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Ali Akgüngör

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Ali Payidar Akgungor was born in Malatya. He received his B.S. and M.Sc. degrees in Civil Engineering Department from Istanbul Technical University, Istanbul, Turkey in 1989 and 1993, respectively. He earned his Ph.D. in Transportation Engineering from the University of Pittsburgh, USA in 1998. He currently works as a full professor of Civil Engineering Department and teaches transportation courses at Kirikkale University. Dr. Akgungor is also the head of Transportation Division at the University.Additionally, He served as Associate Director of the Graduate School of Engineering

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Papers by Ali Akgüngör

A New Delay Parameter for Variable Traffic Flows at Signalized Intersections

Turkish Journal of Engineering and Environmental Sciences, 2007

Estimation of delay at signalized intersections is a complex process and depends on a number of p... more Estimation of delay at signalized intersections is a complex process and depends on a number of parameters, among which the degree of saturation (x = v/c) is the most important. This paper presents a new methodology for estimating delay parameter k, and proposes an analytical delay model for signalized intersections that considers the variation in traffic flow. Unlike the existing delay models in the literature, the delay parameter k is not a fixed value and is expressed as a function of the degree of saturation. The proposed model is applicable to the entire range of expected operation including highly oversaturated traffic conditions. A comparative study of the proposed model against the existing models was performed to verify the improvements by the proposed model. Later, the TRAF-NETSIM (Traffic Network Simulation) microscopic simulation model was used in the calibration and verification of the new delay model for oversaturated conditions. The simulation was conducted in 3 consecutive time periods to reflect fluctuation in traffic demand. The relationship between the simulated and proposed delay model results were analyzed for 48 different scenarios.

A new delay parameter dependent on variable analysis periods at signalized intersections. part 1: Model development

DOAJ (DOAJ: Directory of Open Access Journals), Mar 1, 2008

Delay is an important factor in the optimization of traffic signals and the determination of the ... more Delay is an important factor in the optimization of traffic signals and the determination of the level of service of a signalized intersection. This paper proposes a methodology and a new formulation to identify the delay parameter in signalized intersection delay models. In this study, the delay parameter is modeled as a function of analysis period instead of a fixed value used by the existing delay models. Therefore, the proposed delay model including new delay parameter can produce more reasonable delay estimations at signalized intersections for variable time periods. A comparative study of the proposed time-dependent model against the existing four different models was performed to present the improvements in this model.

Estimating transportation energy demand in Turkey using the artificial bee colony algorithm

Energy, Mar 1, 2017

 Artificial Bee Colony algorithm is proposed to estimate transportation energy demand of Turkey.... more  Artificial Bee Colony algorithm is proposed to estimate transportation energy demand of Turkey.  Gross domestic product, population and total annual vehicle-km are taken as model parameters.  For transportation energy demand estimations, a linear, an exponential and a quadratic models are developed.

Analytical Delay Models for Signalized Intersections

Ite Journal-institute of Transportation Engineers, Feb 1, 1999

Optimum cycle length models using atom search optimization and grasshopper optimization algorithms

Concurrency and Computation: Practice and Experience, Nov 23, 2021

A fixed‐time traffic control system is widely used to manage the traffic flow at intersections. C... more A fixed‐time traffic control system is widely used to manage the traffic flow at intersections. Cycle length has an important effect on the performance of the fixed‐time control system and the Webster model is widely used in the literature to determine the cycle length. However, when the traffic flow ratio (Y) approaches 1, the Webster model loses its effectiveness and cannot determine the cycle length when Y is above 1. In the scope of this study, it is aimed to develop models that can predict cycle length for all traffic conditions in which are Y ≤ 1 and Y ≥ 1. Two different heuristic algorithms, atom search optimization (ASO) and grasshopper optimization algorithm (GOA) were used in the development of models and the performances of these algorithms were demonstrated. The efficiency of the developed models has been demonstrated by comparing them with both Webster's model and VISTRO optimization program. Models developed in exponential, power, and quadratic forms have been able to predict cycle lengths with lower delay values by showing better performance than Webster and VISTRO. In addition, statistical results show that the ASO approach is more successful than the GOA approach.

Taşıt Emisyonlarının Azaltılmasında Trafik Işıklarının Senkronizasyon Etkisinin Modellenmesi

Politeknik dergisi, Mar 1, 2008

Bu makalede Kırıkkale İli Millet bulvarında yer alan 4 sinyalize kavşak ve 5 cadde dilimi üzerind... more Bu makalede Kırıkkale İli Millet bulvarında yer alan 4 sinyalize kavşak ve 5 cadde dilimi üzerinde; kesikli ve yeşil dalga senaryolarına göre taşıt emisyonlarının değişimi modellenmiştir. Bu amaçla, cadde üzerindeki dilimlerde taşıt sayımları yoluyla trafik hacmi ve seyir hızları bulunmuş, kavşaklarda bekleme süreleri tespit edilmiş ve mevcut kesikli duruma göre taşıt kaynaklı emisyonlar bulunmuştur. Daha sonra yeşil dalga etkisini görmek için 50 km/h sabit hızla seyir halinde ve ışıklı kavşakların birinde bekleme yoluyla emisyonların azalması modellenmiştir. Sonuçta yeşil dalga senaryosunun taşıt emisyonlarını genelde % 77,3 oranında azalttığı görülmüştür. Yeşil dalga senaryosunun; cadde emisyonlarını % 3,0 arttırmasına rağmen, kavşaklardaki; beklemelerde % 80,7 ve kalkışlarda % 77,4 azalma sağlandığı görülmüştür. Yeşil dalga senaryosunun en büyük avantajı, kirleticiler içinde en büyük payı oluşturan CO kirleticisinin % 76,7 oranında düşmesidir.

Meta-Sezgisel Yöntemlerle Sabit Zamanlı Sinyalize Kavşaklar için Optimum Devre Süresi Modeli

El-cezeri, May 31, 2019

Son zamanlarda nüfus ve ekonomideki büyüme karayollarında araç kullanımını arttırmaktadır. Buna b... more Son zamanlarda nüfus ve ekonomideki büyüme karayollarında araç kullanımını arttırmaktadır. Buna bağlı olarak kavşakların kapasitesi giderek yetersiz kalmaktadır. Kavşakların verimsiz çalışmasından dolayı gecikme, yakıt tüketimi, emisyon salınımı artarken sürücü davranışları da olumsuz etkilenmektedir. Optimum devre süresinin doğru tespiti ve sinyal sürelerinin düzenlenmesi ile bu sorunların minimuma indirilebilmesi mümkün olmaktadır. Bu çalışmada Yapay Arı Kolonisi Algoritması (YAKA) kullanılarak optimum devre süresi modelleri geliştirilmiştir. Ayrıca en düşük gecikmeye sahip olan devre sürelerinin belirlenmesinde Diferansiyel Gelişim Algoritmasından (DGA) yararlanılmıştır. Kalibre edilen Webster modeline ilave olarak üstel ve kuadratik formda modeller geliştirilmiştir. Geliştirilen bütün modeller Webster modelinden istatistiksel olarak daha iyi performansa sahip olurken, en iyi performansı da üstel model vermiştir. Bu modellerin özellikle yüksek trafik hacmine sahip trafik durumlarında yetersiz kalan Webster modelinin eksikliğini kapatarak alternatif bir devre süresi tahmin modeli olarak kullanılabileceği görülmüştür.

A Hybrid Traffic Controller System based on Flower Pollination Algorithm and Type-2 Fuzzy Logic Optimized with Crow Search Algorithm for Signalized Intersections

Research Square (Research Square), May 17, 2022

In this study, a hybrid traffic signal control (HTSC) system with phase and time optimization bas... more In this study, a hybrid traffic signal control (HTSC) system with phase and time optimization based on Type-2 Fuzzy Logic which was optimized with Crow Search Algorithm (CSA) and Flower Pollination Algorithm (FPA) approaches, was developed. The performance of this developed hybrid traffic system was demonstrated and its applicability was investigated. The performance of the hybrid system according to nine different traffic conditions and four different intersection geometries was compared with fixed-time traffic controller, signal controller based on the FPA approach and phase optimization (FPA_TSC), and the optimized Type-1 Fuzzy Logic Traffic Controller (Type-1 FL-TSC). The HTSC approach has achieved the best performance with about 32% improvement over the fixed-time traffic controller. The HTSC approach has shown 5% and 6% better performance than the FPA_TSC and Type-1 FL-TSC, respectively. In this way, the new controller is shown to contribute to reduction in emissions and fuel consumption, as well as to the minimization of delays and driver dissatisfaction due to signalization. The HTSC approach can be used as an alternative intersection control method for units responsible for intersection control such as highways and municipalities due to its fast and high performance.

Forecasting highway casualties under the effect of railway development policy in Turkey using artificial neural networks

Neural Computing and Applications, Dec 17, 2011

This study presents forecast of highway casualties in Turkey using nonlinear multiple regression ... more This study presents forecast of highway casualties in Turkey using nonlinear multiple regression (NLMR) and artificial neural network (ANN) approaches. Also, the effect of railway development on highway safety using ANN models was evaluated. Two separate NLMR and ANN models for forecasting the number of accidents (A) and injuries (I) were developed using 27 years of historical data (1980-2006). The first 23 years data were used for training, while the remaining data were utilized for testing. The model parameters include gross national product per capita (GNP-C), numbers of vehicles per thousand people (V-TP), and percentage of highways, railways, and airways usages (TSUP-H, TSUP-R, and TSUP-A, respectively). In the ANN models development, the sigmoid and linear activation functions were employed with feed-forward back propagation algorithm. The performances of the developed NLMR and ANN models were evaluated by means of error measurements including mean absolute percentage error (MAPE), mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R 2). ANN models were used for future estimates because NLMR models produced unreasonably decreasing projections. The number of road accidents and as well as injuries was forecasted until 2020 via different possible scenarios based on (1) taking TSUPs at their current trends with no change in the national transport policy at present, and (2) shifting passenger traffic from highway to railway at given percentages but leaving airway traffic with its current trend. The model results indicate that shifting passenger traffic from the highway system to railway system resulted in a significant decrease on highway casualties in Turkey.

Bulanık Mantık ile Diğer Sinyal Denetim Sistemlerinin Karşılaştırılması: Üç Kollu Sinyalize Kavşak Örneği

El-cezeri, Nov 11, 2015

Son zamanlarda artan nufus ve gelisen ekonomiye bagli olarak Turkiye’de trafik hareketlerinde bir... more Son zamanlarda artan nufus ve gelisen ekonomiye bagli olarak Turkiye’de trafik hareketlerinde bir artis gozlenmistir. Trafikteki bu artis basta buyuk sehirler olmak uzere bircok sehrin kavsak noktalarinda cozulmesi gereken yeni trafik sorunlari ortaya cikarmistir. Geleneksel yontemlerin bu yeni problemleri cozmede yetersiz kalmasindan dolayi trafik kontrolunde yeni yaklasimlarin kullanilmasinin gerekliligi net olarak kabul edilmistir. Bu nedenle gunumuzde bulanik mantik (BM) gibi yaklasimlar kullanilarak kavsak noktalarindaki kontrol sistemleri daha verimli hale getirilmeye calisilmaktadir. Bu calisma iki amaca sahip olup bunlardan birincisi kirmizi isikta bekleme suresini sinirlandiran bulanik mantik tabanli sinyal denetim sistemi (BMT-SDS) gelistirmek ve bu sistemi uc kollu bir es duzey kavsagin kontrolunde test etmek, ikincisi ise elde edilen performans degerlerini tam uyarmali sinyal denetim sistemi (TU-SDS) ve on zamanli sinyal denetim sistemleri (OZ-SDS) ile karsilastirarak gelistirilen BMT-SDS’nin performansini ortaya koymaktir. Gelistirilen BMT-SDS, diger kontrol sistemleri ile dusuk trafik hacminden, yuksek hacim degerine dogru degisen on bes adet trafik hacim durumu ile arac basina dusen ortalama gecikme sureleri kullanilarak karsilattirilmistir. Gelistirilen sistem OZ-SDS ile karsilastirildiginda, BMT-SDS’ in %7,3 ile %65,3 arasinda iyilestirme sagladigi gozlenmistir. Ayrica TU-SDS ile karsilastirildiginda, dusuk hacimlerde yuksek hacimlere gore %60’a varan iyilesmeler gozlenmistir.

Bezier Search Differential Evolution algorithm based estimation models of delay parameter <i>k</i> for signalized intersections

Concurrency and Computation: Practice and Experience, Mar 13, 2022

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Farklı Yöntemler Kullanılarak GeliĢtirilen Trafik Kaza Tahmin Modelleri ve Analizi

International Journal of Engineering Research and, Jan 15, 2010

Optimizing of phase plan, sequence and signal timing based on flower pollination algorithm for signalized intersections

Soft Computing, Nov 22, 2020

The purpose of this study is to develop a control system that optimizes the phase plan, sequence ... more The purpose of this study is to develop a control system that optimizes the phase plan, sequence and signal timing using the flower pollination algorithm (FPA). At the same time, it is aimed to improve the fixed-time control system with the optimum cycle length search approach based on the differential evolution algorithm. The applicability and performances of these two control systems were examined in 15 different traffic situations according to 4 different intersection geometries. Fixed-time and optimized fuzzy logic traffic controller (FLC) developed by Dogan were used as the reference control systems in performance comparison. The optimum cycle length search system can achieve approximately 18% improvement over the fixed-time system, but showed lower performance than the FPA and FLC control systems. The FPA system has proven its applicability by achieving the best performance with about a 30% improvement compared to the fixed-time system and about 3% improvement compared to the FLC system. The FPA approach, which has a fast and effective performance, has been found to be an alternative method for intersection control, and it is foreseen that it can increase the intersection capacity and reduce the negative effects such as delay and fuel consumption.

Comparison of artificial bee colony and flower pollination algorithms in vehicle delay models at signalized intersections

Neural Computing and Applications, Aug 3, 2018

Delay is a significant research topic since it includes indicators such as travel quality, lost t... more Delay is a significant research topic since it includes indicators such as travel quality, lost time and fuel consumption. Furthermore, the delay is used for optimization of traffic control systems and determination of the level of service at signalized intersections. Therefore, researchers have focused on accurate estimation of delay. The objective of this study is to simply and accurately estimate the delay and evaluate the performance of the proposed approaches which are artificial bee colony (ABC) and flower pollination algorithms (FPA). In this study, ABC and FPA have been used to develop different delay models which are linear, semi-quadratic, quadratic and power forms. Analysis period (T), the green ratio (g/ C; effective green to cycle length) and the degree of saturation (x = v/c; volume to capacity) are used as input parameters while developing the models. The results of present models are compared to estimations obtained from analytical models which are Highway Capacity Manual and Australian (Akçelik) delay models. Semi-quadratic form yielded to best results in terms of coefficient of determination (R 2), mean square error and mean absolute error. Additionally, FPA approach showed better performance than ABC approach finding the optimal solution in the lower number of iterations.

Optimizing a fuzzy logic traffic signal controller via the differential evolution algorithm under different traffic scenarios

Simulation, Oct 17, 2016

This study aims at optimizing fuzzy logic controller (FLC) triangle membership functions (MFs) fo... more This study aims at optimizing fuzzy logic controller (FLC) triangle membership functions (MFs) for different traffic volumes via differential evolution (DE). To achieve this goal, a new FLC with a red time limiter, which actually calculates green time and the extension time of traffic movement phase, is developed to control an intersection. Subsequently, this FLC is optimized with two levels, namely Level-1 and Level-2. Level-1 searches each fuzzy class’s minimum and maximum values (α and β) that generate the lowest average delay per vehicle with DE. Using DE Level-2 inherits Level-1 ranges and reshapes the MFs to explore lower delay values computed by Level-1. The proposed method is tested with nine different traffic scenarios. For each scenario, 15 different headways are applied for a four-leg isolated intersection. The results indicate that the intersection average performance is increased up to 52%, 48%, and 14% at 800, 1600, and 2400 veh/h total intersection volumes, respectively, after Level-1 optimizations. They also reveal that intersection control produces higher delay values in only four scenarios after Level-2 procedures. Consequently, it is shown that the DE has significant potential to optimize FLCs at the intersection signal control. In addition, tuning fuzzy class ranges is found to be more critical than the MF reshaping process in traffic control via FLCs.

Flower pollination algorithm approach for the transportation energy demand estimation in Turkey: model development and application

Energy Sources Part B-economics Planning and Policy, Dec 2, 2018

This study proposes a new optimization technique to estimate the Transportation Energy Demand (TE... more This study proposes a new optimization technique to estimate the Transportation Energy Demand (TED) employing the Flower Pollination Algorithm (FPA). The TED estimation models were developed based on three parameters, which are Annual Vehicle-Km (AVK), Gross Domestic Product per Capita (GDPperC), and Carbon-dioxide (CO 2) emission according to the linear, power and quadratic forms. These three parameters were determined by the WEKA data mining software program among nine parameters. Randomly selected 80% of historical data for 47 years, from 1970 to 2016, were used for the training of the algorithm, and the remains were used in the testing stage of the models. The performances of the models were evaluated according to six different statistical criteria. Transportation energy demand forecasts by 2035 were carried out using three different scenarios using the TED estimation models. According to the scenarios, it is predicted that the transportation energy demand in Turkey will have doubled by 2035 in comparison with 2016. The FPA approach has been successfully applied in the development of the TED estimation models. The most important impact of this study is to help the creation of strategic action plans for energy policies in the transport sector and to contribute to the more efficient use of limited energy resources in the country.

Trafik Tıkanıklığının Fiyatlandırılması Ve Uygulamalarının İncelenmesi: Kızılay Ankara Örneği

El-cezeri, Sep 30, 2017

Büyük şehirlere göçün artmasıyla birlikte, nüfus ve araç sahipliğindeki artış şehir merkezlerinde... more Büyük şehirlere göçün artmasıyla birlikte, nüfus ve araç sahipliğindeki artış şehir merkezlerindeki trafik yoğunluğuna ve tıkanıklığa neden olmaktadır. Bu çalışma ile, Ankara'da trafik yoğunluğunun yüksek olduğu Kızılay bölgesinde trafik tıkanıklığının fiyatlandırılmasına yönelik halkın beklenti ve tepkileri ölçülmekte ve uygulanabilecek tahmini trafik tıkanıklık fiyatı anket verileri ile belirlenmeye çalışılmıştır. Bu kapsamda, belirlenen bölgede 400 kişi ile anket uygulaması yapılarak veriler toplanmış ve analiz edilmiştir. Yapılan analizler sonucunda insanların Kızılay bölgesine özel araç girişlerinin fiyatlandırılması uygulamasını istemedikleri ve herhangi bir fiyat uygulamasına gidilmesi durumunda özel araçla bölgeye gelmeyi tercih etmeyecek kişilerin önemli bir oranda olduğu görülmüştür. Yine anket verilerinden elde edilen bir başka sonuç ise toplu taşıma sistemlerinin geliştirilmesi durumunda, halkın büyük bir çoğunluğunun özel araçları yerine toplu taşımayı tercih edecek olmasıdır. Tıkanıklık fiyatının tespit edilmesine yönelik yapılan hesaplamalar sonucunda alt sınır olarak 5 TL, üst sınır olarak 7,15 TL bulunmuştur. Fiyatın uygulanması durumunda anket verileri göz önünde bulundurularak tıkanıklığın belirgin bir oranda azalabileceği değerlendirilmiştir.

An Artificial Intelligent Approach to Traffic Accident Estimation: Model Development and Application

Transport, Jun 30, 2009

This study proposes an Artificial Neural Network (ANN) model and a Genetic Algorithm (GA) model t... more This study proposes an Artificial Neural Network (ANN) model and a Genetic Algorithm (GA) model to estimate the number of accidents (A), fatalities (F) and injuries (I) in Ankara, Turkey, utilizing the data obtained between 1986 and 2005. For model development, the number of vehicles (N), fatalities, injuries, accidents and population (P) were selected as model parameters. In the ANN model, the sigmoid and linear functions were used as activation functions with the feed forward-back propagation algorithm. In the GA approach, two forms of genetic algorithm models including a linear and an exponential form of mathematical expressions were developed. The results of the GA model showed that the exponential model form was suitable to estimate the number of accidents and fatalities while the linear form was the most appropriate for predicting the number of injuries. The best fit model with the lowest mean absolute errors (MAE) between the observed and estimated values is selected for future estimations. The comparison of the model results indicated that the performance of the ANN model was better than that of the GA model. To investigate the performance of the ANN model for future estimations, a fifteen year period from 2006 to 2020 with two possible scenarios was employed. In the first scenario, the annual average growth rates of population and the number of vehicles are assumed to be 2.0 % and 7.5%, respectively. In the second scenario, the average number of vehicles per capita is assumed to reach 0.60, which represents approximately two and a half-fold increase in fifteen years. The results obtained from both scenarios reveal the suitability of the current methods for road safety applications.

Estimation of Passenger-Kilometer and Tonnekilometer Values for Highway Transportation in Turkey Using the Flower Pollination Algorithm

Scientific Journal of Silesian University of Technology. Series Transport, Mar 30, 2018

Within the scope of this study, intercity passenger and freight movements in Turkey are estimated... more Within the scope of this study, intercity passenger and freight movements in Turkey are estimated by using the flower pollination algorithm (FPA), while demand forecasts are performed on transport systems considering possible future scenarios. Since the passenger and freight transport system in Turkey mainly involves road transport, passenger-kilometer and tonne-kilometer values of this system are estimated. By relying on three independent parameters, models were developed in three different forms: linear, force and semi-quadratic. Population (P) between 1990 and 2016, gross domestic product per capita (GDPperC) in US dollars and the number of vehicles were used as input parameters for the development of the models. When the passenger-kilometer models were created, the number of cars, buses and minibuses that are predominantly used for passenger transportation was preferred for the number of vehicles, while the number of trucks and vans used for cargo transportation were taken into consideration in the tonne-kilometer models. The coefficients of the models were determined by FPA optimization, with models developed to estimate passenger-kilometer and tonne-kilometer values. The model results were

The Estimation of Vehicle Ownership via Flower Pollination Algorithm in Turkey

Gazi mühendislik bilimleri dergisi, Apr 30, 2018

A New Delay Parameter for Variable Traffic Flows at Signalized Intersections

Turkish Journal of Engineering and Environmental Sciences, 2007

Estimation of delay at signalized intersections is a complex process and depends on a number of p... more Estimation of delay at signalized intersections is a complex process and depends on a number of parameters, among which the degree of saturation (x = v/c) is the most important. This paper presents a new methodology for estimating delay parameter k, and proposes an analytical delay model for signalized intersections that considers the variation in traffic flow. Unlike the existing delay models in the literature, the delay parameter k is not a fixed value and is expressed as a function of the degree of saturation. The proposed model is applicable to the entire range of expected operation including highly oversaturated traffic conditions. A comparative study of the proposed model against the existing models was performed to verify the improvements by the proposed model. Later, the TRAF-NETSIM (Traffic Network Simulation) microscopic simulation model was used in the calibration and verification of the new delay model for oversaturated conditions. The simulation was conducted in 3 consecutive time periods to reflect fluctuation in traffic demand. The relationship between the simulated and proposed delay model results were analyzed for 48 different scenarios.

A new delay parameter dependent on variable analysis periods at signalized intersections. part 1: Model development

DOAJ (DOAJ: Directory of Open Access Journals), Mar 1, 2008

Delay is an important factor in the optimization of traffic signals and the determination of the ... more Delay is an important factor in the optimization of traffic signals and the determination of the level of service of a signalized intersection. This paper proposes a methodology and a new formulation to identify the delay parameter in signalized intersection delay models. In this study, the delay parameter is modeled as a function of analysis period instead of a fixed value used by the existing delay models. Therefore, the proposed delay model including new delay parameter can produce more reasonable delay estimations at signalized intersections for variable time periods. A comparative study of the proposed time-dependent model against the existing four different models was performed to present the improvements in this model.

Estimating transportation energy demand in Turkey using the artificial bee colony algorithm

Energy, Mar 1, 2017

 Artificial Bee Colony algorithm is proposed to estimate transportation energy demand of Turkey.... more  Artificial Bee Colony algorithm is proposed to estimate transportation energy demand of Turkey.  Gross domestic product, population and total annual vehicle-km are taken as model parameters.  For transportation energy demand estimations, a linear, an exponential and a quadratic models are developed.

Analytical Delay Models for Signalized Intersections

Ite Journal-institute of Transportation Engineers, Feb 1, 1999

Optimum cycle length models using atom search optimization and grasshopper optimization algorithms

Concurrency and Computation: Practice and Experience, Nov 23, 2021

A fixed‐time traffic control system is widely used to manage the traffic flow at intersections. C... more A fixed‐time traffic control system is widely used to manage the traffic flow at intersections. Cycle length has an important effect on the performance of the fixed‐time control system and the Webster model is widely used in the literature to determine the cycle length. However, when the traffic flow ratio (Y) approaches 1, the Webster model loses its effectiveness and cannot determine the cycle length when Y is above 1. In the scope of this study, it is aimed to develop models that can predict cycle length for all traffic conditions in which are Y ≤ 1 and Y ≥ 1. Two different heuristic algorithms, atom search optimization (ASO) and grasshopper optimization algorithm (GOA) were used in the development of models and the performances of these algorithms were demonstrated. The efficiency of the developed models has been demonstrated by comparing them with both Webster's model and VISTRO optimization program. Models developed in exponential, power, and quadratic forms have been able to predict cycle lengths with lower delay values by showing better performance than Webster and VISTRO. In addition, statistical results show that the ASO approach is more successful than the GOA approach.

Taşıt Emisyonlarının Azaltılmasında Trafik Işıklarının Senkronizasyon Etkisinin Modellenmesi

Politeknik dergisi, Mar 1, 2008

Bu makalede Kırıkkale İli Millet bulvarında yer alan 4 sinyalize kavşak ve 5 cadde dilimi üzerind... more Bu makalede Kırıkkale İli Millet bulvarında yer alan 4 sinyalize kavşak ve 5 cadde dilimi üzerinde; kesikli ve yeşil dalga senaryolarına göre taşıt emisyonlarının değişimi modellenmiştir. Bu amaçla, cadde üzerindeki dilimlerde taşıt sayımları yoluyla trafik hacmi ve seyir hızları bulunmuş, kavşaklarda bekleme süreleri tespit edilmiş ve mevcut kesikli duruma göre taşıt kaynaklı emisyonlar bulunmuştur. Daha sonra yeşil dalga etkisini görmek için 50 km/h sabit hızla seyir halinde ve ışıklı kavşakların birinde bekleme yoluyla emisyonların azalması modellenmiştir. Sonuçta yeşil dalga senaryosunun taşıt emisyonlarını genelde % 77,3 oranında azalttığı görülmüştür. Yeşil dalga senaryosunun; cadde emisyonlarını % 3,0 arttırmasına rağmen, kavşaklardaki; beklemelerde % 80,7 ve kalkışlarda % 77,4 azalma sağlandığı görülmüştür. Yeşil dalga senaryosunun en büyük avantajı, kirleticiler içinde en büyük payı oluşturan CO kirleticisinin % 76,7 oranında düşmesidir.

Meta-Sezgisel Yöntemlerle Sabit Zamanlı Sinyalize Kavşaklar için Optimum Devre Süresi Modeli

El-cezeri, May 31, 2019

Son zamanlarda nüfus ve ekonomideki büyüme karayollarında araç kullanımını arttırmaktadır. Buna b... more Son zamanlarda nüfus ve ekonomideki büyüme karayollarında araç kullanımını arttırmaktadır. Buna bağlı olarak kavşakların kapasitesi giderek yetersiz kalmaktadır. Kavşakların verimsiz çalışmasından dolayı gecikme, yakıt tüketimi, emisyon salınımı artarken sürücü davranışları da olumsuz etkilenmektedir. Optimum devre süresinin doğru tespiti ve sinyal sürelerinin düzenlenmesi ile bu sorunların minimuma indirilebilmesi mümkün olmaktadır. Bu çalışmada Yapay Arı Kolonisi Algoritması (YAKA) kullanılarak optimum devre süresi modelleri geliştirilmiştir. Ayrıca en düşük gecikmeye sahip olan devre sürelerinin belirlenmesinde Diferansiyel Gelişim Algoritmasından (DGA) yararlanılmıştır. Kalibre edilen Webster modeline ilave olarak üstel ve kuadratik formda modeller geliştirilmiştir. Geliştirilen bütün modeller Webster modelinden istatistiksel olarak daha iyi performansa sahip olurken, en iyi performansı da üstel model vermiştir. Bu modellerin özellikle yüksek trafik hacmine sahip trafik durumlarında yetersiz kalan Webster modelinin eksikliğini kapatarak alternatif bir devre süresi tahmin modeli olarak kullanılabileceği görülmüştür.

A Hybrid Traffic Controller System based on Flower Pollination Algorithm and Type-2 Fuzzy Logic Optimized with Crow Search Algorithm for Signalized Intersections

Research Square (Research Square), May 17, 2022

In this study, a hybrid traffic signal control (HTSC) system with phase and time optimization bas... more In this study, a hybrid traffic signal control (HTSC) system with phase and time optimization based on Type-2 Fuzzy Logic which was optimized with Crow Search Algorithm (CSA) and Flower Pollination Algorithm (FPA) approaches, was developed. The performance of this developed hybrid traffic system was demonstrated and its applicability was investigated. The performance of the hybrid system according to nine different traffic conditions and four different intersection geometries was compared with fixed-time traffic controller, signal controller based on the FPA approach and phase optimization (FPA_TSC), and the optimized Type-1 Fuzzy Logic Traffic Controller (Type-1 FL-TSC). The HTSC approach has achieved the best performance with about 32% improvement over the fixed-time traffic controller. The HTSC approach has shown 5% and 6% better performance than the FPA_TSC and Type-1 FL-TSC, respectively. In this way, the new controller is shown to contribute to reduction in emissions and fuel consumption, as well as to the minimization of delays and driver dissatisfaction due to signalization. The HTSC approach can be used as an alternative intersection control method for units responsible for intersection control such as highways and municipalities due to its fast and high performance.

Forecasting highway casualties under the effect of railway development policy in Turkey using artificial neural networks

Neural Computing and Applications, Dec 17, 2011

This study presents forecast of highway casualties in Turkey using nonlinear multiple regression ... more This study presents forecast of highway casualties in Turkey using nonlinear multiple regression (NLMR) and artificial neural network (ANN) approaches. Also, the effect of railway development on highway safety using ANN models was evaluated. Two separate NLMR and ANN models for forecasting the number of accidents (A) and injuries (I) were developed using 27 years of historical data (1980-2006). The first 23 years data were used for training, while the remaining data were utilized for testing. The model parameters include gross national product per capita (GNP-C), numbers of vehicles per thousand people (V-TP), and percentage of highways, railways, and airways usages (TSUP-H, TSUP-R, and TSUP-A, respectively). In the ANN models development, the sigmoid and linear activation functions were employed with feed-forward back propagation algorithm. The performances of the developed NLMR and ANN models were evaluated by means of error measurements including mean absolute percentage error (MAPE), mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R 2). ANN models were used for future estimates because NLMR models produced unreasonably decreasing projections. The number of road accidents and as well as injuries was forecasted until 2020 via different possible scenarios based on (1) taking TSUPs at their current trends with no change in the national transport policy at present, and (2) shifting passenger traffic from highway to railway at given percentages but leaving airway traffic with its current trend. The model results indicate that shifting passenger traffic from the highway system to railway system resulted in a significant decrease on highway casualties in Turkey.

Bulanık Mantık ile Diğer Sinyal Denetim Sistemlerinin Karşılaştırılması: Üç Kollu Sinyalize Kavşak Örneği

El-cezeri, Nov 11, 2015

Son zamanlarda artan nufus ve gelisen ekonomiye bagli olarak Turkiye’de trafik hareketlerinde bir... more Son zamanlarda artan nufus ve gelisen ekonomiye bagli olarak Turkiye’de trafik hareketlerinde bir artis gozlenmistir. Trafikteki bu artis basta buyuk sehirler olmak uzere bircok sehrin kavsak noktalarinda cozulmesi gereken yeni trafik sorunlari ortaya cikarmistir. Geleneksel yontemlerin bu yeni problemleri cozmede yetersiz kalmasindan dolayi trafik kontrolunde yeni yaklasimlarin kullanilmasinin gerekliligi net olarak kabul edilmistir. Bu nedenle gunumuzde bulanik mantik (BM) gibi yaklasimlar kullanilarak kavsak noktalarindaki kontrol sistemleri daha verimli hale getirilmeye calisilmaktadir. Bu calisma iki amaca sahip olup bunlardan birincisi kirmizi isikta bekleme suresini sinirlandiran bulanik mantik tabanli sinyal denetim sistemi (BMT-SDS) gelistirmek ve bu sistemi uc kollu bir es duzey kavsagin kontrolunde test etmek, ikincisi ise elde edilen performans degerlerini tam uyarmali sinyal denetim sistemi (TU-SDS) ve on zamanli sinyal denetim sistemleri (OZ-SDS) ile karsilastirarak gelistirilen BMT-SDS’nin performansini ortaya koymaktir. Gelistirilen BMT-SDS, diger kontrol sistemleri ile dusuk trafik hacminden, yuksek hacim degerine dogru degisen on bes adet trafik hacim durumu ile arac basina dusen ortalama gecikme sureleri kullanilarak karsilattirilmistir. Gelistirilen sistem OZ-SDS ile karsilastirildiginda, BMT-SDS’ in %7,3 ile %65,3 arasinda iyilestirme sagladigi gozlenmistir. Ayrica TU-SDS ile karsilastirildiginda, dusuk hacimlerde yuksek hacimlere gore %60’a varan iyilesmeler gozlenmistir.

Bezier Search Differential Evolution algorithm based estimation models of delay parameter <i>k</i> for signalized intersections

Concurrency and Computation: Practice and Experience, Mar 13, 2022

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Farklı Yöntemler Kullanılarak GeliĢtirilen Trafik Kaza Tahmin Modelleri ve Analizi

International Journal of Engineering Research and, Jan 15, 2010

Optimizing of phase plan, sequence and signal timing based on flower pollination algorithm for signalized intersections

Soft Computing, Nov 22, 2020

The purpose of this study is to develop a control system that optimizes the phase plan, sequence ... more The purpose of this study is to develop a control system that optimizes the phase plan, sequence and signal timing using the flower pollination algorithm (FPA). At the same time, it is aimed to improve the fixed-time control system with the optimum cycle length search approach based on the differential evolution algorithm. The applicability and performances of these two control systems were examined in 15 different traffic situations according to 4 different intersection geometries. Fixed-time and optimized fuzzy logic traffic controller (FLC) developed by Dogan were used as the reference control systems in performance comparison. The optimum cycle length search system can achieve approximately 18% improvement over the fixed-time system, but showed lower performance than the FPA and FLC control systems. The FPA system has proven its applicability by achieving the best performance with about a 30% improvement compared to the fixed-time system and about 3% improvement compared to the FLC system. The FPA approach, which has a fast and effective performance, has been found to be an alternative method for intersection control, and it is foreseen that it can increase the intersection capacity and reduce the negative effects such as delay and fuel consumption.

Comparison of artificial bee colony and flower pollination algorithms in vehicle delay models at signalized intersections

Neural Computing and Applications, Aug 3, 2018

Delay is a significant research topic since it includes indicators such as travel quality, lost t... more Delay is a significant research topic since it includes indicators such as travel quality, lost time and fuel consumption. Furthermore, the delay is used for optimization of traffic control systems and determination of the level of service at signalized intersections. Therefore, researchers have focused on accurate estimation of delay. The objective of this study is to simply and accurately estimate the delay and evaluate the performance of the proposed approaches which are artificial bee colony (ABC) and flower pollination algorithms (FPA). In this study, ABC and FPA have been used to develop different delay models which are linear, semi-quadratic, quadratic and power forms. Analysis period (T), the green ratio (g/ C; effective green to cycle length) and the degree of saturation (x = v/c; volume to capacity) are used as input parameters while developing the models. The results of present models are compared to estimations obtained from analytical models which are Highway Capacity Manual and Australian (Akçelik) delay models. Semi-quadratic form yielded to best results in terms of coefficient of determination (R 2), mean square error and mean absolute error. Additionally, FPA approach showed better performance than ABC approach finding the optimal solution in the lower number of iterations.

Optimizing a fuzzy logic traffic signal controller via the differential evolution algorithm under different traffic scenarios

Simulation, Oct 17, 2016

This study aims at optimizing fuzzy logic controller (FLC) triangle membership functions (MFs) fo... more This study aims at optimizing fuzzy logic controller (FLC) triangle membership functions (MFs) for different traffic volumes via differential evolution (DE). To achieve this goal, a new FLC with a red time limiter, which actually calculates green time and the extension time of traffic movement phase, is developed to control an intersection. Subsequently, this FLC is optimized with two levels, namely Level-1 and Level-2. Level-1 searches each fuzzy class’s minimum and maximum values (α and β) that generate the lowest average delay per vehicle with DE. Using DE Level-2 inherits Level-1 ranges and reshapes the MFs to explore lower delay values computed by Level-1. The proposed method is tested with nine different traffic scenarios. For each scenario, 15 different headways are applied for a four-leg isolated intersection. The results indicate that the intersection average performance is increased up to 52%, 48%, and 14% at 800, 1600, and 2400 veh/h total intersection volumes, respectively, after Level-1 optimizations. They also reveal that intersection control produces higher delay values in only four scenarios after Level-2 procedures. Consequently, it is shown that the DE has significant potential to optimize FLCs at the intersection signal control. In addition, tuning fuzzy class ranges is found to be more critical than the MF reshaping process in traffic control via FLCs.

Flower pollination algorithm approach for the transportation energy demand estimation in Turkey: model development and application

Energy Sources Part B-economics Planning and Policy, Dec 2, 2018

This study proposes a new optimization technique to estimate the Transportation Energy Demand (TE... more This study proposes a new optimization technique to estimate the Transportation Energy Demand (TED) employing the Flower Pollination Algorithm (FPA). The TED estimation models were developed based on three parameters, which are Annual Vehicle-Km (AVK), Gross Domestic Product per Capita (GDPperC), and Carbon-dioxide (CO 2) emission according to the linear, power and quadratic forms. These three parameters were determined by the WEKA data mining software program among nine parameters. Randomly selected 80% of historical data for 47 years, from 1970 to 2016, were used for the training of the algorithm, and the remains were used in the testing stage of the models. The performances of the models were evaluated according to six different statistical criteria. Transportation energy demand forecasts by 2035 were carried out using three different scenarios using the TED estimation models. According to the scenarios, it is predicted that the transportation energy demand in Turkey will have doubled by 2035 in comparison with 2016. The FPA approach has been successfully applied in the development of the TED estimation models. The most important impact of this study is to help the creation of strategic action plans for energy policies in the transport sector and to contribute to the more efficient use of limited energy resources in the country.

Trafik Tıkanıklığının Fiyatlandırılması Ve Uygulamalarının İncelenmesi: Kızılay Ankara Örneği

El-cezeri, Sep 30, 2017

Büyük şehirlere göçün artmasıyla birlikte, nüfus ve araç sahipliğindeki artış şehir merkezlerinde... more Büyük şehirlere göçün artmasıyla birlikte, nüfus ve araç sahipliğindeki artış şehir merkezlerindeki trafik yoğunluğuna ve tıkanıklığa neden olmaktadır. Bu çalışma ile, Ankara'da trafik yoğunluğunun yüksek olduğu Kızılay bölgesinde trafik tıkanıklığının fiyatlandırılmasına yönelik halkın beklenti ve tepkileri ölçülmekte ve uygulanabilecek tahmini trafik tıkanıklık fiyatı anket verileri ile belirlenmeye çalışılmıştır. Bu kapsamda, belirlenen bölgede 400 kişi ile anket uygulaması yapılarak veriler toplanmış ve analiz edilmiştir. Yapılan analizler sonucunda insanların Kızılay bölgesine özel araç girişlerinin fiyatlandırılması uygulamasını istemedikleri ve herhangi bir fiyat uygulamasına gidilmesi durumunda özel araçla bölgeye gelmeyi tercih etmeyecek kişilerin önemli bir oranda olduğu görülmüştür. Yine anket verilerinden elde edilen bir başka sonuç ise toplu taşıma sistemlerinin geliştirilmesi durumunda, halkın büyük bir çoğunluğunun özel araçları yerine toplu taşımayı tercih edecek olmasıdır. Tıkanıklık fiyatının tespit edilmesine yönelik yapılan hesaplamalar sonucunda alt sınır olarak 5 TL, üst sınır olarak 7,15 TL bulunmuştur. Fiyatın uygulanması durumunda anket verileri göz önünde bulundurularak tıkanıklığın belirgin bir oranda azalabileceği değerlendirilmiştir.

An Artificial Intelligent Approach to Traffic Accident Estimation: Model Development and Application

Transport, Jun 30, 2009

This study proposes an Artificial Neural Network (ANN) model and a Genetic Algorithm (GA) model t... more This study proposes an Artificial Neural Network (ANN) model and a Genetic Algorithm (GA) model to estimate the number of accidents (A), fatalities (F) and injuries (I) in Ankara, Turkey, utilizing the data obtained between 1986 and 2005. For model development, the number of vehicles (N), fatalities, injuries, accidents and population (P) were selected as model parameters. In the ANN model, the sigmoid and linear functions were used as activation functions with the feed forward-back propagation algorithm. In the GA approach, two forms of genetic algorithm models including a linear and an exponential form of mathematical expressions were developed. The results of the GA model showed that the exponential model form was suitable to estimate the number of accidents and fatalities while the linear form was the most appropriate for predicting the number of injuries. The best fit model with the lowest mean absolute errors (MAE) between the observed and estimated values is selected for future estimations. The comparison of the model results indicated that the performance of the ANN model was better than that of the GA model. To investigate the performance of the ANN model for future estimations, a fifteen year period from 2006 to 2020 with two possible scenarios was employed. In the first scenario, the annual average growth rates of population and the number of vehicles are assumed to be 2.0 % and 7.5%, respectively. In the second scenario, the average number of vehicles per capita is assumed to reach 0.60, which represents approximately two and a half-fold increase in fifteen years. The results obtained from both scenarios reveal the suitability of the current methods for road safety applications.

Estimation of Passenger-Kilometer and Tonnekilometer Values for Highway Transportation in Turkey Using the Flower Pollination Algorithm

Scientific Journal of Silesian University of Technology. Series Transport, Mar 30, 2018

Within the scope of this study, intercity passenger and freight movements in Turkey are estimated... more Within the scope of this study, intercity passenger and freight movements in Turkey are estimated by using the flower pollination algorithm (FPA), while demand forecasts are performed on transport systems considering possible future scenarios. Since the passenger and freight transport system in Turkey mainly involves road transport, passenger-kilometer and tonne-kilometer values of this system are estimated. By relying on three independent parameters, models were developed in three different forms: linear, force and semi-quadratic. Population (P) between 1990 and 2016, gross domestic product per capita (GDPperC) in US dollars and the number of vehicles were used as input parameters for the development of the models. When the passenger-kilometer models were created, the number of cars, buses and minibuses that are predominantly used for passenger transportation was preferred for the number of vehicles, while the number of trucks and vans used for cargo transportation were taken into consideration in the tonne-kilometer models. The coefficients of the models were determined by FPA optimization, with models developed to estimate passenger-kilometer and tonne-kilometer values. The model results were

The Estimation of Vehicle Ownership via Flower Pollination Algorithm in Turkey

Gazi mühendislik bilimleri dergisi, Apr 30, 2018