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Salmon,P. M., Lenne, M. G., Read, G. J. M., Mulvihill, C. M., Cornelissen, M., Walker, G. H., Young, K. L., Stevens, N. & N. A. Stanton (2016) More than meets the eye: using cognitive work analysis to identify design requirements for safer rail level crossing systems. Applied Ergonomics, 53, 312-322

More than meets the eye: using cognitive work analysis to identify design requirements for safer rail level crossing systems

Paul M. Salmon1, Michael G. Lenné2, Gemma J. M. Read2, Christine M. Mulvihill2, Miranda Cornelissen3, Guy H. Walker4 , Neville A. Stanton5 , Kristie L. Young2, & Nicholas Stevens1

1University of the Sunshine Coast Accident Research (USCAR), Faculty of Arts and Business, University of the Sunshine Coast, Maroochydore, QLD 4558, Australia

2Human Factors Group, Monash University Accident Research Centre,Building 70, Clayton Campus, Monash University, Victoria 3800, Australia

3Aviation, Griffith University, Nathan Campus, Brisbane, QLD4School of the Built Environment, Heriot-Watt University, Edinburgh, EH14 4AS, UK

5Transportation Research Group, University of Southampton, Highfield, Southampton, SO51 7JH, UK.

Abstract

Worldwide, the problem of collisions between people and trains at rail level crossings

remains resistant to current countermeasures. It has been suggested that this may be, in

part, due to a lack of systems thinking during design, crash analysis, and countermeasure

development. This paper presents a systems analysis of current rail level crossing systems in

Australia that was undertaken specifically to identify design requirements to improve safety

in rail level crossing environments. Cognitive work analysis was used to analyse current rail

level crossing systems based on data derived from a range of activities, including on-road

studies, cognitive task analysis interviews, a survey study, documentation review, and

subject matter expert workshops. Overall the analysis identified a range of instances where

modification or redesign in line with systems thinking could potentially improve behaviour

and safety. A notable finding is that there are various issues outside of the physical rail level

crossing infrastructure itself that may require modification. The implications for future rail

level crossing design activities are discussed.

Keywords: Rail level crossings, cognitive work analysis, systems analysis, road safety, rail safety


Introduction

Worldwide, the problem of collisions between people and trains at rail level crossings

remains resistant to current countermeasures. There are many articles available which

present the figures around unacceptable crash and fatality rates in different jurisdictions

(e.g. Evans, 2011; Hao and Daniel, 2014). In Australia, for example, between 2000 and 2009

almost 700 collisions between road vehicles and trains at rail level crossings led to close to

100 fatalities (Independent Transport Safety Regulator, 2011). Despite safety initiatives, in

2011 there were 49 collisions between trains and road vehicles at rail level crossing in

Australia, leading to 33 fatalities (ATSB, 2012). Moreover, the problem is not only limited to

collisions between trains and vehicles; data shows, for example, that there were 92

collisions between trains and pedestrians at RLXs between 2002 and 2012 (Australian

Transport Safety Bureau, 2012). The issue represents a ‘systems’ problem in that all users of

rail level crossings have some risk of being involved in a collision.

The continued incidence of trauma at rail level crossings is unacceptable, and provides clear

evidence that the current approach to rail level crossing safety is failing. In recent times

researchers have suggested that this may be due to the fact that there is a general lack of

understanding of behaviour at rail level crossings (Edquist et al, 2009) and also because a

systems thinking approach has not been adopted when attempting to improve rail level

crossing designs (e.g. Read et al, 2013; Salmon et al, 2013; Wilson and Norris, 2005). In the

case of the latter, it is argued that a focus on components in isolation (such as road users, or

warnings) has led to incremental design changes that can have only marginal effects. This


‘fix the broken component’ mentality has previously received criticism and is generally

accepted to be a limited approach to safety management (Dekker, 2011). It is also

acknowledged to be inappropriate within complex sociotechnical systems such as road and

rail (Salmon and Lenné, 2015); however, despite repeated calls, a systems thinking approach

to rail level crossing safety is yet to materialise (Read et al, 2013).

Developing appropriate system reforms for rail level crossings requires first that an in-depth

understanding of the rail level crossing ‘system’ be developed. Although this is seemingly an

obvious requirement, such an understanding does not currently exist (Read et al, 2013). This

article is a direct response to this knowledge gap and provides the first step in implementing

a systems thinking approach to rail level crossing safety by presenting a systems analysis of

rail level crossing systems in Victoria, Australia. Specifically, the outputs of a four phase

Cognitive Work Analysis (CWA; Vicente, 1999) of rail level crossings are presented along

with their key findings. The aim is to communicate and synthesise the findings from each

analysis phase and to generate a series of design requirements for safer rail level crossing

systems. A secondary aim is the further showcase the utility of CWA as an appropriate

systems analysis framework for transportation safety applications.

Cognitive Work Analysis

CWA (Vicente, 1999) is a systems analysis and design framework that has previously been

used both to analyse complex sociotechnical systems and to inform system design or

redesign activities (e.g. Cornelissen, Salmon, Stanton and McClure, 2015; Jenkins, Stanton,


Salmon and Walker, 2011; Rechard, Bignon, Berruet, and Morineau, 2015; Stanton and

Bessell, 2014; McIlroy and Stanton, 2011). An important feature of the framework is that

the analysis methods employed focus on identifying the constraints imposed on behaviour

within the system. As a result the design recommendations generated often centre on

making constraints more explicit to users, removing constraints on behaviour or better

exploiting existing constraints to support behaviour.

The framework itself comprises five separate analysis phases. In the present study four of

these phases were used. A brief description of each of the phases employed is given below

along with a table showing example rail level crossing outputs related to each phase (see

Table 1). For a full description of the framework the reader is referred to Vicente (1999) or

Jenkins et al (2008).

Table 1. CWA phases, outputs, and rail level crossing examplesCWA Phase Outputs Rail level crossing exampleWork Domain Analysis

Abstraction hierarchy model of the system including functional purpose, values and priority measures, generalised functions, and physical objects and their affordances

WDA model showing functional purposes of rail level crossing systems (e.g. provide access over rail line), values and priority measures (e.g. minimise collisions), functions (e.g. alert road user to presence of train), and physical objects (e.g. flashing lights) and their affordances (e.g. provide warning of train).

Control Task Analysis

Decision ladders showing decision making process for different key decisions along with short cuts made by experts

Contextual activity template showing the functions that occur across different situations

Decision ladder showing information, goals, and options related to the ‘stop or go’ decision at rail level crossings

Contextual activity template showing which functions occur in different rail level crossing situations (e.g. road user at crossing, train at crossing) and also which functions could occur through redesign efforts

Strategies Analysis

Strategies Analysis Diagram depicting the different strategies that can be used to

Strategies analysis diagram showing all of the different ways in which a different


undertake control tasks users (e.g. drivers, pedestrians, cyclists) can come to a stop or go decision at the rail level crossing

Social Organisation and Co-operation Analysis

WDA, decision ladders, and contextual activity templates shaded to show allocation of functions across different actors (human and non-human)

WDA showing which different actors currently perform the different functions required (e.g. which human and non-human actors perform the function ‘alert road user to presence of train’).

Work Domain Analysis

The first CWA phase, Work Domain Analysis (WDA), is used to provide an event and actor

independent description of the system under analysis: in this case rail level crossing

‘systems’. The aim of the WDA phase is to describe the purposes of the system and the

constraints imposed on the actions of any actor performing activities within that system

(Vicente, 1999). This is achieved by describing the system under analysis at the following

five conceptual levels using the abstraction hierarchy method:

1. Functional purpose – The overall purposes of the system and the external

constraints imposed on its operation;

2. Values and priority measures – The criteria that organizations use for measuring

progress towards the functional purposes;

3. Generalized functions – The general functions of the system that are necessary for

achieving the functional purposes;

4. Physical functions – The functional capabilities and limitations of the physical objects

within the system that enable the generalized functions; and

5. Physical objects – The physical objects within the system that are used to undertake


the generalized functions.

The output is a detailed description of the system under analysis in terms of the constraints

influencing behavior and the physical objects (and their affordances) and functions that

enable the system to achieve its functional purpose. Importantly, the abstraction hierarchy

model uses means-ends relationships to link nodes across the five levels of abstraction.

Every node in the abstraction hierarchy should be the end that is achieved by all of the

linked nodes below it, and also the means that (either on its own or in combination with

other nodes) can be used to achieve all of the linked nodes above it.


The second phase, Control Task Analysis (ConTA), is used to examine the specific tasks that

are undertaken to achieve the purposes, priorities and values and functions of a particular

work domain (Naikar, Moylan & Pearce, 2006). Rasmussen’s decision ladder (Rasmussen,

1976; cited in Vicente, 1999) and Naikar et al’s (2006) contextual activity template are used

for the ConTA phase. The decision ladder is used to examine the overall decision making

process that can be adopted during different tasks along with the short cuts through this

process that are typically made by users with differing levels of experience and expertise.

The contextual activity template is used to examine to map functions and affordances across

different contexts and locations in terms of where they are currently undertaken and where

they could be given design modifications.

Strategies Analysis


The strategies analysis phase is used to identify each of the ways in which different

functions can be achieved by the range of actors within the system. Building on the ConTA

phase which shows exactly what needs to be done to achieve functions, this phase describes

all of the different ways or strategies through which the control tasks can be undertaken.

The Strategies Analysis Diagram (SAD; Cornelissen et al, 2013) is one approach that can be

used to conduct the strategies analysis phase. This builds on the WDA outputs to examine

the range of strategies available within a given system based on the means ends links

between physical objects, affordances, and functions.

Social Organisation and Co-operation Analysis (SOCA)

The SOCA phase is used to identify how the activity and associated strategies are distributed

amongst human operators and technological artefacts within the system in question, and

also how these actors could potentially communicate and cooperate (Vicente, 1999). The

key contribution of the SOCA phase is to develop an optimum allocation of functions for the

system in question; essentially it looks at who does what, and who could do what – the

important point being that the who can be both humans and non-humans (e.g.

technologies, artefacts). The ultimate objective is to determine how social and technical

factors can work together in a way that enhances system performance (Vicente, 1999). The

SOCA process typically involves using the outputs from the first three phases to identify

what human and non-human actors currently do, and functions, decisions, and strategies

could potentially be allocated.


The four phases described above were used to analyse current rail level crossing systems in

Australia. The aim of the analysis was to generate an in-depth understanding of rail level

crossing systems in order to inform the generation of design requirements for enhancing

safety. The analysis focussed on active rail level crossings. Active rail level crossings have

both ‘active’ warning devices that provide a warning of an approaching train, such as

flashing lights, boom gates and warning bells, along with passive warnings that also provide

a warning of the rail level crossing itself. There are currently around 8,800 rail level crossings

in Australia, with approximately a third being active crossings and two thirds being passive

(i.e. having no ‘active’ warnings) (Australian Transport Council, 2003).

Methodology

Multiple analysts with significant experience in applying CWA in a range of areas (e.g.

defence, road and rail transport, aviation, maritime) were involved in conducting the CWA.

The data used by the analysts to inform the CWA was gathered during the various data

collection activities described below. All activities were granted full ethics approval by the

Monash University Human Research Ethics Committee.

On-road studies of driver behaviour

Two on-road studies of driver behaviour at rail level crossings were undertaken. One

focussed on active crossings in an urban environment and one focussed on both active and

passive crossings in a rural environment. Both studies involved participants driving a pre-

defined route incorporating rail level crossings whilst providing ‘think aloud’ verbal


protocols. The urban study was undertaken in the South-East suburbs of Melbourne and

involved 22 drivers aged XX – XX years (M=XX, SD = XX) negotiating a route incorporating

nine active rail level crossings. The rural crossing study was undertaken in Greater Bendigo,

Victoria, Australia and involved 22 drivers aged XX – XX years (M=XX, SD = XX) negotiating a

route incorporating ten rail level crossings (six were active with five having flashing lights

and boom gates and one having flashing lights only, and four were passive RLXs with three

having a stop sign only and one having with a give way sign only).

Cognitive task analysis interviews with drivers

The on-road studies described above also had a cognitive task analysis interview component

in which each participant was subjected to a Critical Decision Method interview (CDM; Klein

et al, 1989) post drive. The interview focussed on decision making at one of the rail level

crossings encountered on the route and used a series of cognitive probes to interrogate the

road users’ decision making process when negotiating the rail level crossing in question.

Diary study of road user behaviour

A total of 166 participants, aged 18-71 years (M=39.9, SD = 12.9), took part in a diary study

of road user behaviour at rail level crossings in Victoria, Australia. Participants, including

drivers, pedestrians, cyclists and motorcyclists, completed a daily ‘diary’ of all rail level

crossings that they encountered during a two-week period. They were asked to record the

number and types of crossings encountered, whether a train was approaching, and the

types of warnings in use at each crossing. In situations where a train was approaching


and/or the active warnings were operational (i.e. flashing lights, boom barriers), participants

were asked to record the details of one crossing encounter per day, where applicable. A

series of questions based on the CDM cognitive task analysis interview (Klein et al., 1989)

was used to capture information regarding participants’ decision making processes,

including whether and why they stopped or proceeded through the crossing and the types

of information they used to inform their decision.

Train driver focus group and in-cab observations

A focus group was held with 2 train drivers and 1 rail subject matter expert to gather

information regarding train drivers’ behaviour at rail level crossings along with information

regarding their perceptions of other road users behaviour at rail level crossings. Participants

were asked to describe their behaviour on approach to rail level crossings along with the

constraints influencing behaviour. In addition, 3 analysts performed in-cab observations

whereby the observed train drivers dealing with rail level crossings on the metro rail

network in Melbourne, Australia.

Subject Matter Expert workshop

A subject matter expert workshop was used to review and refine the draft WDA outputs.

This involved XX stakeholders from rail and road safety organisations. Active and passive

WDAs were presented, following which stakeholders were given the opportunity to review

and refine them.


Results

Work Domain Analysis

A summary of the active rail level crossing WDA is presented in Figure 1.

Functional Purpose

Values and Priority

Measures

Generalised Functions

Physical Functionality

Physical Objects

Provide access

across rail line

Maintain priority

access for rail traffic

Protect road users

Minimise delays to

rail network

Minimise delays to

road network

Protect rail users

Minimise collisions

Minimise injury & fatalities

Minimise risk

Maximise efficiency

Maximise reliability

Minimise road rule violations

Maximise conformity

with standards

etc

Alert to presence of

crossing

Alert to presence of

train

Behave appropriately

for environment

Maintain traffic flow

System design

Maintain road & rail

user separation

Performance monitoring

and education

Maintain infrastructure

Road and road infrastructure

Rail and rail level crossing infrastructure

Rail level crossing warning devices

Vehicles (road and

rail)

Other infrastructure (e.g. buildings)

Standards, guidelines, and rules

Risk assessment

toolsProcedures Natural

environment

Warn, alert, cue,

prompt

Direct & communicate

Separate, obstruct, prevent

Locomotion

Collect, store,

analyse information

Detection AssessCoordinate, standardise,

optimise

Record, punish

Figure 1. Summary of active rail level crossing work domain analysis

At the functional purpose level six different functional purposes were identified. These

included ‘provide access across rail line’, ‘maintain priority access for rail traffic’, ‘protect

road users’, ‘ protect rail users’, ‘minimise delays to rail network’ and ‘minimise delays to

road network’. A notable point here is the competing nature of some of the functional

purposes identified. For example, maintaining priority access for rail traffic whilst minimising

delays to the road network is difficult to achieve.


The values and priority measures level show the criteria that can be used to assess the

system’s progress towards achieving its functional purposes. Seven core values and

priorities were identified, including minimising collisions, injury and fatalities, risk, and road

rule violations, maximising efficiency and reliability of the crossing, and achieving conformity

with design standards. Notably, it is questionable whether any of these values and priority

measures are currently being satisfactorily achieved in Australia (and indeed worldwide).

Moreover, a key issue lies in the extent to which road and rail organisations collect accurate

data and understand rail level crossing system performance around the values and priority

measures specified. For example, it is questionable whether the road and rail sectors

possess accurate data on the level of risk associated with different rail level crossings, with

existing risk assessment processes attracting criticism in the literature (e.g. Salmon et al,

2013). Similarly, the extent to which they have an accurate picture on the number of road

rule violations and near misses at different rail level crossings is questionable. Although near

miss data is collected from train drivers, road users and pedestrians typically do not have a

mechanism to report near misses. The implication of this level of the WDA is that currently

road and rail organisations do not fully understand the extent to which rail level crossings

are meeting key values and priorities. Moreover, it is questionable whether the appropriate

data systems are in place to generate this understanding.

The generalised functions level shows the functions that need to be achieved for safe and

efficient rail level crossing performance. Here the functions relate specifically to the road

users (i.e. alerting them to the rail level crossing and the presence of a train, ensuring that


they behave appropriately for the environment), separation of road and rail users,

maintaining traffic flow, and then designing, monitoring and maintaining the rail level

crossing environment. A key feature of this level is that various combinations of functions

not being achieved can lead to rail level crossing collisions; there are many ways in which

rail level crossing collisions can occur. For example, the system failing to alert the road user

to the presence of a train represents one failed function that can cause a collision. On the

other hand, all functions could also fail in a way that leads to a collision. A second important

feature of this level is that it shows how functions away from the rail level crossing itself

have a bearing on performance and safety at the crossing. For example, functions such as

‘system design’ and ‘performance monitoring and education’ can conceivably play a role in

creating or indeed preventing rail level crossing collisions even though the function might

occur days, weeks, months, even years before an incident (Salmon et al, 2013). Finally, the

failure of current rail level crossing systems to achieve functions at this level is apparent. For

example, as discussed above, performance monitoring and education is not well supported,

and maintain traffic flow is not well supported in urban environments.

The bottom two levels of the WDA show the physical objects that the system comprises

along with their affordances. At the bottom level, physical objects were grouped into the

following categories: road and road infrastructure (e.g. the road, kerb, lane markings), rail

and rail level crossing infrastructure (e.g. tracks, whistleboard, train detection systems), rail

level crossing warning devices (e.g. flashing lights, early warning signage, rail level crossing

markers), vehicles (e.g. cars, trucks, trains), other infrastructure (e.g. buildings), standards,


guidelines and rules (e.g. road rules, road and rail level crossing design standards), risk

assessment tools (e.g. rail level crossing risk assessment tools), procedures (e.g. safety and

maintenance procedures), and the natural environment (e.g. vegetation, weather

conditions).


When users negotiate rail level crossings the key decision is the stop or go decision, which in

this case is defined as instances where users decide whether they should proceed through

the crossing or stop at the crossing and wait for an approaching train to pass. Despite the

obvious importance of this decision, little is known regarding the information users use to

inform it or how the decision making process differs across different road users (e.g. drivers

versus pedestrians). The ConTA phase involved applying the decision ladder to understand

the stop or go decision from the point of view of different users, including drivers,

pedestrians, cyclists, and motorcyclists. In addition, CATs were developed to explore where

affordances were achieved across different situations (these are not reported in the current

paper).

The decision ladder analysis used the data derived from the multi-road user diary study of

rail level crossing behaviour. One hundred and forty participants provided data surrounding

457 encounters with an approaching train and/or activated warnings. The majority of

encounters (92%) occurred in metropolitan Melbourne at active crossings and only these

results are presented. This included a total of 429 encounters at 80 different crossings by


135 participants: 40 drivers (133 encounters); 33 pedestrians (128 encounters); 31

motorcyclists (86 encounters) and 31 cyclists (82 encounters).

Initially, a generic decision ladder for the ‘stop or go’ decision was populated based on the

data (see Figure 2). This involved taking the data from the diary study and mapping it onto

the appropriate sections of the decision ladder. For example, responses to the question

‘what information did you use to make your decision?’ were added to the ‘Information’

component of the decision ladder. The decision ladder presented in Figure 2 therefore

represents an overview of the possible decision making processes adopted by participants

during the 429 encounters with a train.


Are the lights flashing? Are the boom gates descending or down or up/ascending? Are the bells ringing? Are the ped gates closing/closed? Is there traffic slowing/stopped at the RLX?Are there peds stopped at the RLX?Is there a train coming? How fast is the train going?Where is the train? Which way is the train heading?Where are other road users?What are other road users doing? What are the road conditions?What is my current speed?What is the speed limit?Where is the pedestrian crossing?Is it my train?What is the time?Where am I in relation to RLX?Is there another train (coming the other way)?Where is the RLX?Where are other pedestrians? What are other pedestrians/cyclists doing? What is the status of the traffic lights? Is there space on the other side of the crossing? RLX warning signRoad markings Advanced RLX warning signs, Other information

How long have the lights been flashing?How long have the bells been ringing?How long until the boom gates are fully down?How long until the train will get to the RLX?Has the train already passed?Will it be safe to cross by the time I arrive at the crossing?How long have the boom gates been fully down?How long have the ped gates been closed?Are other road users obstructing my path?How much time do I have to make the decision?Is it safe to go through?How long until the ped gates are fully closed?Can I get around the boom gates?Can I get through/around the ped gates?Do I have time to wait?When will the traffic lights change?

Activation Execute

PROCE-DURE

Planning of procedure

TASK

Predict consequences

Evaluate performance

Diagnose state

INFORM-ATION

Definition of task

SYSTEM STATE

OPTIONS

Safety EfficiencyCompliance Just get throughGet to destinationNo goals

CHOSEN GOAL

Should I proceed through?Should I stop?Should I change path?Should I go around boom gates?Should I go around ped gates?

TARGET STATE

What steps are required to proceed through?What steps are required to stop at RLX?What steps are required to change path?What steps are required to go around booms?What steps are required to go through ped gates?What steps are required to go through red traffic signal and through RLX?

Proceed throughStop at RLXChange pathGo around boomsGo around ped gates?Go through red traffic signal and through RLX

Observe information and data, scanning for

cues

Road user sees RLX (inc markers)Road user sees RLX warning signs at RLX (Railway crossing, stop on red signal)Road user sees advanced RLX warning signsRoad user sees passive ped warning signs (‘Stop when lights are flashing’)Road user sees active ped RLX warning signsRoad user sees RLX road markings Road user sees flashing lightsRoad user sees boom gatesRoad user sees trainRoad user hears trainRoad user feels vibration of trainRoad user notices slowing of traffic/traffic queuingRoad user notices peds queuing (at gates)Road user hears auditory warningRoad user sees ped gates/mazeRoad user sees tracksRoad user sees stationRoad user sees signal boxRoad user sees ped crowd (at station)Road user receives alert from in-vehicle systemRoad user sees personal triggering feature (e.g. vegetation, buildings, general signage)Road user sees yellow hash boxRoad user sees rumble stripsRoad user feels rumble stripsRoad user hears train hornRoad user sees train lights (front and ditch)Road user sees traffic signal (at RLX)Road user feels tactile pedestrian ground surface indicatorsRoad user sees footpath markings (wait here)

ALERT

Proceed throughStop at RLXChange path

Most important piece of information

Boom gates Behaviour other road usersFlashing lightsTraffic lights Where is the train? (see train) Bells ringing?RLX warning signSeeing train Hearing train

SafetyEfficiencyComplianceTo get to destinationTo get through/acrossNo goals

GOALS


Figure 2. Decision ladder for all road users at active rail level crossings


The decision ladder shows that there are a range of different sources of information that

road users and pedestrian use, first, to become aware that a rail level crossing is

approaching (the alert component in Figure 2), and second, to inform their decision to stop

or go at the crossing (the information and system state components in Figure 2). In addition

to expected sources of information, such as signage, flashing lights, boom gates, and the

train itself, interesting information used by participants includes the behaviour of other road

users, own behaviour (such as ‘what is my current speed?’), and personal triggering features

such as vegetation or a house.

When asked what the most important piece of information was in determining whether to

stop or go, participants reported a range of information sources including the boom gates,

the behaviour of other road users, flashing lights, traffic lights, where the train is, ringing

bells, rail level crossing warning sign, and seeing or hearing the train itself. The options

identified by participants as available to them on approach to the crossings included to

proceed through, stop at the crossing, or change path and the goals influencing behaviour

were safety, efficiency, compliance, getting to desired destination, or ‘just to get through’.

The remainder of the decision ladder depicts the procedure required to cross and users

choice of an appropriate procedure. The procedures available included to stop, to proceed

through, to change path (in order to avoid the crossing), to go around the boom gates, to go

around the pedestrian gates, or to pass through the traffic lights and then the crossing.

Compliant versus non-compliant decision making


The generic decision ladder was used to explore differences in users’ decision making

processes by overlaying the behaviour of different road users onto it. For the purposes of

this paper, an interesting comparison is that of compliant and non-compliant users. A

compliant decision represents one where the road user decided to stop or go in compliance

with the rail level crossing warnings. A non-compliant decision represents one where the

road user proceeded through the crossing after the active warnings had commenced

operation.

Out of all recorded crossing interactions, 398 were compliant (130 crossings by 39 drivers,

108 crossings by 33 pedestrians, 84 crossings by 31 motorcyclists, and 76 crossings by 28

cyclists). In the compliant group the primary goal of motorcyclists and pedestrians was

safety (39% in both cases) whereas the primary goal of cyclists and drivers was compliance

(42% and 38.5%).

At the alert level of the decision ladder, about half of all available information sources were

used by all road user groups (flashing lights, booms, bells, traffic queuing, seeing a train, and

road markings). Notable differences were that pedestrians (3.8%) also used the pedestrian

gates as their alert, whilst both pedestrians (1.9%) and cyclists (2.6%) used other

pedestrians and cyclists queuing at the pedestrian gates as an alert to the presence of the

crossings. Motorcyclists (57.1%) and drivers (51.5%) most frequently used flashing lights,

whilst pedestrians and cyclists relied more on the auditory warnings (44.3%, 42.1%).


At the information level (information sought by users to determine the state of the system),

most of information sources from the generic decision ladder were used by participants

across groups to inform their decision making; however, motorcyclists and drivers were

more likely to use the flashing lights than anything else (91.7%, 79.3%) whilst pedestrians

and cyclists relied more on the bells (81%, 67.1%).

A total of 31 crossings, made by 20 participants, fell into the non-compliant category (20

crossings by 11 pedestrians, 6 crossings by 5 cyclists, 3 crossings by 3 drivers and 2 crossings

by 1 motorcyclist). The first thing to note is that, in this data set, pedestrians were much

more likely to violate than other road users. For non-compliant participants efficiency was

reported as the most important goal by 66.7% of drivers, 45% of pedestrians, whilst

efficiency and getting to the destination were reported as most important to motorcyclists

(50% each). Safety, efficiency and getting to the destination were reported to be most

important by cyclists (33.3% each). None of the non-compliant motorcyclists cited safety as

a goal.

There were interesting differences in the alerts used by the non-compliant users. The

motorised users used the flashing lights only, whilst cyclists and pedestrians used more

cues, including auditory warnings (50 % and 45%), seeing the train (16.7% and 15%), boom

gates (16.7% and 5%). In addition 5% of pedestrians also reported using the flashing lights,

seeing the boom gates, hearing the train, noticing pedestrians queuing, seeing the warning

signs, and seeing road markings.


At the information level, a similar pattern was found. Here motorised road users were more

likely to use the flashing lights and booms, whereas pedestrians relied on a much wider

range of information than others, including bells (65%), gates (25%), see a train (40%), hear

a train (20%), other vehicles (10%), other pedestrians and cyclists (40%), warning signs (5%),

road markings (5%) and advanced warning signs (5%), and how far they could see along the

tracks (30%). Cyclists relied on the same information elements as pedestrians, excluding

other road users’ behaviour.

Strategies Analysis

The strategies analysis component followed Cornelissen et al’s (2013) Strategies Analysis

Diagram (SAD) methodology whereby verbs and criteria are added to the WDA in order to

identify the range of strategies possible for different road users in rail level crossing

environments. Example pathways from the resulting SAD are presented in Figure 3.

The SAD generated a number of key insights. First, multiple strategies were identified for

each form of road user. Whilst this is not so surprising, an important element of this was the

similarities in strategies in terms of objects used and functions engaged in. For example,

drivers can receive a warning of an approaching train from multiple sources, including the

train itself, the level crossing warning devices, and the behaviour of other road users. This

points to a high level of redundancy within the system and also the multiple roles of objects

within the system. Second, warnings of the rail level crossing itself (as opposed to warnings


of an approaching train) seem less relevant and appear to be not typically used to inform

decision making by users. This finding questions their use within rail level crossing

environments – particularly warning signage that is situated well before the crossings

themselves. Third, a key omission identified through the SAD is failure to provide specific

information regarding the approaching train. Rather, the information currently presented

and used by road users is mainly generic information in the form of barriers and warnings

(i.e. ‘a train is coming’). It is apparent that a number of the strategies adopted would be

better informed through the provision of more specific information, such as time to arrival,

number of trains approaching, time that user will be delayed at the crossing. Fourth, the

SAD revealed the problem of potential conflicts between users adopting different strategies

whilst negotiating rail level crossings. For example, strategies adopted by one form of user

(e.g. pedestrians crossing via the road) can impede or prevent a strategy for another form of

user (e.g. drivers attempting to cross). Fifth and finally, the physical use of infrastructure by

non-motorised road users was an interesting facet of the different strategies identified. For

example, cyclists use of fencing or the boom gates to support their balance. Interestingly

there are no dedicated facilities to support non-motorised users in tasks such as maintaining

balance and sheltering from rain. This lack of support for comfort may encourage users to

continue through the crossing as it becomes active with an approaching train.


Figure 3. SAD flowchart for urban active rail level crossing

Social Organisation and Cooperation Analysis

The SOCA was achieved by mapping different human and non-human actors onto the WDA,

decision ladder, and contextual activity template to identify how functions, affordances,

decisions and strategies are currently allocated across actors, and also to identify how they

could be in order to identify potential redesign recommendations. The actors considered in

the SOCA phase are presented in Table 2.

Table 2. Actors considered during SOCA.Category ActorsRail user - Train driver

- Train- Track tracks

Road user - Driver- Road- Vehicle

Pedestrians - Pedestrian- Footpath

Detection and alert systems

- Active Warning systems- Signage- Detection systems

Regulators/Authorities - Road regulator- Rail regulator- Rail infrastructure provider- Road infrastructure owner- Government- Police

Train service providers - Train service providerMedia - MediaPhysical infrastructure - Physical infrastructure


An extract of the WDA SOCA for existing rail level crossing systems is presented in Table 3.

This shows which of the actors identified currently contribute to the functional purposes

and functions identified in the WDA. For example, ‘Road user’ (road), ‘Detection and alert

systems’ (warnings), and ‘Regulators/Authorities’ (road and rail infrastructure owners)

currently contribute to the functional purpose ‘Provide access across rail line’. For the

function, ‘Alert to presence of rail level crossing’ the following actors currently contribute:

detection and alert systems (e.g. rail level crossing signage), regulators/authorities (through

providing road and rail infrastructure) and physical infrastructure (the rail level crossing

itself).

An extract of the formative WDA SOCA for rail level crossing systems is presented in Table 4.

This shows which of the actors identified could potentially contribute to the functional

purposes and functions following system redesign. For example, for the function, ‘Alert to

presence of rail level crossing’ the ‘road user’ group has been added since an in-vehicle

display or GPS system could potentially provide a warning of an upcoming rail level crossing.


Table 3. Extract from SOCA WDAFunctional purpose Contributing actors (current system) Functions Contributing actors (current system)Provide access across rail line Road user

Detection and alert systems Regulators/Authorities

Alert to presence of rail level crossing Regulators/Authorities Detection and alert systems Physical infrastructure

Maintain priority access for rail traffic

Detection and alert systems Regulators/Authorities Physical infrastructure

Alert to presence of train Rail user Regulators/Authorities Detection and alert systems

Protect road users Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Media Physical infrastructure

Behave appropriately for environment Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Media

Protect rail users Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Train service providers

Maintain road user and rail separation Rail user Road user Pedestrians Detection and alert systems Physical infrastructure

Minimise delays to road network Regulators/Authorities Detection and alert systems

Maintain road user/rail/pedestrian flow Rail user Road user Pedestrians Detection and alert systems Physical infrastructure

Minimise delays to rail network Regulators/Authorities Detection and alert systems Train service providers

System design Regulators/Authorities Train service providers

System performance monitoring and education

Rail user Regulators/Authorities Train service providers Media


Maintain infrastructure Regulators/Authorities

Table 4. Extract from formative SOCA WDA (new additions on top of Table 3 highlighted in bold)Functional purpose Contributing actors (redesigned

system)Functions Contributing actors (redesigned

system)Provide access across rail line Road user

Detection and alert systems Physical infrastructure

Alert to presence of rail level crossing Road user Regulators/Authorities Detection and alert systems Physical infrastructure

Maintain priority access for rail traffic Detection and alert systems Regulators/Authorities Physical infrastructure

Alert to presence of train Rail user Road user Regulators/Authorities Detection and alert systems

Protect road users Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Train service providers Media Physical infrastructure

Behave appropriately for environment Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Media

Protect rail users Rail user Road user Pedestrians Regulators/Authorities Detection and alert systems Train service providers Physical infrastructure

Maintain road user and rail separation Rail user Road user Pedestrians Detection and alert systems Physical infrastructure

Minimise delays to road network Rail user Regulators/Authorities Detection and alert systems Train service providers

Maintain road user/rail/pedestrian flow Rail user Road user Pedestrians Detection and alert systems Physical infrastructure


Minimise delays to rail network Road user Regulators/Authorities Detection and alert systems Train service providers

System design Regulators/Authorities Train service providers

System performance monitoring and education Rail user Road user Pedestrians Detection and alert systems Regulators/Authorities Train service providers Media

Maintain infrastructure Regulators/Authorities


Overall the SOCA outputs show that there are various opportunities for reallocating

functions within the rail level crossing system and for adding redundancy by increasing the

number of actors performing functions within the system. A noteworthy finding here is that

there is a heavy reliance on non-human and rail level crossing-related actors to achieve

functions (e.g. signage, warnings, barriers, trains), leaving road users such as drivers and

vehicles under utilised.

Discussion

The aim of this article was to present the findings derived from a four phase CWA of rail

level crossings. The analysis represents the first CWA of rail level crossings and provides a

detailed description of the system itself (WDA), how decisions are made at rail level

crossings (decision ladder), what different strategies are available for different users

(strategies analysis), and how different functions, decisions, and tasks are allocated across

human and non-human actors within the system (SOCA). This discussion now turns to the

purpose of the overall research program within which this analysis was undertaken; that is,

according to the CWA of rail level crossing systems, what are the key design requirements

for safer rail level crossings. In turn, the extent to which a systems approach achieves the

much-heralded goal of shedding new light on opportunities for improving rail level crossing

safety is examined.

Issues identified and associated design implications


The CWA analysis identified various key issues regarding rail level crossing performance and

safety. From the WDA it is clear that rail level crossing systems are complex environments

with multiple competing purposes, many values and priorities, and multiple pathways to

failure. Importantly, despite clear values and priorities current systems do not appear to

posses the means to understand performance and the extent to which values and priorities

are being realised.

The implications of the WDA is that change may not only be required at the rail level

crossing itself (e.g. introducing new ways of alerting road users to the presence of a train);

but also that fundamental change may be required at the functional purpose level and that

new systems should be introduced that support the collection of data to enable

stakeholders to understand whether or not values and priority measures are being met. The

presence of competing functional purposes, for example, represents a barrier to

implementing systems focussed purely on improving safety as they may adversely impact

other functional purposes such as those related to efficiency. Systems in which trains slow

or stop at rail level crossings are used in Europe and appear to have a safety benefit (REF);

however, with a strong focus on efficiency at the functional purpose level it is questionable

whether such systems would be entertained in Australia.

The WDA suggests that new data systems may be required, or at least integration of existing

data systems is needed. For example, incident and near miss reporting systems and audit

systems would allow a better understanding of whether values and priorities such as


minimising violations, risk and achieving conformity with standards and guidelines are being

met. Whilst such systems do exist, different systems are often used by different

stakeholders (e.g. rail service providers versus rail authorities) and there is little sharing or

communication of data.

The overriding finding from the ConTA and strategies analyses is that, despite aiming to

achieve the same end, different users negotiate rail level crossings in a wide range of

different ways. Importantly, these differences occur both across user groups (e.g. drivers

versus pedestrians) and within user groups (e.g. drivers). These differences relate to the

sources of information used, the goals pursued, and the courses of action employed. For

example, the highly visual nature of driver behaviour versus the high use of audible

warnings by pedestrians and cyclists represents a key difference in the way in which the

users seek information regarding approaching trains.

A second important finding from the ConTA is the extent to which users, particularly

pedestrians, seek additional information to help determine whether they can beat an

approaching train. The ConTA, for example, showed how non-compliant users (mainly

pedestrians in this sample) use a range of information sources, including the train itself and

its current location when deciding whether to proceed through. On top of this, the

strategies analysis highlighted the fact that much of the rail level crossing warning

infrastructure does not provide specific information about approaching trains (e.g. time to

arrival, speed).


Both findings have interesting design implications, painting a picture of a system that

attempts to restrict the information given to its users, but still provides them with the

flexibility to seek further information that might lead to them violating the crossing

warnings. In relation to design, this raises the difficult issue of flexibility and the level of

information that is provided to users; that is, should new designs aim to reduce flexibility

and constrain users in how they can negotiate rail level crossings? And should they provide

users with more information that should better support decision making but could at the

same time increase risky behaviour (i.e. by telling users how long the train will take to arrive

do designers inadvertently help them decide that they can still beat the train?). Whilst

systems thinking would argue strongly to provide flexibility and high levels of information, it

is apparent that this flexibility may lie at the root of rail level crossing incidents (as users

have a high latitude for behaviour). A second implication of these findings is that there is not

a one size fits all solution that will cover all forms of user; all users need to be considered in

the design of rail level crossing environments. Despite being seemingly obvious, a failure to

consider all forms of road user has been identified as key issue in road design efforts (e.g.

Cornelissen et al, 2013). Integrated rail level crossing design processes, standards and

guidelines that consider different road users and pedestrians together and throughout the

design process are required. In addition, the impact of introducing new systems on all road

users, as opposed to one group alone, needs to be assessed. Again, it is worth noting that

these recommendations hint at the requirement for change outside of the rail level

crossings themselves (e.g. modification of design processes, standards and guidelines)


Finally, the strategies analysis and SOCA demonstrate that there is significant scope for a

more sophisticated allocation of tasks and functions within rail level crossing environments.

In short, the burden for rail level crossing safety should not be placed solely on the crossing

and its infrastructure; there are parts of the rail level crossing system that could be doing

more to improve behaviour, such as vehicles and in-vehicle systems and the infrastructure

surrounding rail level crossings. In addition, the current under utilisation of users was

emphasised; humans, despite being highly adaptive and capable decision makers, are

restricted rather than exploited. Finally, the introduction of new objects away from the rail

level crossing itself was emphasised. One important implication here is that new rail level

crossing designs could exploit existing objects in the system such as vehicles (e.g. in-vehicle

warnings of crossings and trains). A second important implication is that new objects not

related to the rail level crossing itself may provide benefits; for example, shelter for

pedestrians close to rail level crossings may increase the likelihood that they will wait for a

train to pass rather than attempt to cross and beat the train.

Does the systems approach shed new light on the rail level crossing problem?

Over the past few years there have been an increasing number of researchers arguing for a

systems approach to be taken when attempting to improve rail level crossing safety (e.g.

Read et al, 2013; Salmon et al, 2013; Wilson and Norris, 2005). Following the analysis

presented it is worth asking whether the adoption of a systems approach does indeed shed

new light on the rail level crossing problem. Outside of Read et al (2013) the recent rail level


crossing literature is predominantly focussed warning devices, providing important

information regarding their likely effectiveness upon implementation (e.g. Lenne et al, 2011;

Tey et al, 2014). One strength of the systems approach is its explanatory power when

examining behaviour and accidents. Similar to Salmon et al (2013), the present analysis

describes factors outside of the users and crossings themselves that play a role in safety and

accidents. For example, the present analysis highlighted the need to reconsider the

functional purposes that drive rail level crossing design along with the need for better data

systems. These are not factors that would be identified by focussing on warning devices or

indeed just users and the crossing itself. A second strength of the approach lies in

highlighting new parts of the system that could be better utilised to achieve safer

performance, providing avenues outside of traditional warning devices. In this case, for

example, the potential use of vehicles in performing functions that the crossing itself

currently performs was highlighted. Finally, and perhaps its major strength, the systems

approach enables the behaviour of all users to be understood, as opposed to individual user

groups alone. Most studies of rail level crossing behaviour focus on user groups in isolation,

such as drivers (e.g. Lenne et al, 2011) or heavy vehicle drivers (Davey, Wallace, Stenson,

Freeman, 2008), whereas a systems approach such as CWA describes the behaviour of

multiple user groups – in this case drivers, pedestrians, cyclists, and motorcyclists. In turn,

this encourages the development and evaluation of designs that cater for all users, not just

one user group alone.


In closing, it is hoped that further systems analysis and design applications are undertaken,

in the rail level crossing context but also across all transportation areas. Whilst analysis

applications are emerging (e.g. Cornelissen et al, 2013), a key challenge moving forward is to

embed systems analysis and design methodologies within sociotechnical system design

processes (Eason, 2014). To this end, articles describing applications involving systems

thinking-based design studies are recommended.

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