The paper presents a classification and analysis of the results achieved using fuzzy logic to model complex traffic and transportation processes. Fuzzy logic is shown to be a very promising mathematical approach to modeling traffic and transportation processes characterized by subjectivity, ambiguity, uncertainty and imprecision. The basic premises of fuzzy logic systems are presented as well as a detailed analysis of fuzzy logic systems developed to solve various traffic and transportation engineering problems. Emphasis is put on the importance of fuzzy logic systems as universal approximators in solving traffic and transportation problems. Possibilities are shown regarding the further application of fuzzy logic in this field.

Fuzzy logic systems for transportation engineering: the state of the art

Use of various deterioration models in the area of infrastructure management has provided decision makers with a vehicle for predicting future deterioration. This paper presents a methodology for predicting the likelihood that a particular infrastructure system is in a deficient state, using logistic regression models, a special case of linear regression. What distinguishes these two models is that the outcome variable in the logistic regression model is binary or dichotomous and assumes a Bernoulli distribution. The methodology is illustrated in a case study involving the evaluation of the local sewer of Edmonton, Alta., Canada. Variables of age, diameter, material, waste type, and average depth of cover are modeled, using historical data, as factors contributing to deterioration of the sewer network. The outcome of this model does not produce a prediction of condition rating but rather uses historical inspection records to provide decision makers with a means of evaluating sewer sections for the planning of future scheduled inspection, based on the deficiency probability.

Assessment of Infrastructure Inspection Needs Using Logistic Models

In this paper, the provision of bus services along different routes that comprise a public transit network is assessed taking into consideration, the service providers, the users and the societal perspectives. This model is based on Data Envelopment Analysis (DEA) [Charnes, A., Cooper W.W., Rhodes, E., 1978. Measuring the efficiency of decision-making units. European Journal of Operational Research 2, 429–444] and derives from the Network Model in DEA [Fare, R., Grosskopf, S., 2000. Network DEA. Socio-Economic Planning Sciences 34, 35–49] and Goal Programming in DEA [Athanassopoulos, A., 1995. Goal programming and data envelopment analysis (GoDEA) for target-based multi-level planning: allocating central grants to the Greek local authorities. European Journal of Operational Research 87, 535–550]. This proposed approach enables the decision maker not only to optimally allocate resources across the transit network but to achieve targets for societal variables that represent the environment in which the bus services are provided.

Performance evaluation of bus routes: A provider and passenger perspective

Airports represent the epitome of complex systems with multiple stakeholders, multiple jurisdictions and complex interactions between many actors. The large number of existing models that capture different aspects of the airport are a testament to this. However, these existing models do not consider in a systematic sense modelling requirements nor how stakeholders such as airport operators or airlines would make use of these models. This can detrimentally impact on the verification and validation of models and makes the development of extensible and reusable modelling tools difficult. This paper develops from the Concept of Operations (CONOPS) framework a methodology to help structure the review and development of modelling capabilities and usage scenarios. The method is applied to the review of existing airport terminal passenger models. It is found that existing models can be broadly categorised according to four usage scenarios: capacity planning, operational planning and design, security policy and planning, and airport performance review. The models, the performance metrics that they evaluate and their usage scenarios are discussed. It is found that capacity and operational planning models predominantly focus on performance metrics such as waiting time, service time and congestion whereas performance review models attempt to link those to passenger satisfaction outcomes. Security policy models on the other hand focus on probabilistic risk assessment. However, there is an emerging focus on the need to be able to capture trade-offs between multiple criteria such as security and processing time. Based on the CONOPS framework and literature findings, guidance is provided for the development of future airport terminal models.

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A review of models and model usage scenarios for an airport complex system

This report documents a research project that developed a model of mid-block crossing difficulty as perceived by pedestrians Four aspects of the research are reported: research design issues; selection of potential determinants; data collection; and statistical analysis This model was done through a statistical calibration and validation process involving collecting actual site characteristics and stated levels of crossing difficulty by a sample of persons at a sample of sites from Hillsborough and Pinellas counties in Florida For traffic operations applications, this model may be used as a screening tool to determine whether pedestrian mid-block crossing facilities, such as crosswalks or pedestrian signals, may be needed at particular locations For planning purposes, this model has a number of applications

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Pedestrian mid-block crossing difficulty

The literature on transportation level-of-service (LOS) evaluation indicates a strong impetus to move away from a strictly capacity/volume- or time/space-based measure to one that directly incorporates the perception of passengers. The difficulty has been that whereas such quantitative measures are reasonably simple to measure, other LOS attributes related to convenience and comfort are qualitative in nature. Such attributes obviously are better expressed in qualitative terms. A review of the literature indicates that suggested methodologies fail to incorporate directly passengers' service perceptions, as expressed in natural language. The use of fuzzy set theory, particularly linguistic fuzzy set models, as a technique for evaluating transportation LOSs is explored. An approach for evaluating airport passenger services using linguistic variables and fuzzy sets is presented. LOS is conceptualized as a hierarchical service system with subcomponents. An example of the model applied to an evaluation of airport terminal services is presented.

Evaluation of transportation level of service using fuzzy sets

The state of the art in airport terminal design has essentially remained unchanged since the 1970s, relying on the use of detailed simulation together with empirical and statistical formulae for sizing the terminal. Air transport has altered considerably since then, with increased use of air travel for both business and leisure, together with the increased use of ‘hub’ terminals in which the terminal acts as an interchange stop on a journey involving several flights. The use of simulation involves a detailed analysis of the terminal design under one set of conditions. To change the design or operating conditions involves a complete resimulation using the new design parameters which is time consuming and computationally expensive. By using a knowledge based approach, a system can be provided which has the flexibility and speed required to explore the consequences of implementing design decisions in a variety of conditions, together with the ability to use and alter facility sizing methodologies to reflect ...

Knowledge based decision support in airport terminal design

The aviation industry is experiencing intense interest in the safety of handling operations at airports. This is because of the level of risk exposure identified in this area, the exposure of expensive aircraft to such high levels of risk, and the increasingly high cost of ramp accidents. The costs to the industry are becoming unacceptable; a global estimate has been made by Boeing of $2 billion per year to airlines. To minimize these costs and control the level of ramp accidents, an overall ramp safety management system approach is required that involves risk analysis and risk management. Risk analysis involves establishing the organization's risk profile, and risk management encompasses the various measures that can be implemented to minimize accidents, control loss, and transfer risk by insurance on the basis of the identified risk profile of an organization. A systems approach to ground handling risk analysis and a description of a spreadsheet-based model developed at Loughborough University for ramp risk management within an organization, such as an airport, airline, or ground handling agent, are presented. The work has been carried out in response to the demonstrated need of industry to control in a systematic manner rapidly rising ramp accident costs that are currently almost universally treated as an unavoidable cost marginal to the core business.

Ngoe N. Ndoh

Papers

Evaluation of transportation level of service using fuzzy sets

Knowledge based decision support in airport terminal design

Airport Ramp Risk Analysis and Management System