p_road safety audit chap 15

8/12/2019 P_Road Safety Audit Chap 15

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Road Safety Audit

Hossein Naraghi

CE 590 Special Topics

Safety

June 2003

Time spent:9 hrs


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Road Safety Audit

A complementary action to accidentreduction is accident prevention

The aim is to ensure that the road systemis safe

One of the key component of accidentprevention involves the use of safetychecks or safety audits

The focus is on the design of new road andtraffic schemes

Sometimes the focus is on the existing roadway


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Definition and objectives ofroad safety audit (continued)

The Roads and Traffic Authority ofNew South Wales describe safety

audit asA means of checking the design,

implementation and operation of roadprojects against a set of safety principlesas a means of accident prevention andtreatment


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Essential elements

The essential elements of the roadsafety audit process are

A formal process and not an informalcheck

An independent process

Carried out by someone with appropriateexperience and training

Restricted to road safety issues


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Safety audit objectives

The objective of the road safety audit is to

Minimize the risk and severity of roadaccidents that might be affected by theroad project at the site or nearby network

Minimize the need for remedial work afterconstruction

Reduce the whole-life costs of the project Improve the awareness of the safe design

practices by all of those involved in theplanning, design, construction and

maintenance of roads


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Safety audit objectives(continued)

Road safety audit can work in two ways:

1. Removing preventable crash producingelements at the planning or design stage e.g. inappropriate intersection layouts

2. Mitigating the effects of remaining orexisting problems

Inclusion of suitable accident reducingfeatures Anti-skid surfacing

Guard fencing

Traffic control devices

Delineation, and etc


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Safety audit objectives(continued)

Highway designers and traffic engineershave always practiced a form of safety audit

What is important about the recentemergence of the practice is

Its specific incorporation as a discrete phase

Independent of the designer

Development of defined auditing procedures

Followed within a road or traffic agency

May be incorporated within an overall qualitymanagement or quality assurance process within

the agency


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Use of road safety audit

The concept of road safety auditemerged initially in Britain in 1980s

It was one of the key response to theGovernments target of reducing roadfatalities by one-third by the year 2000

It was given impetus by the preparation of

two key publications1. Road Safety Code of Good Practice

Local Authorities Association, 1989

2. Guidelines for the Safety Audits of Highways

Institution of Highways and Transportation, 1990


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Use of road safety audit(continued)

Road safety audit was made mandatory for allnational trunk roads and motorways in 1991

In the light of the success of British experiencesthe process has also adopted in

New Zealand began the safety audit process in1992

From 1993, safety audit was mandatory in 20 percentsample of State highway projects

A comprehensive road safety audit policy has beenprepared

The World Bank has begun to show an interest in

the safety audit subject in 1992


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Application of road safetyaudit

Road safety audit may be carried out at anyor all following stages

Stage 1: Feasibility

A safety audit can influence the scope of a project

route choice

selection of design standards

impact on existing road network route continuity

provisions of interchanges or intersections

access control

number of lanes

route terminals, stage development, etc


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Application of road safetyaudit (continued)

Stage 2: Draft design This audit stage is undertaken on completion

of a draft plan or a preliminary design.

Typical considerations include Horizontal and vertical alignment

Sightlines

Intersection layouts

Lane and shoulder width

Super elevation

Overtaking lanes

Provisions for parked and stationary vehicles

Provisions for bicyclists and pedestrians

Effects of departures from standards and guidelines

Safety during construction, etc


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Stage 3: Detailed design

This stage is on completion of detaileddesign, normally before preparation ofcontract documents, considerations include:

Line markings

Signing

Delineation

Lighting Intersection details

Clearance to roadside objects

Provision to road user groups with special requirements

Temporary traffic management and control duringconstruction


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Drainage

Roadside objects

Landscaping

Batters Guard fencing, etc

Stage 4: Pre-opening

Prior to opening of the road to traffic

The audit would involve driving, riding andwalking through the project to check theadequacy for the needs of all road users

Involve night-time inspection

Inspection of both wet and dry conditions


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It would consider similar issues raised in stage 2and 3, but with the view of assessing theiradequacy as actually constructed

Taking specific note of variations that might haveoccurred from the plans in the process ofconstruction

Stage 5: In-service

Systematic examination of sections of theexisting road network to assess the adequacyof the road, intersection, roadside, etc froman explicit safety viewpoint

This can have two applications


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Monitoring a new scheme after it is openedto traffic

i.e. in the weeks and months following the stage 4

audit Safety audit of an existing road network with

a view of identifying safety-relateddeficiencies

Although all 5 of the above stages canand have been used

In practice the first and last of these stagesare less common


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Safety audit process

The key requirements are

Management commitment Auditors are outsiders brought in to find things

wrong with their work Audit process brings specialists advice to the design

team

In relation to implementation of the safetymanagement system in the USA, Hall 1993 wasconcerned about

Other functional units may believe that the accomplishmentof their goals are threatened by the infringement of safetymanagement initiatives into their territory

Care should be taken throughout system implementation tomaintain an atmosphere of cooperation and mutual respectamong affected functional areas


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Safety audit process(continued)

An agreed road safety audit process

The process aim to reduce the whole life cost

of a scheme Although there will be cost of audit process, it

is worthwhile if offset against the potential forsavings elsewhere

The savings may be from Timely alteration to plans It is much cheaper to change a detail on a plan

than to replace or remove a feature once installed

Subsequent accident prevention

Reduction in the costs resulting from litigation


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An independent auditor or audit team

There must be a designated procedurefor acting upon the audit report

If a specialist team is used, one of threeprocedures can be followed

1. Prior agreement to accept safety audit

recommendations2. Assessment of the audit report by theclient

3. Assessment of the audit report by thedesigner


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An agency developing a road safety auditprocess will need to determine which of theseprocedures to follow, depending upon its own

expertise and the role of safety auditing within awider institutional framework such as qualitymanagement

No matter which procedure is adopted the

key factors are as follow The audit team must include specialistknowledge of road safety engineering

Safety audit findings should be formallydocumented and reported at each step of theaudit process


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A set of checklists

Use of checklists which show type of issues

and problems that can potentially arise at therelevant stage of the project

Checklists are a memory prompt

When using checklists, it is less likely to

overlook problems They can not be a substitute for expertise

One of the main benefits of checklists is thatdesigners can use that to audit themselves

before their work gets to the auditor


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Training and development of expertise

The size of the audit team depends on the size

and complexity of the project British experience says at the feasibility or

layout design stage, three-person team wouldbe suitable, Comprising

A road safety specialist with experience in crashinvestigation and safety engineering principles andpractice

A highway design engineer

A person with experience in safety audit, who is ableto generate discussion and assist in the procedure


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Monitoring and evaluation

Process of monitoring and evaluation

involves three aspectsProcedures, problem encountered, andeffectiveness of the system

Critical appraisal of the checklists and

their use

Evaluation of costs and resources byscheme type and stage


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Liability

The Australian guidelines include a chapteron legal issues, with following conclusion

No case involving a road safety audit has yetcome before a court

The legal implication must be speculative

The predictions are not guesswork, they are

based upon well established principles of tortlaw

Safety audit will create a safer roadenvironment


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Liability (continued)

A major objective of litigation is encouragesafety, therefore the use of safety audit willbe encouraged by the legal system

Roads can be made safe by different methods

Black spot treatment

Periodic inspection

Adoption of higher standards of engineeringpractice

Greater allocation of funds and road safety audits

It is for highway authorities to decide whichmix of these is best for a given project


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Audits of existing roads

A formal program of safety audit of existingroads can be an important component of theoverall audit process

The aim of this stage of audit is to identify anyexisting safety deficiency of design, layout, andstreet furniture which are not consistent withroads function

There should be consistency of standards

Many items may be related to maintenance of theroad, therefore the benefit of the safety auditprocess is to ensure that these items are placed

on the maintenance program


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Audit of developmentprojects

An extension of the road safety audit in somelocal authorities is to require thatdevelopment proposals be audited, thesemay include

A new commercial development which willgenerate traffic on an existing road

A residential development which involves streetconstruction

In a road safety audit context, these would needto be independently audited and a reportsubmitted as part of development application


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Audit of developmentprojects (continued)

Audit report of development projectsmay address

The safety impact of peak periodcongestion

The generation of pedestrians andbicyclists movements across existingroads

The safe provision of public transportation

Vehicular and pedestrian access to the site


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Audit of developmentprojects (continued)

Adequacy of parking provision from asafety viewpoint

Pedestrian-vehicle conflicts on andadjacent to the site

Type and layout of intersections and newroad alignments

Speeds within the site

visibility


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Effectiveness of road safety audit

Although safety audit is relatively a newtechnique, evidence is emerging that safetyaudit is a cost-effective safety measure

A formal requirement that a project be subjectedto a safety audit will very likely lead to improvedsafety

UK experience suggests that for individualschemes perhaps one-third of crashes have thepotential for removal by safety audit

It should be noted that the resources need to bedevoted to safety audit are in fact quite small


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Effectiveness of road safety audit(continued)

UK experience suggests that one safety auditor isrequired to cover an area experiencing 1000casualty crashes per year

Australian and New Zealand experience suggestthat safety audit adds 4% to road design costswithout consideration of whole life savings fromsafety audit

There have been some attempt to quantify the

benefits of safety audit One highway authority in Scotland, 1991 has estimated

that one-third of future accidents at road improvementsare preventable by audit, and that a one percent accidentsaving per year worth $1.5 million at resource of

$100,000, a benefit:cost ratio of 15:1


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Benefits of road safety audit

Austroads, 1994 summarizes the benefits ofroad safety audit

The possibility of crashes on the road network canbe reduced

The severity of crashes can be reduces

Road safety is given greater prominence in themind of road designers and traffic engineers

The need for costly remedial work is reduced

The total cost of the project to the community isreduced

p_road safety audit chap 15

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