will assume even greater importance in the long term.

ISSN 0305-1315

ABSTRACT

ROAD SAFETY AND VALUE FOR MONEY: Barbara ESabey BSc FlnstP FIHE: Department o f the Environment Department of Transport, TRRL Supplementary Report 581: Crowthorne, 1980 (Transport and Road Research Laboratory). The current state of knowledge on factors which may aid decisions to achieve value for money in road safety is outlined. The discussion includes consideration of the monetary value placed on road accidents, and the options for remedial action in the fields of road engineering, vehicle design and usage, and human behaviour.

Assessments are made of the relative costs of implementation of, and likely returns from, different remedial options. It is concluded that in seeking priorities for action to reduce the road accident toll, a balance between short and long term returns needs to be made. Where Local Authorities are concerned, the short term benefits will undoubtedly come from application of low cost road engineering measures. Education, training and publicity have their place in support of engineering measures, and will assume even greater importance in the long term.

ISSN 0305-1315