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Reducing the waiting time imposed on the passengers transferring between transit lines has always been a concern for public transport schedulers, as it is a complicated problem by nature. Typically, network-wide minimization of transfer waiting time is a highly complex optimization problem, particularly in the case of dealing with huge transit networks. This problem is unlikely to be solved by exact optimization techniques. This study aims to investigate the capability of two powerful metaheuristic algorithms, genetic algorithms and simulate annealing, in coping with the transfer optimization problem. A mathematical model is presented in this study for minimizing the total transfer waiting time in transit systems. Based on this model, a genetic algorithm and a simulated annealing algorithm are developed and applied to a transit network comprising numerous transfer points. The comparative analysis of the results revealed the ability of the both algorithms in reducing the transfer waiting time although the genetic algorithm could return better results in relatively shorter computation times Refereed/Peer-reviewed

The prediction of road traffic accidents is of importance in locating the most hazardous sites in order to improve the safety management level. Through the comparative analysis of traditional road traffic accident prediction methods, an SCGM (1,1)c?Markov prediction model using the grey system theory and Markov chain theory is constructed. By taking the West, North, and South Terraces of Adelaide in South Australia as a case, training and verifying the prediction model is conducted, and the mean absolute percentage error of the combined prediction model is 2.55% which means a high prediction accuracy being achieved. Then, the predicted crash rates of West, North, and South Terraces, which are 99.50, 59.50, and 18.97 crashes/km, respectively, are resulted by the combined models respectively, with West Terrace shown to be the most hazardous road section. The results indicate that the prediction model can be well applied in road traffic accident prediction with strong engineering practicability. Refereed/Peer-reviewed

© 2017 Periodical Offices of Chang'an University. Publishing services by Elsevier B.V. on behalf of Owner. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)., Signalized metering roundabouts are equipped with advanced loop detectors and traffic signals that can reduce vehicle queuing lengths, especially on the dominant approach, when unbalanced traffic flow conditions occur. At a metering roundabout, changeable queuing lengths and the location of detectors determine signal phase times, which in turn affect queuing length on each approach. To date, most studies have focused on performance comparisons between normal and metered roundabouts, but have failed to evaluate the effect of detector locations on queuing formations. In addition, no guidelines have been developed to enable practitioners to select the appropriate detector location that would lead to optimum roundabout performance. This study, therefore, formulated a numerical model for the estimation of queuing length at a metering roundabout. The model consists of advance vehicle detectors on two approaches and one traffic signal. In order to calibrate and verify the model, queuing lengths were recorded using two drones for the Old Belair Road metering roundabout in Adelaide, South Australia. In order to assess the fitness of the model, an R2 test was conducted, and the results showed that the numerical model can predict queuing lengths on the controlling and metered approaches with up to 83% of R2 value. Moreover, the estimated queuing lengths were compared against those predicted by the software AIMSUN for the same location and under the same conditions. It is expected that the model will assist and guide practitioners in determining the best detector locations for metering roundabouts.

Providing temporal coordination among public transport services is of vital importance in transit planning, as it has direct impacts on the waiting time imposed on transferring passengers. This task, which is widely recognized as schedule synchronization, is highly complicated by nature since it typically leads to a complex combinatorial optimization problem. This study aims to investigate the capability of simulated annealing algorithm in coping with this problem. Anew mathematical programming model is presented for the purpose of minimizing the total transfer waiting time in transit networks. Then, a simulated annealing algorithm is developed and applied to a small-size transit network in order to test the algorithm applicability. The numerical results showed the capability of the algorithm in tackling the transit schedule synchronization problem. Refereed/Peer-reviewed

Methanol as a fuel for vehicle is economy and environmental friendly, compared with gasoline. The development of methanol vehicle conforms to China's goal of achieving sustainable development as it would accelerate energy restructure by reducing the dependence on fossil fuels. However, the promotion of methanol vehicle in China is slow. While the governments in China have offered subsidy to electric vehicles, there is lack of financial incentive for other alternative fuels. Without an integrated subsidy system, manufacturers would be hardly involved. This paper introduces methanol as a fuel for vehicle and proposes an optimal subsidy model based on microeconomic theories. As subsidy policy may also be influenced by other criteria, the development of a logit model which includes the designed subsidy model would be a future research direction. Refereed/Peer-reviewed

Transport planners attempt to design transit facilities to accommodate and influence people’s travel behaviour towards the use of public transport instead of private vehicles. An important aspect of achieving such goal is to identify the demand for trips and travel patterns at various times and locations. Through the use of smart cards as a fare payment system and the ever-increasing popularity of Automatic Data Collection Systems, the investigation of travel pattern for transit users is still a challenging issue because of lack of alighting information in most cities. This paper introduces new data mining techniques to extract the travel behaviour information and passenger’s mobility patterns for transit commuters using smart card data in Adelaide. Results indicate the most transfers occur among train to train and bus to bus followed by transfer between train to bus and bus to train. Although there are various forms of payment systems, this study has shown that the use of the smart card is the most preferred mode of payment. The knowledge of travel pattern will facilitate the design of appropriate public transport routes; which leads to the optimisation of schedules and as a result increase public transport patronage. Refereed/Peer-reviewed

Origin-Destination information is of crucial importance within the transport modelling and planning space as it makes it possible to understand the movement patterns in a particular area of interest, during a particular period of time. Advancements in wireless communications, specifically Bluetooth, made it possible for transport engineers to utilise this technology for traffic data collection, including Origin-Destination data. This paper investigates the Origin-Destination data obtained from the Bluetooth-Based data collection system in Adelaide for the data collected in the years 2014 and 2015. Twenty eight through movements for ten randomly selected intersections were studied. The percentages of through movements calculated based on the data obtained from the Bluetooth-based traffic data collection system were compared against the percentages of through movements calculated based on the data obtained from Manual Turning Movement Surveys. This research suggests that further improvements are required before Bluetooth-based Origin-Destination data can be used for detailed movement analysis. Refereed/Peer-reviewed

Based on an overall consideration of factors affecting road safety evaluations, the Bayesian network theory based on probability risk analysis was applied to the causation analysis of road accidents. By taking Adelaide Central Business District (CBD) in South Australia as a case, the Bayesian network structure was established by integrating K2 algorithm with experts’ knowledge, and Expectation-Maximization algorithm that could process missing data was adopted to conduct the parameter learning in Netica, thereby establishing the Bayesian network model for the causation analysis of road accidents. Then Netica was used to carry out posterior probability reasoning, the most probable explanation, and inferential analysis. The results showed that the Bayesian network model could effectively explore the complex logical relation in road accidents and express the uncertain relation among related variables. The model not only can quantitatively predict the probability of an accident in certain road traffic condition but also can find the key reasons and the most unfavorable state combination which leads to the occurrence of an accident. The results of the study can provide theoretical support for urban road management authorities to thoroughly analyse the induction factors of road accidents and then establish basis in improving the safety performance of the urban road traffic system. Refereed/Peer-reviewed

Traffic flow gating is widely used in traffic signal management during queue spill back situations, under predicted traffic flows and downstream lane closure situations in case of an incident. Single point and multiple points gating are used for efficient traffic signal operations based on traffic flow patterns and network characteristics. The traditional way of using gating is to restrict green time at upstream location or locations where queue spill back would not affect the cross traffic flows at upstream. The purpose of this research is to evaluate the effectiveness of upstream gating at a single point on a complex road network using a micro analytical tool SIDRA. The results indicate that the performance of the overall network did not improve significantly but it improves safety by eliminating queue obstruction for cross traffic. Refereed/Peer-reviewed

Methanol as a fuel for vehicle is economy and environmental friendly, compared with gasoline. The development of methanol vehicle conforms to China's goal of achieving sustainable development as it would accelerate energy restructure by reducing the dependence on fossil fuels. However, the promotion of methanol vehicle in China is slow. While the governments in China have offered subsidy to electric vehicles, there is lack of financial incentive for other alternative fuels. Without an integrated subsidy system, manufacturers would be hardly involved. This paper introduces methanol as a fuel for vehicle and proposes an optimal subsidy model based on microeconomic theories. As subsidy policy may also be influenced by other criteria, the development of a logit model which includes the designed subsidy model would be a future research direction. Refereed/Peer-reviewed

A signal metering roundabout is able to reduce delay times, particularly during peak periods. Over time a number of studies have analyzed and assessed its performance. Since 2011, Korea also has adopted roundabouts as intersection control devices. However, the majority of studies regarding metering roundabouts have focused on one traffic signal metering roundabout only. Furthermore, Korea uses a different roundabout analysis method (the aggregated method, rather then the lane-by-lane method used by Australia and the US) due the shortage of data and history of use in Korea. An accurate analysis of multi-lane roundabouts in Korea is thus limited. This study, therefore, has compared both methods based on the Old Belair road metering roundabout in Adelaide which is operated by two traffic signals and consists of two approach lanes entering and exiting. The results from the analysis showed that the metering roundabout can decrease the delay time of the dominant approach significantly, however, the delay time of other approaches was increased under both models. Moreover, lane-by-lane method showed that the metering roundabout can decrease the total roundabout delay time, whereas the metering roundabout increases the total delay time using the aggregated method, and their difference is approximately 1.7s/ve

Normally, under unbalanced traffic volumes, roundabout metering that operates with traffic signals on one (sub-dominant) approach is used to improve roundabout operating conditions. There are few reports of studies concerning roundabout metering that operates with traffic signals on two approaches. SIDRA INTERSECTION 6 is a widely used intersection evaluation software with a roundabout metering model which allows only one approach to be signalized. This paper reports a study of roundabout metering with signals on two approaches using a SIDRA INTERSECTION 6 network model, representing the roundabout as a four-node network. The model is applied to a real-life case on Old Belair Road in Adelaide for the morning peak period (08:00-09:00 AM). Calibration methods are suggested for this analysis. The results of the analysis indicate that the level of service (LOS) and the delay time on the dominant approach are C and 23.2 seconds.

Temporal coordination of services is a crucial aspect of integration in transit systems as it directly affects the waiting times imposed on transferring passengers. A number of methods have been proposed so far for improving temporal coordination in public transport systems. However, those methods are based on the number of transferring passengers which is often difficult information to collect in practice. This paper presents a novel method for reducing passengers’ transfer waiting time without the need for transfer counts data. First, a quantitative index is developed as a measure of effectiveness for quantifying the level of coordination in transit systems. Then, a transfer optimisation algorithm is proposed for minimising the waiting times incurred by the passengers transferring between public transport services. A genetic algorithm is also developed as the solution technique for this algorithm and several computer programs were created for implementing the algorithm. To test the applicability of this method, Adelaide O-Bahn busway was selected as a case study and its existing timetables were modified using the proposed method. The numerical results of this application revealed a considerable reduction in the passengers’ transfer waiting times over peak and inter-peak periods. This method can be used by transit planners and schedulers for assessing the level of coordination in transit systems, as well as for improving temporal coordination between public transport modes and lines, particularly in the absence of transferring passenger counts. Refereed/Peer-reviewed

Temporal coordination of services, as a crucial aspect of integration in public transport systems, has always been a big concern for transit planners and schedulers. One of the major issues in the way of coordinating transit services is the lack of a robust measure of effectiveness for assessing the quality of temporal coordination in public transport systems. Even though the network-wide summation of transfer waiting times is commonly used as a measure for this purpose, this index is not always calculable particularly when transferring passengers count is unavailable. This paper aims to present a practical method for quantifying the level of temporal coordination in transit systems, even in the absence of transfers count data. In this paper, first the timetable coordination indices proposed in the literature are evaluated and discussed. Then, a quantitative index is mathematically developed based on the actual waiting time incurred by transferring passengers in transit systems. A numerical example is also presented to examine the applicability of the proposed index. The results of this application revealed this index could be reliably used as a measure of effectiveness for assessing the level of coordination between public transport services, as well as for evaluating the impacts of different timetabling scenarios on transit systems integration.

This paper presents a practical method for improving the temporal coordination of public transport services intersecting at transit interchanges. First the waiting time incurred by transferring passengers between transit lines is investigated and formulated in this study. Based on this formulation, a mathematical programming model is developed for minimising the total transfer waiting time at transit interchanges. Thereafter, this optimisation model is improved in order to restrict all feasible waiting times to a predetermined value for the purpose of eliminating long waiting times. A genetic algorithm is also developed in this study in order to solve the proposed optimisation models. The models are applied to a transit network, as a numerical example, for the sake of investigating the impacts of the proposed models. The results revealed noticeable capabilities of the improved model in increasing the coordination of transit services at the interchanges

The Simple Platoon Advancement (SPA) model describes a conceptual Intelligent Transportation System in which vehicles are progressed through signalised intersections under the automatic control of roadside and in-vehicle infrastructure. The objective is to increase the throughput of vehicles by moving the queue as a closely-spaced platoon on the start-of-green. Comparisons of stopline throughput are made between the SPA model and a valid representation of current road traffic behaviour. The paper contains a description of a basic model—the homogeneous SPA model with constant acceleration—where all vehicles behave the same in terms of their acceleration characteristics, the time headway they desire and the target speed each is trying to reach after passing through the intersection. The acceleration characteristics in question are the rate and the style: that of this model has no smoothing effect and is instantaneously wrought on a vehicle. Though this is somewhat unrealistic for a working system, the constant acceleration model serves as a yardstick for which to check and compare the development of future models. The framework for this model is defined to enable calculations of measurable goals such as stopline throughput for comparison with the EQD model of current road traffic behaviour. In terms of throughput, the homogeneous SPA model shows that even with a very cautious approach using conservative parameter values, the number of vehicles that would pass the stopline of a SPA-equipped intersection is a little more than 150% compared with the throughput found in today’s road systems. Reductions in jam spacing increase the throughput still further.

Synchronisation of timetables is a vital aspect of integration in public transport systems. Due to its importance, the schedule synchronisation has drawn the attention of researchers over the past years and various methods and models have been developed in this regard. Despite the diversity of the approaches and the models, few research attempts have been dedicated to comparing these methods and their fundamentals. This paper aims to present an insight into the transit schedule synchronisation and its different aspects. The existing approaches for the schedule synchronisation are compared and the current gaps and deficiencies in this domain are discussed in detail in this study. Refereed/Peer-reviewed

Ramp metering is an effective strategy used to manage highway traffic by regulating the on-ramp traffic flow in order to avoid traffic congestion on highway networks. This study aims to investigate the impacts of fixed-time ramp metering on operational characteristics of highway networks via microscopic simulation. A fixed-time ramp meter is modelled for a highway section using Aimsun micro simulator and the traffic condition is evaluated under two ramp control scenarios: no-control and time-of-day metering plan. Three metering plans including one-car-per green, 2-vehicle-platoon releasing and 3-vehicle-platoon releasing are developed for peak and off-peak periods. The results show that ramp metering improves the highway performance, especially at peak hour. However, it leads to serious issues for the ramp and consequently for the entire system. Refereed/Peer-reviewed

Cities around the world are confronted with a great challenge from the rapid growth of urban freight distribution that has resulted in numerous adverse impacts. Goods movement plays a fundamental role in urban economic and social development. Therefore, the urban area as a centre of commercial and social activities, a place to work and live requires reliable and efficient freight transport systems to sustain it. Transport policy making is becoming more complicated as there are multiple factors and stakeholders with different and sometimes conflicting objectives to consider. This is not an easy task to implement transport policy as well as equally satisfy all stakeholders. A more inclusive evaluation tool that enables dealing with such a complex urban environment is necessary to assist decision makers in making such decisions. The aim of this paper is to discuss an ongoing research on the development of an evaluation model for prioritising and selection of last kilometre urban freight distribution initiatives. This paper presents part of the research on the findings from investigation of the study area, retailer survey and the proposed conceptual framework. An overview of urban freight distribution will be briefly introduced. The case study of the Rundle Mall Precinct in Adelaide and preliminary findings from retailer survey will be discussed. Next, the policy evaluation of sustainable urban freight distribution and different methods will be elaborated and the proposed sustainable urban freight distribution evaluation framework will be presented. Refereed/Peer-reviewed

It is now widely accepted that public transport is a critical element in urban planning. Considering the substantial growth in the number of private cars and their negative side effects in developing countries over the recent years, development of public transport has drawn the attention of policy makers and led to introducing new strategies and policy instruments in some of those countries to enhance public transportation. Similarly in Iran, a national policy package was legislated in 2008 in order to direct the resources and efforts to this target. This paper aims to evaluate this policy package and investigate its impacts on the public transport systems in Iran over the recent years. The process of developing this policy package, as well as its aspects and objectives are presented in this paper. Furthermore, this paper discusses whether this policy package has been successful in achieving the intended objectives and highlights the existing obstacles and deficiencies in the way of implementing this policy package. Refereed/Peer-reviewed

Traffic flows are widely employed as a primary input in calculation of control variables including phase splits and cycle lengths for traffic signals. Flow characteristics normally vary in different locations and over time corresponding to different driver behaviours. The examination of traffic flows should provide better understanding of a study area and could move us towards an improved control model. This study analyses traffic flow data extracted from an existing adaptive control system (SCATS: Sydney Coordinated Adaptive Traffic System) in the Adelaide city centre in order to examine data characteristics and look for a suitable modelling approach and level of detail for the analysis. The system primarily measures traffic data using stop-line detectors and records the traffic flows in five-minute intervals. Morning peak period data at five intersections on King William Street were investigated using two analytical approaches: lane-by-lane analysis and approach-based analysis initially by sequential plots. The data shows the periodic nature of the flows. Being periodic, time series analysis has been introduced as an alternative analysis technique using spectral density function (SPF) and auto correlation function (ACF) plots. The results show that this technique can differentiate batch traffic counts from different lane configurations by different shapes of the ACF and this could lead to an appropriate forecasting model for traffic flow. In addition, the different data characteristics indicated by this analysis technique between different lanes suggest that a flow model could be considered at the lane-by-lane level. Refereed/Peer-reviewed

In South Australia, pedestrian accidents denote a significant amount of all road crash categories and are also likely to be the most serious of all accident types. This study will examine reports on pedestrian accidents in the Central Business District (CBD) of Adelaide where 1,138 cases were recorded between 1996 and 2008. In this paper the main characteristics of pedestrian accidents will be analysed: the trends, locations, possible causes and severity level of pedestrian accidents. Analysis results showed that pedestrian accidents usually occurred in winter seasons, morning and afternoon peak hours. It was also noticed that more pedestrian accidents were on 60 km/h roads or divided roads or without traffic controls. Moreover, the most common error of pedestrian accidents was pedestrian/driver inattentions. Finally, several countermeasures to address pedestrian accidents will be recommended which are traffic signals, separated road use and law enforcement.

A study of traffic at a signalised intersection under high throughputs should gain better understanding on traffic characteristics and direct to better management strategies for city traffic during peak periods. This study explores an analysis approach by applying restricted stop-line counts under high throughputs from the existing system as inputs based on analytical model to evaluate operation performance of an intersection. Adopting the analytical model in optimisation, the preliminary findings shows the different levels in degrees of saturation leading to distinct interpretations of that between the adaptive system and the analytical model, which might be the results from the detector positions of input volumes, the variations in cycle lengths and the difference of algorithms. Further study in the correlation of the degrees of saturation as the performance measure calculated by the adaptive system and the analytical model via controlling signal timing in the model could provide better comparable values. Refereed/Peer-reviewed

Despite its successful applications in mode choice modelling, the Neural Network (NN) Approach is often seen as a poor technique for trip distribution estimation. However, empirical results from this study show that the NN can also be used as a good trip distribution modelling tool, by using appropriate Training Algorithm (TA), which is the most critical property of NN. This study will describe the results of NN approach in work trip distribution estimation with three different TAs, namely Back Propagation (BP), Variable Learning Rate (VLR), and Levenberg-Marquardt (LM). The experiments were conducted 30 times for each TA. The results suggest that both BP and VLR models tend to have overestimated total trip numbers, while LM model generates the closest total trip number to the observed one, with less than five per cent difference. Statistical analysis also suggests that LM model is able to generate a consistent performance, while other models have a great fluctuation. Then, the findings from this study are expected can be used as an important consideration for using NN approach as an alternative simple and robust travel demand modelling tool. Refereed/Peer-reviewed

This paper investigates the fundamental features and relationships of vehicle ownership, vehicle expenses and household socio-economic attributes in a mid-sized city in Thailand, using household vehicle ownership data recently collected. In this study, private vehicle dependency is explored. Based on a broad analysis, household income is found to be an important factor associated with both car and motorcycle ownerships, but perform in different manners. An analysis of household vehicle expense shows that the amount of car expense is considerably larger than motorcycle's, while total vehicle expense also takes a significant portion within the household income. Moreover, over three quarters of total vehicle expense in the study area is on fuel. At the end of discussion, several predictions and suggestions on vehicle ownership situation in the study area, including a debate regarding feasibility of introducing price mechanisms for controlling vehicle ownership and usage in the study area, are concluded. Refereed/Peer-reviewed

A study of traffic at a signalised intersection under high throughputs should gain better understanding on traffic characteristics and direct to better management strategies for city traffic during peak periods. This study explores an analysis approach by applying restricted stop-line counts under high throughputs from the existing system as inputs based on analytical model to evaluate operation performance of an intersection. Adopting the analytical model in optimisation, the preliminary findings shows the different levels in degrees of saturation leading to distinct interpretations of that between the adaptive system and the analytical model, which might be the difference of algorithms. Further study in the correlation of the degrees of saturation as the performance measure calculated by the adaptive system and the analytical model via controlling signal timing in the model could provide better comparable values.

The previous studies suggest that the Neural Network (NN) approach is able to model the commodity, migration and work trip flows. However, its generalization performance is poor, compared to the well known doubly constrained gravity model. This paper is intended to fix the testing performance of NN by training the models with the Levenberg-Marquardt (LM) algorithm, while the previous studies used standard Back propagation (BP), Quickprop and Variable Learning Rate (VLR) algorithms. The main difference between those algorithms is the technique used in defining the optimum connection weights. Then, the trained and validated model is used to forecast trip numbers from different Trip production and Trip Attraction dataset. The testing results suggest that the Root Mean Square Error (RMSE) are 168, 152 and 125 for model trained with BP, VLR and LM respectively, while the R2 values are 0.194 0.315, 0.505. The models trained by using BP and VLR have underestimate of forecasted total trip numbers, while the LM algorithm has slightly higher numbers. The same data set is then calibrated by using Hyman's technique for the doubly constrained gravity model. The testing RMSE and R2 for gravity model is 127 and 0.507 respectively. It means the NN model has about the same level of error and goodness of fit as the gravity model, for testing level. Based on these results from this study, it can be concluded that the testing performance of NN approach can be refined to the same level as doubly constrained gravity model when the model is trained by LM algorithm. Refereed/Peer-reviewed

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This paper provides a preliminary analysis ofthe nature of vehicle ownership in mid-sized cities of Thailand using Khon Kaen City as the principal study area. Potentially important factors are examined using an econometric method based on the Khon Kaen Daily Travel Survey 2007 (KKDTS07) database. Models of car and motorcycle ownerships in the study area are presented. Some differences and similarities between the characteristics of car and motorcycle ownership were found. Recommendations are given for further research leading to a more comprehensive understanding of car and motorcycle ownership in mid-sized cities in Thailand and in Southeast Asia Refereed/Peer-reviewed

The Neural Network (NN) approach performance as a fully constraint spatial movement modelling tool is dependent upon its multi properties, like the training algorithm (TA). There is still lack of empirical study regarding the performance of this artificial intelligent approach toward that property, especially in commodity flow distribution. It needs to be carefully selected; otherwise, it will negatively impact the NN model performance. It was reported that the NN model performance tends to be low and inconsistent. It was unable to satisfy the Production and Attraction constraints. This paper reports the NN approach application for commodity flow distribution modelling based on US 2007 Commodity Flow Survey. Three different TAs, namely Back Propagation (BP), Variable Learning Rate (VLR), and Lavemberg-Marquardt (LM), are used in the mapping process. It is found that the NN model trained with LM algorithm can estimate the commodity flow with a consistent performance and a lower epoch number than other algorithms as confirmed by 30 experiments for each TA. It can satisfy both Production and Attraction constraints. It also has the lowest error in term of Mean Squared Error (MSE). Thus, NN approach is proposed as a robust technique for commodity flow distribution modelling

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This paper presents a holistic approach in level crossing safety modelling through the use of Petri nets. A Petri net is capable of dealing with multiple sequences which involve hardware, software and human failures in complex systems. This paper begins with the motivation towards the new modelling approach assessing safety risks in a level crossing. Researches around the world related with level crossing safety risks were first reviewed and highlighted. The paper then presented the research methods, safety modelling and analysis used in the study.II-tool, which is based on the Petri nets approach, was used to build the model. The model was tested at ten critical level crossing locations in South Australia. The first model was developed using the signal failure as the accident mechanism. Results show that the rate of potential accident occurrence at selected locations is very close to the actual rate of accidents. The II-tool appears to be a suitable tool for assessing safety and performance at level crossings. Refereed/Peer-reviewed