Browsing by Author "Tortum, Ahmet"

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Analysing Headway Spacing and Calculating Passenger Car Equivalent Values Using Computer Vision and International Dataset
(Sveučiliste U Zagrebu, Fakultet Prometnih Znanosti, 2025) Celik, Burak; Tortum, Ahmet; Cintas, Emre; Ozyer, Baris
Accurate traffic flow data are crucial for effective transportation planning and management. Different vehicle types impact traffic flow variably, requiring distinct passenger car equivalency (PCE) factors for calculating intersection and road capacity. Headway and spacing data are essential to assess traffic density and service level. Conventional data collection methods are time-consuming and often inaccurate. Unlike existing studies, this study employed computer vision to measure mixed traffic stream volume in terms of passenger car equivalent and collect headway-spacing data with high accuracy. The vehicle detection and counting procedures provide the mandatory infrastructure for measuring mixed traffic stream volume and collecting headway and spacing data. Novel approaches were introduced to gather comprehensive traffic data, including passenger car equivalent values, headway, spacing, flow rate, vehicle speed and traffic volume, using a single system. A custom and comprehensive international dataset was collected to analyse these approaches. Our trained model achieved a mean average precision (mAP) of 97.4%, with accuracies of 95% for headway, 93% for spacing and 99% for PCE values. The dataset can be downloaded at https://github.com/burak-celik/atavehicledataset.
An Artificial Neural Network Model for Highway Accident Prediction: A Case Study of Erzurum, Turkey
(Svenciliste U Zagrebu, Fakultet Prometnih Znanosti, 2015) Codur, Muhammed Yasin; Tortum, Ahmet
This study presents an accident prediction model of Erzurum's Highways in Turkey using artificial neural network (ANN) approaches. There are many ANN models for predicting the number of accidents on highways that were developed using 8 years with 7,780 complete accident reports of historical data (2005-2012). The best ANN model was chosen for this task and the model parameters included years, highway sections, section length (km), annual average daily traffic (AADT), the degree of horizontal curvature, the degree of vertical curvature, traffic accidents with heavy vehicles (percentage), and traffic accidents that occurred in summer (percentage). In the ANN model development, the sigmoid activation function was employed with Levenberg-Marquardt algorithm. The performance of the developed ANN model was evaluated by mean square error (MSE), the root mean square error (RMSE), and the coefficient of determination (R-2). The model results indicate that the degree of vertical curvature is the most important parameter that affects the number of accidents on highways.
Bursa'daki Ulaştırma Yatırımlarının Kent-Çevre-Toplum İlişkileri Açısından İncelenmesi
(2022) Ünal, Ahmet; Tortum, Ahmet
Kamu yatırımlarının sektörlere göre dağılımı, ülkelerin ekonomik durumlarının anlaşılmasında önemli bir göstergedir. Gelişmekte olan ülkeler ulaşım, sağlık ve inşaat sektörlerinde yoğun harcamalar yaparken; gelişmiş ülkeler ise sanayi, yazılım, uzay ve havacılık alanlarında çalışmaktadır. Gelişmekte olan ülkeler arasında yer alan Türkiye'de savunma ve askeri sanayi gibi alanlarda mega yatırımlar yapılıyorken ulaştırma alanında da önemli yatırımlar yapılmaktadır. Bursa Türkiye'nin 4. büyük şehri olmasının yanında otomotiv sektörünün de en önemli şehirlerinden biridir. Bursa'nın bu konumundan dolayı son yıllarda ulaşım alanında yapılan mega projelerden (Osman Gazi Köprüsü, İstanbul-Bursa-İzmir karayolu vb.) etkilenen illerden biri olmuştur. Bu projelerin dışında Bursa'da son yıllarda şehir merkezinde de önemli ulaşım yatırımları yapılmıştır. Bu çalışma kapsamında Bursa ilinde son yıllarda yapılan ulaşım yatırımları incelenmiştir. Bu projelerin olumlu ve olumsuz yanları incelenerek kent-çevre-toplum ilişkisi araştırılmıştır.
Comparison of Modern and Conventional Methods at the Entrance and Exit of Tunnels
(City Net Scien Res Ctr Ltd-belgrade, 2018) Alemdar, K. Diler; Kaya, Omer; Kuskapan, Emre; Codur, M. Yasin; Tortum, Ahmet
Turkey has gained importance especially highway transport since 1950. For this reason, the number of vehicles on the highways has rapidly increased and this increase has brought many problems. The most important problem is traffic accidents which cause material and spiritual loss. The Winter conditions that are effective in some regions of the country occur disruptions in highway transportation. Particularly in winter when the temperatures are below 0 degrees C accidents happen due to the snow and icing. Although millions of dollars are spent every year to struggle against snow and icing, existing methods are insufficient. Conventional methods used in the struggle against snow and ice damage to pavements, metal parts, environment, human health and economy of the country. Tunnels are often used because of Turkey's geographical situation. 'Traffic accidents are often seen at the entrance and exit of tunnels, especially during the winter seasons because of snow and icing. In these areas, the ice detection and prevention systems as an application of intelligent transportation system can be used instead of conventional methods to reduce the number of traffic accidents. In this study, it is compared that conventional method with the ice detection and prevention system in terms of advantages and disadvantages.
The Development of Decarbonisation Strategies: A Three-Step Methodology for the Suitable Analysis of Current EVCS Locations Applied to Istanbul, Turkey
(MDPI, 2021) Kaya, Omer; Alemdar, Kadir Diler; Campisi, Tiziana; Tortum, Ahmet; Codur, Merve Kayaci
One of the solutions to reduce environmental emissions is related to the deployment of electric vehicles (EVs) with sustainable energy. In order to be able to increase the number of electric vehicles in circulation, it is important to implement optimal planning and design of the infrastructure, with particular reference to areas equipped with charging stations. The suitable analysis of the location of current electric vehicle charging stations (EVCSs) is the central theme of this document. The research focused on the actual location of the charging stations of five major EVCS companies in the province by selecting Istanbul as the study area. The study was conducted through a three-step approach and specifically (i) the application of the analytical hierarchy process (AHP) method for creating the weights of the 6 main and 18 secondary criteria that influence the location of EVCSs; (ii) a geospatial analysis using GIS considering each criterion and developing the suitability map for the locations of EVCSs, and (iii) application of the technique for order preference by similarity to ideal solution (TOPSIS) to evaluate the location performance of current EVCSs. The results show that the ratio between the most suitable and unsuitable areas for the location of EVCSs in Istanbul and the study area is about 5% and 4%, respectively. The results achieved means of improving sustainable urban planning and laying the basis for an assessment of other areas where EVCSs could be placed.
Electric Car Sharing Stations Site Selection from the Perspective of Sustainability: A GIS-Based Multi-Criteria Decision Making Approach
(Elsevier, 2022) Kaya, Omer; Alemdar, Kadir D.; Atalay, Ahmet; Codur, Muhammed Y.; Tortum, Ahmet
It is undoubtedly that the environmental and economic benefits will increase by integrating electric vehicles, which are the vehicles of the future, with the car-sharing system. The problem of determining the locations of electric vehicle charging stations (EVCS) and service areas of the car-sharing system appear with the integration. Environmental and energy concerns are the biggest driving factor behind electric car-sharing systems. In this study, Geographic Information Systems (GIS) based fuzzy multi-criteria decision making (MCDM) method is proposed for the solution of site selection problems of electric car-sharing stations (ECSS). To do so, a three-step solution methodology is developed: (i) determining 20 sub-criteria and weighting the criteria with fuzzy Analytic Hierarchy Process (f-AHP), (ii) obtaining a suitability map for potential ECSS via GIS, (iii) sorting the performance levels of ECSSs assigned according to the suitability map by Elimination and Choice Translating Reality (ELECTRE). The proposed methodology is applied for Istanbul, a metropolitan city in Turkey as a case study. The results show that the most suitable areas for ECSSs in the European and Anatolian side, Istanbul is an intercontinental city, are the south-east part and south-western part, respectively.
Forecasting the Accident Frequency and Risk Factors: A Case Study of Erzurum, Turkey
(Univ Osijek, Tech Fac, 2022) Sahraei, Mohammad Ali; Codur, Merve Kayaci; Codur, Muhammed Yasin; Tortum, Ahmet
Nowadays, life is intimately associated with transportation, generating several issues on it. Numerous works are available concerning accident prediction techniques depending on independent road and traffic features, while the mix parameters including time, geometry, traffic flow, and weather conditions are still rarely ever taken into consideration. This study aims to predict future accident frequency and the risk factors of traffic accidents. It utilizes the Generalized Linear Model (GLM) and Artificial Neural Networks (ANN) approaches to process and predict traffic data efficiently based on 21500 records of traffic accidents that occurred in Erzurum in Turkey from 2005 to 2019. The results of the comparative evaluation demonstrated that the ANN model outperformed the GLM model. The study revealed that the most effective variable was the number of horizontal curves. The annual average growth rates of accident occurrences based on the ANN.s method are predicted to be 11.22% until 2030.
Genelleştirilmiş Lineer Regresyon ile Erzurum Kuzey Çevre Yolu Kaza Tahmin Modeli
(2013) Çodur, Merve Kayacı; Çodur, Muhammed Yasin; Tortum, Ahmet
Dünya nüfusunun artışına paralel olarak araç sahipliliğinin de artması ile birlikte günlük hayattaki araç trafiği de artmıştır. Bu hareketliliğin beraberinde getirdiği en büyük olumsuzluklardan biri olan trafk kazaları, insanhayatına mal olan ve önemli ölçüde ekonomik kayıplara sebep olan bir olaydır. Bu çalışmada 2005-2010 yıllarıarasında Erzurum Kuzey Çevre Yoluna ait veriler kullanılmıştır. Bu çalışmada karayolu güvenliğinin sağlanmasın- da kazalara neden olan faktörlerin incelenmesi ve bu faktörlerin birbiriyle ilişkilerini içine alan GenelleştirilmişLineer Regresyon tekniği ile kaza tahmin modelinin oluşturulması hedefenmiştir. Sonuç olarak kurulan model vemodele etki eden parametrelerin önem düzeyleri çalışma kapsamında sunulmuştur.
Geographical Information Systems Aided Traffic Accident Analysis Case Study: City of Erzurum North Ring Road
(Scientific Research Center Ltd Belgrade, 2014) Codur, Muhammed Yasin; Atalay, Ahmet; Tortum, Ahmet; Dogru, Ahmet Osgur
The population growth in developing World, technological development and urbanization is directly connected with the systems of transportation. Although transportation sector offers pretty much alternatives nowadays, people heavily prefer to highway transportation mode in the east of Turkey. The studies which have been done for providing road safety decrease traffic accidents. Geographical Information System (GIS) technology has been a popular tool for accident data and analysis of black spots in highways. Many traffic agencies have been using GIS for accident analysis. Accident analysis studies aim at the identification of high rate accident locations and safety deficient areas on the highways. A case study, using GIS aided traffic accident analysis for The North Ring Road of Erzurum/Turkey were developed by using the historical data, between 2005 and 2012. In conclusion, this study focused on the practicability of the GIS with the maps for traffic safety analysis.
Identifying the Most Critical Intersections in Transportation Networks
(Univ Osijek, Tech Fac, 2021) Kuskapan, Emre; Codur, M. Yasin; Tortum, Ahmet
With the increasing population worldwide, the number of vehicles is increasing day by day. This increase also creates different traffic problems. Various analysis methods are developed to solve traffic problems and to better examine the road transport network. Especially with the development of technology and intelligent transportation systems entering our lives, analyses can be made using computer software and programs. In this study; using the social network analysis method, the use of which has increased in the field of transportation in recent years, the highway network structure of Erzurum Province - which consists of district connection roads has been analyzed. While making the analysis, the network structure was examined through five different centrality concepts and the critical sequence of the intersections in the district connection roads was determined. Accuracy percentages of the concepts of centrality were determined by comparing the sequences obtained with the sequences actually applied. Then, it was determined that the most suitable centrality concept for the study was Bonacich Power.
Interdisciplinary Evaluation of Intersection Performances-A Microsimulation-Based MCDA
(MDPI, 2021) Alemdar, Kadir Diler; Tortum, Ahmet; Kaya, Omer; Atalay, Ahmet
Intersections are the most important regions in terms of urban traffic management. The intersection areas on the corridor should be analyzed together for consistency in traffic engineering. To do so, three intersections on the Vatan Street corridor in Istanbul, the most crowded city of Turkey, were examined. Various geometric and signal designs were performed for intersections and the most suitable corridor design was analyzed. The corridor designs were modeled with the PTV VISSIM microsimulation software. The most suitable corridor design was evaluated by using the results obtained from the microsimulation via analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) from multi criteria decision analysis (MCDA) methods. The evaluation criteria in the study are vehicle delay, queue length, stopped delay, stops, travel time, vehicle safety, CO emission, fuel consumption, and construction cost. As a result, the current and the most suitable alternative corridors were compared according to the comparison parameters and up to 80% improvements were observed. Thus, some advantages were obtained in terms of energy, environment, time, and cost.
Site Selection for EVCS in Istanbul by GIS and Multi-Criteria Decision-Making
(Pergamon-Elsevier Science Ltd, 2020) Kaya, Omer; Tortum, Ahmet; Alemdar, Kadir Diler; Codur, M. Yasin
Considering the depletion of fossil fuels and the environmental impact of transport, reducing the use of such fuels is a globally accepted priority. Thus, when moving towards alternative energy types, the first will undoubtedly be electrical energy. In order to accelerate and contribute to this process, electric vehicles (EV) must be preferred over conventional motor vehicles. However, there are various problems associated with the use of EVs, such as range and recharge status. Optimal planning of electric vehicle charging stations (EVCS) is a solution to these problems. For this purpose, parameters affecting EVCS locations have been determined in the paper. Considering these parameters and the current EVCS locations, the most suitable alternative EVCS locations were identified using Geographical Information Systems (GIS). Both the current and alternative EVCS locations were evaluated by Analytic Hierarchy Process (AHP), Preference Ranking Organization Method for Enrichment of Evaluations (PROMETHEE), and VlseKriterijuska Optimizacija I Komoromisno Resenje (VIKOR) from multi-criteria decision-making (MCDM) methods. The results show that, in Istanbul, the southeast of the European side and the southwest of the Anatolian side were most suitable for EVCS.
Türkiye'de Hava Ulaşım Talebinin Arıma Modelleri ile Tahmin Edilmesi
(2014) Çodur, Muhammed Yasin; Gözcü, Oğuzhan; Tortum, Ahmet
Ülkemizdeki ulaşım ağları içerisinde gittikçe önem kazanan ve yaygınlaşan havayolu ulaşımı, dış hatlardiye nitelenen ülkeler arası ulaşımda ilk tercih edilen ulaşım yolu olmasının yanında, iç hatlar diye nitelenenşehirlerarası yolculukta da geçmişe nazaran çok daha fazla ilgi görmekte ve havayolu ulaşımına talep gün geçtikçeartmaktadır. Havayolu ulaşım talebinin bilinmesi, kurumlar ve şirketler için strateji belirleme, fyat politikalarınıoluşturma ve altyapı çalışmaları açısından büyük bir avantaj sağlayacaktır. Bu çalışmada, tek değişkenli zamanserileri analizlerinde kullanılan ARIMA modelleri çerçevesinde, 1991 2008 yılları arasındaki süre zarfında,havayolu ulaşımının kendi dinamiklerinden hareketle 2009 yılı için aylık yolcu sayılarının tahmin edilmesigerçekleştirilmiş ve elde edilen tahminlerin güvenilirliği değerlendirilmiştir.
Urban Road Transport Network Analysis: Machine Learning and Social Network Approaches
(Univ Zilina, 2022) Kuskapan, Emre; Codur, M. Yasin; Tortum, Ahmet; Tesoriere, Giovanni; Campisi, Tiziana
Traffic congestion is one of the most significant problems in urban transportation. It has been increasing, especially in regions close to intersections. Several methods have been developed to reduce the traffic congestion. One of the analysis methods is social network analysis (SNA). This method, which has increased use in transportation, can quickly identify the most central intersections in transportation networks. Improvements to central intersections, identified in a road network structure, speed up the traffic flow across the entire network structure. In this study, the Istanbul highway transportation network has been examined and values for a series of network centrality measures have been calculated using the SNA. The accuracy and error scales of the centrality values were compared using a machine learning algorithm. The Bonacich power centrality has been the best performance. Based on the study results the most central intersections in Istanbul have been determined.