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A Framework for Risk Management in Railway Sector: Application to Road-Rail Level Crossings

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  • Ecole Mohammadia d'Ingénieurs, Mohammed V University in Rabat

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A major concern in rail industry worldwide is to ensure safety in railway operations in general and at road/rail level crossings in particular where the number of fatal accidents has been significantly increasing over the years. Accidents at level crossings are the result of complex interactions between factors arising from the design and operations of level crossings. An important first step towards eliminating the causes of these accidents is thru understanding and assessing the risks associated with a given level crossing and acting on them. This paper introduces a risk management framework that serves this purpose. The suggested framework involves several activities, including, hazard identification, risk analysis, evaluation, treatment and control. Having explained the suggested framework, this paper illustrates how it can be systematically applied to mitigate risk at a given Moroccan level crossing. The efficiency and success of the suggested risk management framework are pending its integration in a global rail safety management system also introduced in the paper.
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34 The Open Transportation Journal, 2011, 5, 34-44
1874-4478/11 2011 Bentham Open
Open Access
A Framework for Risk Management in Railway Sector: Application to
Road-Rail Level Crossings
Abdelaziz Berrado*,1, El-Miloudi El-Koursi2, Abdelghani Cherkaoui3 and Moha Khaddour4
1EMI, Université Mohammed V/UIR, Rabat, Morocco
2INRETS, Lille, France
3EMI, Université Mohammed V, Rabat, Morocco
4ONCF, Rabat, Morocco
Abstract: A major concern in rail industry worldwide is to ensure safety in railway operations in general and at road/rail
level crossings in particular where the number of fatal accidents has been significantly increasing over the years.
Accidents at level crossings are the result of complex interactions between factors arising from the design and operations
of level crossings. An important first step towards eliminating the causes of these accidents is thru understanding and
assessing the risks associated with a given level crossing and acting on them. This paper introduces a risk management
framework that serves this purpose. The suggested framework involves several activities, including, hazard identification,
risk analysis, evaluation, treatment and control. Having explained the suggested framework, this paper illustrates how it
can be systematically applied to mitigate risk at a given Moroccan level crossing. The efficiency and success of the
suggested risk management framework are pending its integration in a global rail safety management system also
introduced in the paper.
Keywords: Risk, risk management, safety management, railway sector, level crossings.
1. INTRODUCTION
Railways are regarded as an economic, efficient,
environmentally friendly and very safe mode of transport.
However, in the recent past, the European Community has
noted the loss of a substantial share of the railway market to
other modes of transport. The liberalized rail transport market
similar to those in the civil aviation and maritime sectors
requires some major changes in current practices, such as
introduction of more self-regulation for companies operating in
the rail sector, and increased openness and transparency in all
member state railways. A common safety policy is essential to
the future of the industry in Europe. Harmonization of the
regulatory framework is seen as a key part of creating this
commonality. In recent years, the European Commission has
begun to develop several railway initiatives, which are aimed at
encouraging open market policy and harmonizing the railways
in Europe to facilitate horizontal integration( i.e. interoperability
of the networks facilitating smooth movement of passenger and
freight trains), vertical separation( e.g. between management of
infrastructure and train operation and outsourcing of
maintenance and support functions) and a due and transparent
certification process to improve safety approval and equipment
acceptance. In addition to the major legislative changes that
have been undertaken across the European community in the
last few years, there are ongoing technological changes that are
occurring. Therefore there is the potential for instability and
confusion in the railway industry resulting in an overall
*Address correspondence to this author at the EMI, Université Mohammed
V, Rabat, Morocco; Tel: +212 661 267 599; Fax: +212 537 778 853;
E-mail: berrado@emi.ac.ma
increase in accident risk. These changes affect not only the
organizational and technical innovations developed with the
new systems, but also the new stakeholders and financial
arrangements derived from the major changes.
Railway safety is even more question able at road rail
level crossing (LC) where the number of fatal accidents has
been significant over the years. A major concern is to
understand and remove the risks in railway operations in
general and at LC in particular.
The subject of risk has increasingly become a point of
shared interest between many entities representing different
sectors. According to a definition of the United Nations, risk
“refers to the expected losses from a particular hazard to a
specified element at risk in a particular future time period.
Losses may be estimated in terms of human lives, or
infrastructure d amaged or in financial terms”. In this paper
we introduce a risk management framework that can be used
to build a generic risk model which will lead to increasing
the understanding of risk profiles at railways and will allow
for risk based decision making to take place via a structured
representation of the causes and consequences of potential
accidents arising from the operations of railways. We
illustrate how the suggested framework can be used for risk
assessment at road/rail level crossing. The suggested
framework could be easily adjusted to model risk in other
sectors as well. Furthermore, we explain how the suggested
risk management framework can be integrated into a global
safety management system in the railway sector.
The rest of this paper is organized in four sections. In the
following section, we introduce the suggested risk
management framework and explain its different
A Framework for Risk Management in Railway Sector The Open Transportation Journal, 2011, Volume 5 35
components. In section 3, we focus on the integration of the
suggested framework into the global safety management
system in the railway sector. A Moroccan level crossing is
then used in Section 4 to illustrate how the suggested risk
management framework is applied to tackle risk at LC. A
conclusion follows.
2. RISK AND THE RISK MANAGEMENT PROCESS
The subject of risk has increasingly become a point of
shared interest between many entities representing different
sectors. This gave rise to different but converging definitions
of risk [1-5]. Risk has been defined both qualitatively and
quantitatively. Modares [3] defines risk qualitatively as the
potential of loss or injury resulting from exposure to hazards.
A hazard being considered as source of danger that is not
associated to the likelihood with which that danger will
actually lead to negative consequences. Quantitative
definitions of risk associate hazards with their probability of
nuisance to the people and the environment. For instance in
[6], risk is defined to be a set of scenarios (Si), each of which
having a probability (or frequency Pi) and a consequence Ci.
This quantitative definition to risk aims to estimate the
degree or probability of loss related directly to the
occurrence of hazards or potential failures of a system.
An organization faces essentially three different types of
risk to its operations, namely internal risks, i.e. those
associated with activities and locations for which the
organization is solely responsible, external risks, i.e. those
originating from systems, people or organizations and
processes that are outside the organization’s control and
shared risks, i.e. risks associated with activities or locations
for which there are shared responsibilities rather than sole
ownership; to manage such risks the organizations have to
ensure that compatible approaches are used.
The need for practical assistance in applying risk
management in public and private sector organizations, has led
to the development of standards on risk management such as
The Risk Management Standard [7] and the Australian and New
Zealand standard on risk management [8].
The risk management process as set out in the standards
consists mainly of five sequential stages, as illustrated in Fig.
(1), beginning with the establishment of the context within
which risk has to be evaluated in order to set both the
objectives and scope of the system; this entails an exhaustive
and detailed description of the system that is at risk. Having
delimited the system, one should identify the potential
hazards or sources of risk; in this stage the list of initiating
events, Ei, or scenarios of events leading to the undesired
outcome is enumerated. Those events include essentially
internal and/or external failures of both the technology used
and the human force responsible for it. The next stage,
usually referred to as risk analysis is reserved for estimating
the likelihood, Pi, of the scenarios or events Ei, actually
occurring and each scenario’s consequen ce, Ci, is also
estimated. The results of the risk analysis stage are thereafter
used to compare and rank the various risk drivers and
compute the total expected risk value, R, defined as: R = Ri
where Ri = Pi Ci is the expected risk value associated with
event Ei,, the risk analysis is illustrated in Fig. (1). In the
evaluation stage minor risks may be screened out and more
attention will be routed towards risks with highest expected
risk value. Risk treatment is the final stage, where action
plans are determined in response to the identified risks and
mechanism to control those risks are put in place. It should
be noted that this risk management process may well require
regular monitoring and review especially when applied with
dynamic systems which may evolve over time. Successful
risk management requires that all parties who need to be
involved at any stage are given adequate opportunity to do so
and play an active role in the process and are kept informed
of any developments and actions resulting from the process.
2.1. Existing Hazard Identification Techniques
Hazard identification is often seen as the heart of risk
management. The successful accomplishment of this task is
critical since if one omits some potential hazards, it could
result in severe human loss and infrastructure damage and in
a misevaluation of risk. Many hazard identification
techniques [9] have been developed in various engineering
disciplines. The precursors of these methods were from the
Chemical, Aeronautical and Nuclear power industries. Some
methods are area specific such as Hazard Analysis and
Critical Control Point (HACCP) for the food industry and
others that can be applied to almost any system.
Fig. (1). Flow chart of a generic risk management process.
36 The Open Transportation Journal, 2011, Volume 5 Berrado et al.
Preliminary Hazard Analysis (PHA) is defined in [10] as
a semi-qu antitative analysis that is performed to identify all
potential hazards and accidental events that may lead to an
accident then rank them according to their severity and
thereafter identify required hazard controls and follow-up
actions. Several variants of PHA are used, and sometimes
under different names for instance Rapid Risk Ranking
(RRR) and hazard identification (HAZID). The Preliminary
Hazard Analysis (PHA) provides an initial overview of the
hazards present in the overall flow of the operations of any
system. It provides a hazard assessment that is broad, but
usually not detailed. The PHA will often serve as the total
hazard identification process when risk is low. In higher risk
operations, it serves to focus and prioritize follow-on hazard
analyses by displaying the full range of risk issues. PHA can
be applied to all subsystems, components and systems. Most
of the time, it is performed first, prior to or as an initial step
of design, operation, maintenance, and refurbishment. PHA
is carried out in four main step beginning with PHA
prerequisites where the PHA team is established, the system
to be analyzed, its components, boundaries and interactions
are defined and described as well as the actors or materials
that appear to be the most exposed to risk. Next, all hazards
and possible accidental events must be identified. In the third
step of PHA, the consequence or severity of the hazards in
terms of infrastructure damage, human injury or loss is
evaluated and frequency of those identified hazards is also
estimated. Severity and frequency classification may be used
instead when historical risk data is not available to make
accurate estimations. Finally, the different hazards are
ranked in categories based on their severities and
frequencies; this may be done through the application of the
ALARP principle [1] explained in Section 3.3. Hazard
categorization helps identify which measures and follow up
actions should be carried out to remove hazards associated
with high risk.
Failure modes, effects, and criticality analysis (FMECA)
is a methodology to identify and analyze all potential failure
modes of the various parts of a system, the effects these
failures may have on the system and how to avoid the
failures, and/or mitigate the effects of the failures on the
system [10]. FMEA (Failure modes and effects analysis) is a
predecessor to FMECA. The C in FMECA indicates that the
criticality (or severity) of the various failure effects are
considered and ranked. Today, FMEA is often used as a
synonym for FMECA. Although FMECA was one of the
first systematic techniques for failure analysis, it is not able
to identity complex failure modes involving multiple failures
within a subsystem. In other words, it has difficulty
identifying hazards that are due to complex interactions of
failures. Furthermore it has a limited examination of human
error and external influences. FMECA remains the most
widely used reliability an alysis technique in the initial stages
of product/system development, it is usually performed
during the conceptual and initial design phases of the system
in order to assure that all potential failure modes have been
considered and the proper provisions have been made to
eliminate these failures.
A Hazard and Operability (HAZOP) study [11] is a
structured and systematic examination of a planned or
existing process or operation in order to identify and
evaluate problems that may represent risks to personnel or
equipment, or that may prevent efficient operations. The
HAZOP technique was initially developed to analyze
chemical process systems, but has later been extended to
other types of systems and also to complex operations and to
software systems. HAZOP is a qualitative technique which
uses special adjectives (such as "more,""less," "no," etc.:
being a unique feature) combined with process conditions
(such as speed, flow, pressure, etc.) to systematically
evaluate deviations from normal conditions. HAZOP also
ranks risk based on severity and likelihood and is best suited
for the identification of safety hazards and operability
problems of continuous process systems, especially fluid and
thermal systems and also to review procedures and
sequential operations. A major limitation of HAZOP and of
the techniques that we introduced thus far is that they focu s
on one-event causes of deviations.
Multiple-phase failures or hazards due to complex
interactions of simple events have to be identified based on
the hazards previously identified. Several tools are available
for this purpose, including Fault and Event Tree Analysis,
Bayesian Belief Networks, Cause-Effect Diagrams and
Reliability Block Diagrams.
A Bayesian Network is a directed acyclic graphical
representation of the joint probability distribution for a set of
discrete variables. To each variable A is attached the
conditional probability of A given the parents of A. The
graphical representation makes Bayesian networks a flexible
tool for constructing models of causal impact between
events, in particular when the causal impact has a random
nature. Bayesian Networks can be used to model hazards that
are the result of complex interactions of simple event.
Cause & Effect analysis (or Fishbone Analysis) provides
a structured way to think through all possible causes of a
problem, this tool consists of constructing fishbone
diagrams, introduced by Kaoru Ishikawa [12] and has been
successfully used to track and mitigate several quality
problems.
A Reliability Block Diagram [13] is a method of
modeling how the components (represented by "blocks") are
arranged and related reliability-wise in a larger system and
how they combine to cause system failure. Reliability block
diagrams may be analyzed to determine the critical
components from a reliability viewpoint and can be used to
identify multiphase h azards.
Event Tree Analysis (ETA) [1] and Fault Tree Analysis
(FTA) [14] are hazard identification methods which are able
to implement mu ltiple-phase failures, i.e. deal with complex
interactions. According to [1], those two methodologies give
rise to a pictorial representation of a Statement in Boolean
logic. ETA uses “forward logic”, beginning by an abnormal
(initiating) incident or event and propagate it through the
system under study by considering all possible ways in
which it can affect the behavior of the (sub) system. It takes
into account whether installed safety barriers are functioning
or not, and addition al events and factors. After identifying all
potential accidental events using a PHA, a HAZOP, or some
other technique, ETA helps identify all potential accident
scenarios and sequences in a complex system. ETA
generates qualitative descriptions of potential problems as
combinations of events producing various types of problems
A Framework for Risk Management in Railway Sector The Open Transportation Journal, 2011, Volume 5 37
(range of outcomes) from initiating events. It also produces
quantitative estimates of event frequencies or likelihoods and
relative importance of various failure sequences and
contributing events. This enables giving recommendations
for reducing risks and evaluating their effectiveness. ETA is
however limited to one initiating event and can easily
overlook subtle system dependencies.
On the other hand, FTA uses backward logic, starting
from a top event (a potential accident of interest) to seek all
the ways it can happen. The analysis proceeds by
determining how the top event can be caused by individual
or combined lower level failures or events. The causes of the
top event are connected through logic gates. Fault trees
generate qualitative descriptions of potential problems and
combinations of events causing specific problems of interest
and also quantitative estimates of failure frequencies and
likelihoods, and relative importance of various failure
sequences and contributing events. FTA is the most
commonly used technique for causal analysis in risk and
reliability studies, it has, however, a narrow focus since fault
trees zoom on one specific accident; furthermore significant
expertise is required for quantification of frequencies.
2.2. Risk Analysis
Risk Analysis consists of the estimation of the frequency
of the accidental events and their respective consequences.
The frequency of the accidental events may be estimated
based on historical data of previous incidents, fault tree
analysis or expert judgment.
The consequence analysis identifies both immediate
consequences and those that are not apparent until sometime
after the accidental event. All potential event chains
following an accidental event must be identified and
described. Consequence analysis may be conducted using
event tree analysis, simulations or can be derived from
historical data. Cause-consequence analysis [15] is another
technique for consequence analysis which explores system
responses to an initiating "challenge" and enables assessment
of the probabilities of unfavorable outcomes at each of a
number of mutually exclusive loss levels. This technique
provides data similar to that available with an event tree;
however, it offers two advantages over the event tree; time
sequencing of events is better portrayed, and discrete, staged
levels of outcome are an alyzed.
It is important to include all consequence categories,
these include for the case of level crossing, rail company
personnel, passengers, the environment (road side of LC),
the economic impact, operational consequences and rail
company reputation. Losses may be estimated in terms of
human lives, or infrastructure damaged or in financial terms”
[16-18]. Loss of Livelihood should also be included when
estimating losses, livelihood being defined as “the command
as individual, family or other group has over an income
and/or bundle of resources that can be used or exchanged to
satisfy its needs” [19].
In the absence of data, one can adopt an ordinal scale for
hazard frequency classification and consequence or severity
classification. Tables 1 and 2 give possible classifications for
hazard frequency and consequence.
2.3. Risk Evaluation
If all the consequences and frequencies of hazards have
been identified then quantitative definition of risk can be
used to estimate risk:
R=Ri where Ri =Pi.Ci (1)
Table 1. Hazard Frequency Classification
Score Frequency Class
1 Very unlikely
2 Remote
3 Occasional
4 Probable
5 Frequent
Table 2. Consequence/Severity Classification
Score Severity Class
1 Minor
2 Major
3 Critical
4 Catastrophic
In the risk evaluation step, the existing risks are classified
and decisions are made regarding the tolerability of the
existing risk. Risk toler ability is generally a complicated and
multifaceted issue which raises philosophical questions from
several angles. Epistemologically one is led to ask: How can
we know exactly what a risk is? (Objective vs Subjective
assessment). Ethical and political questions include, for
instance, the following: Who should assess the acceptability
of a risk? Stakeholders vs Mathematicians? Another question
is about distribution of risks in society whether the
distribution is fair? Several principles can be used to
determine the acceptable risk:
The precautionary principle [20] is a moral and political
principle which states that if an action or policy might cause
severe or irreversible harm to the public, in the absence of a
scientific consensus that harm would not ensue, the burden
of proof falls on those who would advocate taking the action.
GAME or GAMAB meaning “globally at least
equivalent” [21], can be applied when looking at either
individual or collective risk. This criterion is based on the
requirement that the total risk inherent in any new system
must not exceed the total risk inherent in comp arable
existing systems. It is assumed that the risk level of existing
systems can be assessed (e.g., using existing statistics). The
respective risk levels of an existing system and a new system
can only be compared if both systems have comparable
performance characteristics and operating conditions.
MEM (minimum endogenous mortality) [21] requires
that the total risk from all technical systems affecting an
individual must not exceed minimum human mortality (2E-4
deaths per person per year).
38 The Open Transportation Journal, 2011, Volume 5 Berrado et al.
ALARP principle [21] ensures that the risks of any
system with serious consequences in terms of human loss
and injuries, is kep t to a level which is As Low As is
Reasonably Practicable. ALARP defines three risk levels:
Intolerable Risk, which cannot be justified or
accepted, except in extraordinary circumstances
Tolerable Risk, which can be accepted only if risk
reduction is impractical or if the cost or risk reduction
greatly exceeds the benefit gained
Negligible Risk, which is broadly acceptable and does
not require risk mitigating measures
If risk is determined to be at the intolerable level,
measures must be taken to reduce it immediately to a
tolerable level. If risk is found to be at tolerable level, risk
mitigating measures should still be applied, provided that a
cost benefit analysis is in favor of it. Table 3 illustrates a risk
classification matrix based on ALARP principle.
2.4. Risk Treatment and Control
Risk treatment is the process of selecting and
implementing measures to reduce see remove the risks.
Having identified all sources of risks, one will need to
prioritize risk treatment actions and target high risk before
low risk while maximizing the benefit of the organization.
Two major classes of methods are considered while
prioritizing risk treatment actions including Economic
Evaluation and Social Evaluation. Social Evaluation is usually
used as a prerequisite to the Economic evaluation in decision
making as there are a number of factors that cannot be assessed
economically. The Econo mic Evaluation estimates the expected
benefits and anticipated costs of control associated with varying
degrees of reduction in risk, using monetary criteria which are
amenable to quantitative economic analysis. Several types of
analysis techniques can be used for economic evaluation of risk
treatment alternatives at level crossings including, cost benefit
analysis, cost effectiveness analysis and risk benefit analysis
[22].
Cost-Benefit Analysis (CBA), also termed benefit-cost
analysis or risk-cost-benefit analysis, is a technique that
compares for various risk reduction scenarios, the estimated
costs of controls put in place against the benefits of the
reduced likelihood of accident at LC. This technique
calculates the monetized benefit-cost ratio which indicates,
when found greater than one (less than one), that projects
benefits will likely outweigh the cost of the controls (costs
outweigh the benefits). Non-economic considerations should
help decide when a risk removal strategy with a benefit-cost
ratio inferior to 1 should still be retained. A major difficulty
in CBA is that the Costs, Disbenefits and Benefits should be
translated into their equivalent monetary value before the
benefit cost ratios can be estimated out. It is, however, very
difficult to estimate and reach agreement on the economic
impacts of benefits and disbenefits for projects intending to
put in place controls for risk reduction at LC. Furthermore, a
viewpoint must be established (usually after a strong debate
in the political arena between different groups) before the
economic evaluation. The viewpoint finally adopted will
determine the estimates of costs, Benefits and Disbenefits. It
should be noted that quantification of the benefits of risk
reduction alternatives in monetary terms is an important part
of CBA. Various techniques for making quantitative
estimates can be used including revealed preferences and
stated preferences methods [22]. Revealed preference
methods allow an analyst to infer values from actions, for
example one revealed preference method involves measuring
prices in benefits in two risk reduction alternatives that are
distinguished only by an externality; for example building or
not building a bridge to replace a given LC, building a bridge
may have an incidence on the economic value of real estate
around the LC, this increase or decrease will reflect the
monetary benefits or disbenefits of building the bridge to
replace the LC. On the other hand, the stated or expressed
preference methods consist of using psychometric surveys
for asking people about their preferences. They are used
especially where no market value actu ally exists. For
example, surveys may be used to ask people of what they are
willing to pay to save a human life. This monetary amount
can be used to represent what people are willing to pay to
increase safety at a LC.
The Cost-Effectiveness Analysis (CEA) technique
compares the projected costs for a range of proposed risk
control alternatives, all intended to meet th e same objective.
Although straightforward, this method does not take into
account of social and political factors unless they can be
somehow converted in monetary value. CEA differs from
CBA in that benefits are expressed in physical units (e.g. in
LC context, number of life to be saved) rather than in money
units. Costs, as in CBA, are expressed in monetary terms.
CEA is useful in areas such as health, accident safety and
education where it is often easier to quantify benefits in
physical terms than to value them in dollars. CEA is useful
most often when the benefits of a risk reduction scenario are
difficult to quantify in monetary terms but the government
wishes to know which option will achieve social benefits or
government objectives most cost effectively. One limitation
Table 3. Hazard Categorization Based on ALARP Principle
Frequency /Conse quence 1
Very Unlikely
2
Remote
3
Occasional
4
Probable
5
Frequent
Catastrophic
Critical
Major
Minor
Negligible Risk
Tolerable Risk
Intolerable Risk
A Framework for Risk Management in Railway Sector The Open Transportation Journal, 2011, Volume 5 39
of CEA is that it applies only to situations where all of
proposed risk control alternatives are intended to meet the
same physical objective.
A Risk benefit Analysis calculates the benefits of the
proposed risk control alternatives as a reduction in estimated
risk and is not converted to a monetary unit. Risk benefit
analysis attempts to define the relation between a given
amount of risk reduction (e.g. reduction of frequency of
accidents at a LC) and the cost of control measures necessary
to achieve it. Risk benefit analysis is frequently the most
credible risk management technique when attempting to
control high risk situations (e.g. risk of contamination due to
transportation of high-risk contaminants). It is wider in scope
than the cost effectiveness analysis. A notable advantage of
risk benefit analysis is that it does not require the conversion
of the benefit into monetary measures. It requires, however,
a prior determination of what an acceptable level of risk is.
A major component of risk treatment is risk control
which consists of putting in place control mechanisms to
make sure that risk is permanently removed/decreased.
2.5. Monitoring and Reviewing the Risk Management
Process
Monitoring and review of the risk management process is a
mean to make sure that the actions taken effective and that the
procedures adopted and information gathered throughout the
process were appropriate. It should be noted that systems are
evolving which means that they may get exposed to new risks
as they evolve over time, reviewing and monitoring enable
keeping track of the changes that systems may undergo.
3. GLOBAL SAFETY MANAGEMENT SYSTEM IN
THE RAILWAY SECTOR
3.1. Definition of a Safety Management System
Safety management is an important issue in all safety
critical sectors including railway industry and regarded as an
important means for improving safety culture.
A safety management system (SMS) [23] is an
organization’s formal arrangement, through the provision of
policies, resources and processes, to ensure the safety of its
work activity. An effective SMS helps the organization to
identify and manage risks effectively. It allows an organization
to demonstrate its capability in ach ieving its safety ob jectives
and in meeting regulatory requ irements. A crucial aspect of
safety management activity will be the management of
interfaces. The number of interfaces has increased significantly
due to the liberalized rail transport and new organizational
structure worldwide and in Europe in particular.
3.2. Safety Management System and Lifecycle Stages of
the Railway Transport System
The main lifecycle stages of a Railway Transport System
have been discussed in European norms [21] and other
similar documents, a schematic view of this is presented in
Fig. (2).
Mainly, the SMS framework focuses on generic
management issues. Its actual effectiveness very much
depends on how this framework is applied to the specific
business processes related to the systems, subsystems and
equipment the duty holder controls. There should be specific
elements of any developed SMS that deal with aspects of
each of the following stages of the Railway Transport
System lifecycle:
Pre-operation: Safety approval, system handover and
acceptance are therefore crucial interfaces between
the developer and the duty-holder that need to be
managed effectively to ensure safety. The duty-
holders need to assure themselves that the system
development has been undertaken in a manner that is
consistent with the risk tolerability criteria set for this
overall Railway Transport System SMS framework.
This assurance will be supported by evidence of
application of a robust development process such as
that described in safety CENELEC standards or
equivalent [21, 24]. This approach implies that the
developer should be aware of the risk tolerability
criteria. The duty-holder must also assure itself that
the overall system, within which any procured
element is to be used, remains safe. Each duty holder
should have in place necessary arrangements for
accepting new components. This should ensure that
only ‘operationally ready’ equipments, subsystems or
systems are accepted for operational usage. The
acceptance criteria used for such purposes should
comply with EU and national requirement, and their
integration and commissioning procedures with the
Railway Transportation System should be identified.
Operation: The duty holder should have the necessary
arrangements for identifying the operating
requirements of the equipment, subsystems and
systems it controls. They should include requirements
and constraints for their normal and degraded modes
of operation. Generally, regulations, rulebooks and
work procedures provide detailed instructions for
performing critical operations. The duty holder
organization should specify how these rulebooks are
to be developed, how the rules will be formulated,
written and approved; how the use of rules will be
monitored and, where appropriate, how the rules will
be enforced or modified and maintained to improve
their performances.
Maintenance: A duty holder should have adequate
arrangements for implementing planned and
preventative maintenance (including, where
appropriate, maintenance based on monitoring of
equipment condition) of its equipment, subsystems
and systems. All such items should be identified,
prioritized in terms of frequency and standard of
maintenance and adequate resources identified to
meet the maintenance schedules. The procedures for
removing items from the operation and for preparing
them for maintenance should be identified. Similarly,
procedures for commissioning and accepting repaired
items for operational use should be identified.
Renewal: A duty-holder should have necessary
arrangements for identifying and planning renewal
work which it has to undertake for regulatory or
business reasons. For example, for maintaining
performance level a duty holder may need to carry
out like for like replacement for time-expired assets,
or introduce new technology to improve performance.
40 The Open Transportation Journal, 2011, Volume 5 Berrado et al.
There should be procedures for monitoring critical
items and preparing plans for their timely
replacement.
A key source of risk is at the transition between lifecycle
phases, e.g. the resumption of operations after a period of
maintenance. Lifecycle transition should be explicitly
addressed in risk assessment activity. It is assumed that all
the concerned work places, e.g. operational area,
maintenance depot and project site should be subjected to
required Health and Safety at Work regulations.
3.3. Integrating the Suggested Risk Management Frame-
work into Railway Safety Management System
Table 4 shows the proposed eleven elements of the SMS
that are divided into two parts: Planning and risk control
system and learning system. This organization of SMS
structure should be refined at Stakeholders level and should
consider the operation, maintenance and renewal phases of the
life cycle [21] of the railway system and lifecycle transition
should be explicitly considered in risk assessment activity. The
risk management framework for railway sector which we
suggested in Section 2 can be integrated in element (5) of a
SMS.
4. RISK ASSESSMENT FOR LEVEL CROSSINGS:
APPLICATION TO A MOROCCAN LEVEL CROSSING
4.1. Description of the System Under Study
A level crossing (LC) is an intersection between the road
and the railway that allows vehicles of any type to pass through
it. The “danger zone” is the area of the intersection in which a
collision between the incoming train and LC road users
(vehicles and pedestrians crossing the LC) can take place. LCs
differ in the protection they offer users, their degree of usage,
and in the speed and frequency of the trains that pass over them.
LCs are categorized into active crossings where the road user is
given a warning of incoming train or passive crossings where no
warning is provided, the responsibility being on the road users
to determine whether it is safe to cross the LC. Moreover, active
LCs can be split into two major subcategories i.e. manual and
automatic LCs. In Morocco, the only type of active LC used is
the manu ally controlled full-barriers (MCB) which will serve as
the basis of our risk assessment study. The Moroccan LC
studied is composed of two rail tracks, and is crossed by a two-
way road. The LC is operated by a LC keeper who is
responsible for lifting and lowering the mechanical full-barriers
and also for alerting the different LC actors of the presence of
danger at the LC.
Technical Characteristics of the Moroccan Level Crossings
The Moroccan national railway organization, ONCF,
classifies its LCs according to two criteria, namely LC moments
and their location. The LC moment corresponds to the number
of trains and vehicles (cars and motorcycles) that pass through
the LC in a 24 hours period:
LC moment = [Number of trains / 24h] (2)
* [Number of Vehicles / 24h]
The second criterion, which is related to the location of the
LC, corresponds to the visibility of the incoming train by the
vehicles drivers. In fact, ONCF defines a sufficient visibility
when a person being at 5 meters from the nearest rail track and
whose eye is at one meter from the ground sees the complete
locomotive (railway engine used to tow railway cars), moving at
the maximum authorized speed, for a period of 20 seconds.
The ONCF classifies LC with a moment in the interval
[2000, 5000] and insufficient visibility as first category. These
first category level crossings are manually controlled barriers
LC and are the subject of our study.
Railwa y Signaling
The railway signals include:
A metallic announcing panel made out of light-
sensitive tapes representing a barrier with the LC
number at the top of it. This panel is placed before
Fig. (2). Appropriate SMS guidance for each lifecycle phase.
A Framework for Risk Management in Railway Sector The Open Transportation Journal, 2011, Volume 5 41
and after the LC at a distance of 700 m when the
authorized train speed does not exceed 120 km/h and
at 800 m when this speed is greater than 120 km/h.
An « S » panel placed at 300 m before and after the
LC to remind the train driver that he should whistle to
alert both the LC keeper and the vehicles passing
through the LC of its incoming.
White-painted pylons located at least at 500 m before
and after the LC
Road Signaling
There exist two types of road signals, advanced signals
and position signals:
The Advanced Signal is a triangular panel A9 placed
at 150 m from the LC which informs the road users
that they are approaching a MCB LC and that they
should decelerate and be cautious at the LC.
Position Signals are barriers with tapes of 1 meter
length each painted in red and white.
Incoming Train Detection System-Electro-Mechanical
Detection
ONCF is using Electro-Mechanical oriented pedal in all
Train Detection System (TDS) at manned LC. This
automated TDS is composed of pedals placed at the middle
of each rail track of the railway 3000 m from the LC. The
TDS is directly connected via electrical wires to the LC’s
control board and when activated the TDS will trigger both
the audible and visual signals at the LC, indicating the
direction of the incoming train. These devices are installed in
a box located at proximity from the LC Keeper’s shelter and
the barriers so that the LC keeper can hear and see it
perfectly. When the train passes on the rail track, it activates
mechanically the pedals, then the road signal changes from
green to red. The incoming train’s audible announcement can
only be turned off if both the LC keeper deactivates the
system by pushing on a button on his control board and the
pedal is no longer active, train passed the location of the
pedals.
Entities Involved in the Moroccan Manually Controlled
Full Barriers Crossings
Several entities may impact the normal operations of the
MCB crossings, including the condition of the railway, the
condition of the road crossing the railway, the condition of
level crossing mechanisms, the train detection system, the
transmission/communication system, the road signaling, the
railway signaling and the level crossing human actors which
include the train driver, the level crossing keeper, the road
user and the control center operator.
Modeling Operational Interactions at the LC Through
Functional Diagrams
Many of the existing hazards at LC may be due to
operational failures which can be identified by building
functional diagrams representing the LC from different
perspective and then identifying operational conditions
which may lead to accidents. These functional diagrams give
a visual representation of the sequence of events and
interactions between the different entities involved in the LC
operations and enable a detailed functional understanding of
the system. For this purpose we built functional diagrams,
for the LC under study, from the perspectives of the different
actors in the LC including the LC keeper, the road user, the
train driver and control center operator.
4.2. Hazard Identification at MCB Moroccan LC
In order to identify the complete set of hazards
surrounding the MCB LC under study, we considered the
different entities involved in the LC and the interactions
between them described by functional diagrams. We also
reviewed the operational specifications and considered all
the environment factors around the LC. We considered the
human and LC interface. We identified several hazards that
can be classified into one of five categories, namely hazards
related to the environmen t of the LC which affect visibility
of LC users, hazards related to technical problems, hazards
due to non compliance with standards, hazards due to the
human factors, and the fifth category includes all the other
hazards. Several sub-categories constitute each hazard
Table 4. Structure of Safety Management System
Planning and Risk Control System Learning System
(1) Nature and Scope of Duty Holder’s Business (10) Incident and Accident Reporting and Learning
(2) Safety Policy
(3)Organisational structure and Responsibilities (11) Monitoring, Auditing, Corrective Measures and Annual
Reports
(4) Competence, Training and Fitness
(5) Risk Management
(6) Safety Assurance
(7)Emergency Management
(8) Safety Communication and Information
(9) Management of Rules and Standards, including Compliance
42 The Open Transportation Journal, 2011, Volume 5 Berrado et al.
category. After several brainstorming sessions, we identified
63 potential hazards along the five hazard categories. We
present in Table 5 a sample of the identified hazards.
The pie-chart in Fig. (3) illustrates the distribution of the
hazards identified by category. According to this chart, the
hazard categories, “Human Factors” and “Technical
Problems”, with respectively 37% and 29% of the overall
system hazards identified, are the two major hazards that can
lead to an accident at the MCB LC. Therefore, a detailed
analysis of both categories was needed to understand and
identify which actors (people or sub-system parts) are
responsible for the majority of them and to state if some
actions can be undertaken by the appropriate authorities to
reduce their impact, as a future step.
4.3. Risk Analysis, Evaluation and Treatment at the
MCB Moro ccan LC
Since we did not have historical data for risk analysis, we
used the frequency and consequence classification described
in Tables 1 and 2 to rank each of the 63 identified hazards
and then categorized them based on ALARP principle as
explained in Table 3. This revealed that 18% of the hazards
are considered to have negligible risk, 35% have tolerable
risk and they include mainly technical problems related to
the train and the TDS. The remaining 47% hazards were
associated with the intolerable risk category, and most of
them were associated with the human factor and technical
problems. The next logical step is to take actions to remove
hazards with potential intolerable risk. These actions should
target human factors and technical problems.
5. CONCLUSION
In this paper, a framework for risk management at
railways has been introduced and integrated into global
safety management system of railways. Furthermore we
illustrate how it was applied to a manually controlled full
barrier road rail level crossing in Morocco. We suggested
different aspects that should be considered during the system
definition phase where we suggested using functional
diagrams for modeling operations at LC from the perspective
of LC actors. It is a critical part for risk management and
Table 5. A sample of the Ha zards Identified for the MCB Under Study
Hazards
Improperly closed gates when the train passes through the LC
Road vehicles coming over the LC where barriers on the other side have been closed
Drivers disregarding signals
Low level of public discipline
Technical Malfunction of a vehicle that makes it stop in the middle of the railway track while a train is coming towards the LC
Poor road surface state causing the crossing of vehicles difficult
Non-Compliance of road standards by the road authorities
Non-Compliance of railway standards by the railway authorities
Poor Maintenance of LC
Barriers take too much time to close and some vehicles cross the LC while the train is near by
Restricted Visibility of the Road signals by the drivers (due to the presence of physical obstructions)
Restricted Visibility of the railway signals by the train driver (due to the presence of physical obstructions)
Restricted Visibility of the Incoming Train (large turn angle or angle of the road)
Elevation of the road crossing the track that makes the car stall
Absence of Road Warnings and Signals
Motorcycles’ Drivers ignore signals and pass under the closed LC barriers
Light Signal is not working and do not alert both the LC keeper and its users
Non luminescent barriers (of use at night)
Train brakes do not work
Non-activation of the detection system & Train Alarm does not work
Car Drivers try to cross while the train approaches and the barriers are being lowered
Traffic jam at the level of the LC while a train is coming towards the LC
Signal Transmission between the activating arm of the TDS and the LC Control Board fails due to poor maintenance
Non-activation of the audible and light signals by the Train Detection System
Inaudible Alarm of the train that is meant to alert the LC keeper of its incoming
A Framework for Risk Management in Railway Sector The Open Transportation Journal, 2011, Volume 5 43
specifically for hazard identification where we provided
different techniques that can be used; our experience shows
that involvement of all stakeholders is a prerequisite to the
success to this phase. Initiating events can be unveiled
through brainstorming sessions and FTA can model complex
interactions of events that have the potential to lead to
accidents. Risk analysis can then be carried out provided that
historical LC accident and incident data is available to
estimate frequencies and consequences; ETA is the ideal tool
for estimating consequences of hazards due to multiple
causes. The existing risks are then classified and decisions
are made regarding their tolerab ility, the ALA RP principle
can serve this purpose. A cost benefit analysis then helps
prioritize risk treatment actions that should target intolerable
risks. Control mechanisms should be also put in place to
assess, monitor and review the risk control actions put in
place. Finally, we emphasize on the importance of having a
database of historical accidents and incidents at LC for the
success and efficiency for the suggested framework.
ACKNOWLEDGEMENTS
This work is conducted within SELCAT project funded
by European commission and we would like to thank all
project partners.
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Hazards Results by Cause Categories
Visib ility
9%
Techn ical Problems
29%
No n-Co mplian ce with
Standards
15%
Human Factors
37%
Other
10%
Fig. (3). Hazards Identification Results classified by cause categories.
44 The Open Transportation Journal, 2011, Volume 5 Berrado et al.
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Received: May 25, 2010 Revised: August 23, 2010 Accepted: September 29, 2010
© Berrado et al.; Licensee Bentham Open.
This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/
3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
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