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Road safety audit is a formal procedure for independent assessment of the accident potential and likely safety performance of a specific design for a road or traffic scheme - whether new construction or an alteration to an existing road.

Road safety impact assessment is a formal procedure for independent assessment of the likely effects of proposed road or traffic schemes, or indeed other schemes that have substantial effects on road traffic, upon accident occurrence throughout the road network upon which traffic conditions may be affected by the schemes.

These two procedures enable the skills of road safety engineering and accident analysis to be used for the prevention of accidents on new or modified roads. They thus complement the use of these same skills to reduce the occurrence of accidents on existing roads by means of local safety schemes, in many cases in the form of low-cost measures (ETSC, 1996).

This review aims to describe and illustrate the use of safety audits and safety impact assessment in helping to design and build safe road and traffic schemes, and at the planning stage in choosing which schemes to progress from among a range of possibilities.

Both procedures have strong contributions to make to rational and effective decision-making when considering alternative options, and safety audit is important to the achievement of a safe design for a chosen alternative. The two procedures are complementary - the aim is similar and the difference is in scope and timing.

The scope of safety audit is usually confined to an individual road scheme, which may be a new road or modification to an existing road. The basis for safety audit is the application of safety principles to the design of a new or a modified road section to prevent future accidents occurring or to reduce their severity. The procedure is usually carried out at some or all of five stages in carrying out a scheme: feasibility study, draft design, detailed design, pre-opening and a few months after opening. An essential element of the process is that it is carried out independently of the design team. It should be undertaken by a team of people who have experience and up-to-date expertise in road safety engineering and accident investigation.

The scope of safety impact assessment is dependent on the scale of the schemes being considered. For small-scale schemes, the impact of change can usually be expected to be confined largely within the scheme itself. In this situation safety impact assessment and safety audit share many procedural characteristics. For larger schemes, the impact on accident occurrence can be expected to be felt over a larger part of the road network. In that case, the impact may be estimated using a scenario technique. By considering different road types, the corresponding values of relevant safety indicators and the forecast traffic volumes, the impact on accident occurrence can be estimated for different alternatives.

The development of safety audit for road and traffic schemes, and especially the fifth stage of monitoring the operation of such schemes after they have been open to traffic for some months, raises the question of the role of safety audit or analogous safety checking in respect of existing roads. There is a prima facie case that an independent assessment of conditions on an existing road would be likely to reveal deficiencies indicating scope for cost-effective measures for accident prevention additional to the accident remedial measures that are routinely identified by investigation of accident occurrence.

The benefits of safety audits and safety impact assessment are in:

Well-documented experience in Europe and elsewhere shows that formal systematic safety audit procedures are a demonstrably effective and cost-beneficial tool to improve road safety. But they are used so far by only a minority of Member States. ETSC believes that sufficient information is available to warrant the EU and Member States taking a series of measures leading to routine application of safety audit procedures to schemes for new road construction and modification of existing roads in order to realise the full contribution that road infrastructure schemes can make to casualty reduction. Consideration should also be given to systematic safety checking of existing roads to complement accident investigation work.

Safety impact assessment procedures are not yet carried out anywhere on a national basis, although there has been some initial experience in The Netherlands and some aspects of safety impact assessment are included in appraisal procedures in some other Member States. Some Member States, however, have valuable experience in safety auditing techniques for road infrastructure projects and for these, the next step is to take a more strategic approach by looking at safety effects on the wider road network by means of safety impact assessment. There is also an important role for the EU in encouraging work in this area.

In urging action by Member States, ETSC wishes to emphasise that although the procedures of safety audit and safety impact assessment are complementary, neither is dependent upon the other. Early action to implement safety audit can therefore go ahead and be yielding benefits whilst work proceeds on the lengthier task of establishing procedures for safety impact assessment.

In relation to safety audit ETSC recommends that Member States should:

(a) examine their own procedures for the assessment of safety in road infrastructure projects to see how they can be made more effective in the light of practice in other Member States;

(b) where no formal procedure for safety audit exists, introduce a mandatory requirement that all major new road schemes be subjected to an independent safety audit;

(c) in time, extend formal procedures to smaller schemes and the safety checking of existing roads;

(d) prepare guidelines for use at national and local level laying down the terms of reference for safety audit including the roles and responsibilities of all concerned, with the help of experience in countries where safety audit is already practised;

(e) prepare a detailed manual of good practice which may be used in conjunction with the guidelines;

(f) send technically trained road safety professionals and their managers to learn at first hand from their counterparts in other Member States about their application of safety audit, and be ready to receive such visiting professionals from other Member States; and

(g) reconsider their allocation of trained staff and finance within their highway budgets to application of safety audit in the light of the benefit to cost ratios that it offers.

Regional and local authorities should:

be ready to share their experience of applying safety audit procedures with their counterparts in other Member States and to learn from them in return, especially by contributing to and drawing upon the EU's documentation of best practice and by exchange of visits by road safety engineers and managers.

In relation to safety impact assessment, ETSC recommends that Member States should:

(a) consider to what extent their existing arrangements for the appraisal of transport infrastructure projects take account of the likely impact of each project on accident occurrence throughout the affected road network;

(b) enhance their procedures for such appraisal so that they include all aspects of safety impact assessment.

Any new scheme on the TERN will, at the stage of feasibility study, be subject to mandatory Environmental Impact Assessment (EEC, 1985). ETSC believes that they should in a comparable way be subject to safety impact assessment covering the likely effects on accident occurrence, injury and damage not only on the relevant section of the TERN itself but also on all local roads on which traffic will be affected by the scheme. ETSC therefore welcomes the Commission's stated intention in its new action programme (CEC, 1997) to prepare new guidelines on safety impact assessment which would be applied in a first stage to the TERN and other EU financed projects.

The chosen scheme that emerges from the feasibility study should then be subject to safety audit at the stages of preliminary design and detailed design, and on site just before opening to traffic and after several months of operation.

In the context of its responsibility for transport safety, the EU can add value to the efforts of the Member States by acting to accelerate the rate at which citizens of the EU can benefit from more widespread and effective use of safety audits within each Member State.

Further steps by the EU which ETSC believes would be useful are as follows:

(a) as a first step promote international best practice by producing technical guidelines on safety audit;

(b) as a second step introduce an EU Directive requiring that all major new road schemes be subject to an independent safety audit;

(c) establish a European network of training in safety audit for road safety professionals and managers;

(d) encourage the transnational mobility of technically trained road safety professionals and their managers to accelerate the transfer among Member States of successful techniques and procedures for applying safety audits; and

(e) look for mechanisms by which its own allocation of funds to Member States for investment in roads can be used to encourage the recipient states to allocate funding within their highway budgets to programmes of safety audit.

ETSC believes that the promotion of safety impact assessment through the establishment of guidelines for the TERN and all EU funded projects would be a helpful first stage in integrating safety considerations into the relevant decision-making processes.

As a second stage, ETSC recommends that a mandatory requirement for safety impact assessment covering all new transport infrastructure projects should exist alongside EU procedures for environmental impact assessment with immediate application to the TERN and subsequent application to all transport infrastructure projects in all Member States.

Eventually, safety impact assessment should extend to all land use planning decisions as is envisaged for the developing environmental impact assessment.

Acknowledgements

ETSC gratefully acknowledges the contributions of members of ETSC's Road Infrastructure Working Party to this review and, in particular, the work of Professor Richard Allsop, Chairman of the Working Party and editor of the review.

Prof. Richard Allsop (Chairman)
Prof. Werner Brilon
Mr Finbarr Crowley
Mr Dominique Fleury
Prof. Siegfried Giesa
Dr Lene Herrstedt
Prof. António Lemonde de Macedo
Mr Geoff Maycock
Prof. Jef Mortelmans
Dr Aristoteles Naniopoulos
Mr Fred Wegman
Prof. Aniceto Zaragoza
Mrs Ingrid van Schagen (WP Secretary)

ETSC is grateful for the financial support provided by DGVII of the European Commission and for the contribution towards the printing and dissemination costs of this review provided by 3M Europe, Ford Europe, BP, KeyMed and KLM Royal Dutch Airlines. The contents of this review are the sole responsibility of ETSC and do not necessarily reflect the view of sponsors nor organisations to which research staff participating in the Working Party belong.