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Safety governance of complex highway projectsAbstract

This paper describes the use of Project Safety Risk Management Systems in defined highway situations where the relationships between design and future operation require robust management. In particular the use on Managed Motorway type schemes is described.

In the UK it is now becoming common practice to adopt a Project Safety Risk Management System in defined highway situations where the relationships between design and future operation require robust management.

Clients are increasingly supportive of the need to embed safety culture in all aspects of their projects and understand that the traditional incremental approach (such as design followed by audit) may not be sufficiently robust. In particular it is recognised that many schemes do not have the luxury of being developed against a tried and tested set of design standards.

The Highways Agency has developed interim guidance on the use of Project

Safety Risk Management Systems and this is due to be published as Interim Advice Note Number 139. This advice has been developed from other industries such as rail and aviation but adapted and developed for use on highway schemes where the biggest ‘variable’ is the public road user. Its first use on a highway scheme was the M42 Active Traffic Management pilot in the West Midlands. Use of the technique has now grown to the Managed Motorway programme and other innovative schemes.

Figure 1 shows the main components of the system.

Introduction

Peter WhitfieldPrincipal Consultant

Highways & Transportation

Atkins

PROJECT SAFETY RISK MANAGEMENT

SAFETY PLAN

Safety Objectives

Safety Baseline

HAZARD LOG

Safety Challenges

Operations & Maintenance

Issues

SafetyTasks

Operations & Maintenance Documents

SAFETY REPORT

Safety Requirements

Verification Activity

Figure 1. Components of Project Safety Risk Management System

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Component partsThe purpose of each stage is outlined as follows:

Safety planThis important document sets out for a client how the safety management process will be organised covering the following issues:

• Agreement of key staff and their competencies;

• Arrangements for project safety committees, stakeholder liaison and any workshops;

• Identification of data, documentation and published standards for design, safety and operations;

• Identification of key safety challenges ahead based on known existing safety problems or perceived risks associated with innovative proposals;

• Definition of safety baseline (typically existing accident frequencies) against which the project safety targets will be measured post-opening;

• Definition of safety objectives, both numerical and non-numerical, for the opened project and any overarching programme or client safety initiatives;

• Agreement of suitable methods for risk assessment (Hazard log);

• Links to other processes such as Road Safety Audit, Maintenance Strategy etc.;

• Links to any “micro” safety cases for the design of telematics.

Any scheme that is associated with complex operational regimes is likely to require significant consideration of future risks to road workers, emergency services and civilian traffic officers. Therefore the Safety Plan should set out appropriate safety objectives for these users as well as public users.

Hazard logDepending on the type of project and its level of similarity to other completed infrastructure projects already in operation it is necessary to:

• Develop a bespoke hazard log; or

• Amend an existing generic hazard log (one published by the Highways Agency).

The total risk to road users within the completed project can be considered as “RTOTAL(AFTER)” and this is made up of individual risk components from hazards H1, H2, H3 etc.. Using this approach, as shown in Figure 2, it becomes easy to

understand where the main problems may arise and where the design effort should be focussed.

The relative widths of the bars in Figure 2 represent the relative importance of each hazard. The risk score for each individual hazard takes account of:

• Frequency of incidents that may lead to harm;

• Probability of such incidents subsequently giving rise to harm;

• Severity of any injuries that may result.

The assessment considers RTOTAL(AFTER) and RTOTAL(BEFORE) and it is therefore possible to predict ahead of scheme opening if the safety objective can be met. For example in broad terms if a scheme has a safety objective of reducing accidents by 15% then the hazard log would need to predict at least a 15% risk reduction as measured by the difference between RTOTAL(AFTER) and RTOTAL(BEFORE).

The prevalence of a large number of small bands to the right of Figure 2 is also useful in demonstrating that many issues are in fact low safety risks. This is very useful in responding to potential issues that are perceived by stakeholders to be initially significant.

As with any risk assessment the process is useful in developing a thorough understanding of accident modes and in turn this leads to the generation of mitigation measures to control the risk by attempting to break the casual chain associated with the accident mode. For example in the case of a hard shoulder running scheme, the risk of a stationary vehicle on the hard shoulder is reduced by providing emergency refuge areas and also by carrying out a systematic CCTV

camera by camera review before opening the hard shoulder to traffic at a reduced mandatory speed limit.

This process leads to the development of a list of essential inclusions and prohibitions for both the infrastructure design and operating protocols. These are termed “Safety Requirements”.

Safety report (safety case)This document is normally produced at more than one stage dependant on the scale of the project. For large projects it would be normal to produce it at the end of the design stage, pre-opening and post-opening. It describes:

• The forecast (or actual) safety performance of the scheme against safety targets;

• The Safety Requirements related to the infrastructure design or operating protocols that are intrinsically linked to the good safety performance of the project;

• How verification (audit) of Safety Requirements will (or has) taken place to ensure compliance;

• Any residual actions and safety monitoring;

• Information storage requirements.

Process versus cultureThe use of a Project Safety Risk Management System should not be considered as merely a mechanical process. The use of this technique gives rise to a number of other benefits:

• It embeds safety in decision making, without dictating that safety should be the only concern;

Figure 2. Example of before and after risk scores associated with individual hazards

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• It allows prudent judgement to be applied to a number of design options;

• It allows stakeholders to understand issues that may affect them;

• It allows participants to challenge the “common wisdom” and standards;

• It drives cross discipline working and is therefore “lean” in its approach.

Decision makingThe project Safety Plan (see above) should set out how a project makes decisions. It is normal to set up a Project Safety Risk Control Group with representation from maintainers, stakeholders and client representatives from different backgrounds. Such a group can add value to decision making whilst ensuring that safety related issues are balanced against other scheme objectives.

Experience to dateAtkins has worked on a number of projects using this methodology. These include:

• M62 J25 to J30 Managed Motorway, Highways Agency (design stage);

• M4/M5 Managed Motorway Scheme, Highways Agency (design stage);

• M6 Junctions 10a to 13 Managed Motorway Scheme, Highways Agency (feasibility stage);

• M4 Variable Mandatory Speed Limits Newport, Traffic Wales/Welsh Assembly Government (controlled motorway now open to traffic);

• Research into feasible options to improve motorway to motorway traffic flows using traffic signals.

In the case of the M4 Variable Mandatory Speed Limits (Controlled Motorway) project between J24 and J28, Figures 3 and 4 show the novel use of verge signals that can rotate through ninety degrees and can be wound down to ground level. This allows maintenance to be carried out with minimal effect on traffic lanes and also reduced risks to operatives.

Although the implementation of a Controlled Motorway by use of lane dedicated message signs (as shown on the portal gantry in Figure 5) follows the practice of earlier Controlled Motorway schemes, Figure 5 also shows that the project utilised existing variable message signs in the verge and on both new and existing portal gantries. The operational use of combinations of signals, both day to day and during incidents, was a particular challenge to ensure that the algorithms did not lead to confusing message sequences.

Does this replace road safety audit?This technique complements road safety audit but does not replace it. Whilst it is possible to adopt a level of independence from design teams when using Project Safety Risk Management Systems, this is not necessarily desirable as understanding and influencing safety risk is linked to influencing the design and operating protocols from project inception. This also means that using an independent road safety audit team is still beneficial and in any case is still required by standards

(HD19/03)1. As with all road safety audits, the quality of the audit is dependent on the knowledge and skills of the personnel and the brief set down. Atkins has found it useful to ensure that the audit team is aware of the hazard log and also ensured that the audit team is familiar with the operational aspect of the scheme genre. It is also noted that the hazard log results have been helpful in qualifying a designer’s response after a road safety auditor has identified risks without quantification. Road safety auditors are likely to possess the skills to assist with the generation of scheme hazard

Figure 3. Verge signal rotated to operational position (M4 Newport)

Figure 4. Verge signal rotated away from carriageway to facilitate maintenance (M4 Newport)

Figure 5. Combination of existing variable message signs in verge and on gantries (M4 Newport)

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logs and consideration should be given to their use in this way, although any individual involved in production of risk assessment would normally not go on to play a part in the subsequent road safety audit due to the issue of independence.

Future use of these techniquesThis technique is highly adaptable to a range of project sizes and types. As with all risk assessment techniques it should be used appropriately for the circumstances. It is envisaged that the process could be

usefully adopted for large scale urban event management and for schemes with a high level of operating interfaces, such as public transport interchanges and on-street mass transit.

As well as informing funded infrastructure projects the technique is very useful in developing strategic policy interventions so that safety impacts can be estimated whilst developing strategies. Examples may include tolled lanes, pedestrian guardrail provision or setting levels of maintenance intervention.

ConclusionSafety should be at the core of all projects and suitable systems to understand where risks might lie are likely to be of substantial benefit. Unwarranted and unquantified safety concerns have in the past been a potential barrier to innovation. Good governance of safety management from the earliest days of project inception can be a useful aid to informed decision making and promotion of suitable project options.

AcknowledgmentThis paper was published in an abridged article form in Local Transport Today Issue 570 - 6 May 2011: Road Safety Supplement

References1. Design Manual for Roads and Bridges Volume 5 Section 2 Part 2 HD 19/03 Road Safety Audit