Hakan Guler

Decision Support System for Railway Track Maintenance and Renewal Management

This paper describes a decision support system approach for railway track maintenance and renewal management system to analyze the track components and to suggest methods for helping the track managers and engineers decide when maintenance is necessary and when is the best time for renewal. In this study, interviews with track maintenance experts, a national survey, and a comprehensive literature survey were used to develop the proposed decision support system. The developed decision support system includes some decision rules. On the basis of these decision rules, the analyses were realized into some stages: first stage, second stage, coherence stage, optimization stage, and evaluation stage. The developed system analyzed the track with its rich database including decision rules developed by the track specialist professionals and finally successful results were obtained. The developed decision support system proved that it is possible to develop planned maintenance and renewal management systems by using advanced computer and measuring systems instead of corrective maintenance and renewal.

Prediction of railway track geometry deterioration using artificial neural networks: a case study for Turkish state railways

The main goal of this paper is to model track geometry deterioration using a comprehensive field investigation gathered over a period of 2 years on approximately 180 km of railway line. Artificial neural networks (ANNs) were adapted for this research. The railway line was divided into analytical segments (ASs). For each AS, the following data were collected: track structure, traffic characteristics, track layout, environmental factors, track geometry, and maintenance and renewal data. ANN models were developed for the main track geometry parameters and produced significant relationships between the variables. In addition, sensitivity analyses were performed to compute the importance of each predictor in determining the neural network. The obtained results proved that ANN may be an alternative method for predicting track geometry deterioration.

The application of modern GIS technology in the development of railway asset management systems

The assets that consist of railway track components and facilities must be managed by using appropriate management systems such as asset management systems (AMS). In recent years, modern railway technologies which are recording vehicles, remote sensing technologies (airborne photo, airborne laser) and Global Positioning System enable managers to store huge amounts of data precisely and combining them with Geographical Information Systems (GIS) makes AMS very powerful. This paper discusses modern technologies and some GIS applications to railway assets, stations, segments, traffic accidents, maintenance and renewal works (M&R), and railway operations (freight and passenger) in Turkish State Railways.

Track degradation analysis in the scope of railway infrastructure maintenance management systems

Stanje elemenata željeznicke infrastrukture kljucni je faktor koji utjece na sigurnost prometa, raspoloživost infrastrukture, ukupne troskove radova na održavanju i remontu, kao i prihode. Mjerenje i analiza stanja elemenata željeznicke infrastrukture je jedini ispravan pristup kako bi se na ucinkovit nacin pratilo njihovo ponasanje te planirali radovi na održavanju. U radu se opisuje optimalna struktura sustava za upravljanje održavanjem željeznicke infrastrukture (Railway Maintenance Management System RMMS) s posebnim osvrtom na primjenu modela degradacije kao jednog od kljucnih dijelova RMMS-a.

Model to Estimate Trip Distribution: Case Study of the Marmaray Project in Turkey

Istanbul, the only city that straddles two continents, Europe and Asia, is one of the biggest metropolitan areas in the world with over thirteen million residents. The demand for transportation in Istanbul has been boosted considerably due to the increasing population and rising vehicle ownership. On the other hand, the transportation infrastructure has not been developing sufficiently to meet this demand. Hence, the Turkish government and local authorities sought various alternatives to the road transportation system in Istanbul and came up with the Marmaray Project, which was planned and designed to serve both intraurban and interurban passengers and freight transport. One of the main aims of the Marmaray Project is to shift the traffic demand from roads to the rail network. In this paper, a travel demand modeling framework was developed to calculate the transportation demand of the Marmaray corridor. In addition, a model including empirical modeling methods was developed for the highways to estimate the origin and destination matrices. The developed model was used to estimate freight and passenger transportation between Istanbul and other Turkish provinces. The estimated transportation demand results were used to calculate the required train numbers on a daily basis through the Marmaray corridor and some suggestions were put forward to increase the capacity of this corridor.

An empirical modelling framework for forecasting freight transportation

This paper presents a framework which includes empirical modelling methods to estimate freight transportation between defined zones. In this method, observed origin and destination matrices for each type of freight are constituted based on the link counts and the roadside truck survey data. The gravity method is selected to estimate origin and destination matrices by using observed link flows, gross domestic product by provinces and interzonal distances. Advanced statistical techniques and regression analyses are used to estimate the coefficients of the gravity method. The final freight transportation matrix is calibrated with the link flows data by using iterative techniques. The developed method was applied to find the origin and destination matrix of the total freight transportation in Turkey and successful results were obtained.

Line Planning on Path Networks with Application to the Istanbul Metrobüs

Bus rapid transit systems in developing and newly industrialized countries often consist of a trunk with a path topology. On this trunk, several overlapping lines are operated which provide direct connections. The demand varies heavily over the day, with morning and afternoon peaks typically in reverse directions. We propose an integer programming model for this problem, derive a structural property of line plans in the static (or single period) “unimodal demand” case, and consider approaches to the solution of the multi-period version that rely on clustering the demand into peak and off-peak service periods. An application to the Metrobus system of Istanbul is discussed.