Comparison of pavement surface texture determination by sand patch test and 3D laser scanning

A modern highway must be capable of proving traffic safety, comfort to passengers as well as efficient and economical transportation. In view of the increase in the number of traffic accidents due to the developments in automotive industry, the traffic safety has gathered too much consideration in recent years. Skid resistance, on which road safety depends, is closely related to the pavement surface texture. The deterioration due to the traffic loads, especially polishing effect, involves a change in surface texture. In recent years, efforts are needed to develop more advanced technologies for evaluating pavement surface texture. In this study, the 3D laser scanner was utilized to quantify the mean profile depth (MPD) of a pavement at a static location. The surface texture of asphalt concrete pavements was scanned at 31 different locations and the results have been compared with the results of sand patch test. It was found that there is a good correlation between MPD as measured by 3D laser scanning and the m ean texture depth (MTD) as measured by volumetric method (sand patch test)

USE OF COWAN M3 DISTRIBUTION IN MODELLING TRAFFIC FLOW

Uzun yıllar boyunca trafik mühendisleri, trafik akımlarının karakteristiklerini modellemenin yollarını aramışlardır. Bu amaçla kullanılan yöntemlerden birisi, istatistiksel metotlarla, elde edilen verilerin değerlendirilmesidir. Ancak burada karşılaşılan en önemli sorun, verileri tanımlayan ve kolay uygulanabilir bir dağılımın kullanılmasıdır. Cowan M3 dağılımı, bu özellikleri büyük oranda karşılaması nedeniyle dünyada trafik akımlarının modellenmesinde kullanılmaktadır. Çalışmada, bu amaçla Cowan tarafından geliştirilmiş olan ve dünyada özellikle dönel kavşak içinde dönen akımların arasındaki zaman cinsinden aralıkların tanımlanmasında kullanılan Cowan M3 dağılımı tanıtılmaya çalışılmış ve bir veri grubu üzerinde denenerek; geçerliliği araştırılmıştır (Cowan, 1975). For long years traffic engineers try to find a way to model traffic flow characteristics. One of the methods used for this purpose is evaluating the obtained data by using statistical methods. However, the most important problem is to find a distribution that defines the data properly and also can be applied very easily. Because it meets these properties Cowan M3 distribution is widely used in modeling traffic flows. In this study, the distribution, which is developed by Cowan (1975) and mostly used to define the headways between the turning vehicles at roundabouts, is tried to be introduced and its validity is investigated by using real data

Investigating the driver’s response time at signalized intersections

It is generally accepted that, behavioural variables may show differences in different countries, and sometimes in different regions depending on cultural and other socio-economic factors. In literature, several researchers have emphasized that performance of signalized intersections is highly related with drivers’ behaviour. However, only a few parameters can be used to reflect drivers’ behaviour in performance analysis. Start response time is used as a key parameter in calibration of analytical and simulation models. In this study, a detailed analysis is conducted on the variability of start response time with respect to parameters like those that manoeuvre type, cycle time, gender of drivers’, etc. by using data obtained from signalized intersections in İzmir, Turkey. Analysis showed that left and right turning drivers have slightly shorter start response times than all through passing vehicles. In addition, the effect of start response time on base saturation flow is discussed. First published online 14 November 2016

Start-up Lost Time and its Effect on Signalized Intersections in Turkey

Start-up lost time is an important parameter in performance of signalized intersections which may in turn depict the effect of behaviour of different drivers for different countries. In this study the parameters affecting the startup lost time in Turkey will be defined and a model will be established to present the relationship between start-up lost time, saturation flow as well as start response time with the behaviour of Turkish drivers. For this purpose, observations were carried out at eight intersections in Turkey. Analyses have shown that saturation headways decrease with the increase in time in start response since the drivers in the 2nd and higher rows of a queue have a longer time to get prepared to discharge. Results also indicated that start-up lost time increases rapidly as cycle time increases, and lower start-up lost time values can be observed in left or right turning lanes.</p

THE EVALUATION OF THE APPLICABILITY OF BRT SYSTEMS IN İZMIR

Bu çalışmada, otobüs ve hafif raylı sistemin kendine özgü avantajlarını bir arada barındıran hızlı otobüs sistemi, planlama ve uygulama açısından irdelenmiş; planlamada ve karar aşamasında karşılaşılabilecek problemler ortaya konulmaya çalışılmıştır. İzmir kenti örneği üzerinde, planlamanın ilk aşamasını oluşturabilecek basit bir mevcut sistem verimlilik analizi uygulanmış; kent merkezini körfezin güney şeridiyle birleştiren bir hızlı otobüs uygulamasının yararlı olabileceği sonucuna varılmıştır. In this study, bus rapid transit systems which include some specific advantages of urban bus and light rail transit systems are investigated for planning and application points of views and the problems which may be encountered in decision making process are evaluated. An elementary efficiency analysis for urban bus systems which may be reconstructed for a bus rapid system is suggested. The analysis of İzmir urban bus system shows that a bus rapid system connecting the central business district and south coast of the İzmir Bay can be an efficient transportation investmen

Passenger Flows Estimation of Light Rail Transit (LRT) System in Izmir, Turkey Using Multiple Regression and ANN Methods

Passenger flow estimation of transit systems is essential for new decisions about additional facilities and feeder lines. For increasing the efficiency of an existing transit line, stations which are insufficient for trip production and attraction should be examined first. Such investigation supports decisions for feeder line projects which may seem necessary or futile according to the findings. In this study, passenger flow of a light rail transit (LRT) system in Izmir, Turkey is estimated by using multiple regression and feed-forward back-propagation type of artificial neural networks (ANN). The number of alighting passengers at each station is estimated as a function of boarding passengers from other stations. It is found that ANN approach produced significantly better estimations specifically for the low passenger attractive stations. In addition, ANN is found to be more capable for the determination of trip-attractive parts of LRT lines.   Keywords: light rail transit, multiple regression, artificial neural networks, public transportatio

EVALUATION OF FRICTION RESISTANCE OFURBAN ROADS OF İZMİR IN TERMS OF TRAFFIC SAFETY

Modern bir karayolu, taşıtların güvenli, konforlu ve ekonomik bir şekilde seyretmelerine olanak sağlamalıdır. Günümüzde otomotiv endüstrisinde meydana gelen hızlı gelişmelerin taşıt hızlarının dolayısı ile trafik kazalarının artışına neden olduğu göz önüne alındığında, güvenlik ihtiyacı yukarıda belirtilen üç zorunluluk içinde öne çıkmaktadır. Karayolunda güvenli bir sürüşün sağlanabilmesi için de taşıt tekerlek bandajı ile yol yüzeyi arasında meydana gelen kayma direncinin belli bir seviyede olması gerekmektedir. Bu çalışmada İzmir şehir içi yollarında Dinamik Sürtünme Ölçer (DFT) cihazı ile kayma direnç ölçümleri yapılmış ve trafik kazaları ile ilişki kurulmaya çalışılmıştır. A modern highway must be capable of proving safety traffic, comfort to passenger cars as well as efficient and economical transportation. In view of the increase in the number of traffic accidents due to the devolopments in automative industry, the traffic safety has gathered much consideration among the other parameters in recent years. In order to provide traffic safety, the friction resistance between the vehicle tyre and surface should be in certain level. This study aims to evaluate the friction characteristics on the urban roads of Izmir by way of Dynamic Friction Tester as well as build a relationship between the traffic accidents and measured parameters

AN INVESTIGATION BASED ON PASSENGER AND FREIGHT DEMANDS VARIATION OF ADNAN MENDERES AIRPORT

İzmir, ülkenin en önemli sanayi ve ticaret merkezlerinden biri olmasının yanısıra son yıllarda artan turizm hacmiyle de oldukça önemli bir merkez haline gelmiştir. Özellikle 2003 yılından sonra sivil havacılığın teşvik edilmesi ve artan talepler doğrultusunda hızla gelişen havayolu taşımacılığında İzmir/Adnan Menderes Havaalanı önemli bir konumdadır. Sosyo–ekonomik kalkınma, bireylerin ulaşım alışkanlıklarının değişmesine neden olmuş ve havaalanları için yıllara bağlı olarak sosyo–ekonomik veriler doğrultusunda yolcu ve yük taşımacılığında nasıl bir değişim olacağı önem arz eden bir konu haline gelmiştir. Çalışma kapsamında, İzmir/Adnan Menderes Havaalanı yolcu ve yük sayısındaki değişimler, sosyo –ekonomik göstergeler ile incelenmiştir. Çalışmalar sonucunda yolcu ve yük değerlerinin özellikle Gayrisafi Yurtiçi Hasıla ile yakından ilişkili olduğu görülmüştür. İthalat ve ihracat verileri ile havayolu yük taşımacılığının, araç sayısı ile yolcu ve uçak sayısının ilişkili olduğu ve bu nedenle havalanına gelecekteki taleplerin hesaplanmasında kullanılabilecekleri anlaşılmıştır. Ayrıca, iç hatlardaki yüksek doluluk oranı dış hatlarda yakalanamamakta, İzmir'in uluslararası uçuş olanaklarının geliştirilmemesi durumunda dış hatlar terminalinin kapasitesinin çok altında hizmet vermeye devam edeceği belirlenmiştir. Izmir is one of the most important industrial and commercial center of Turkey. In recent years with the increasing volume of tourism the city has become a significant city of the country. After 2003, by the promotion of civil aviation and the increasing demands for air transportation Izmir has become one of the most important air transportation center. With the increasing in socio–economic standards, transportation habits of people have also changed. The changing in the passenger and freight transport for the future has become one of the most important issues for İzmir/Adnan Menderes Airport. In this study, the changes in passenger and freight values have investigated with socio–economic data. The results have shown that, passenger and freight values have a significant relation with Gross Domestic Product (GDP). There is a similar relation between the values of import, export and air freight transportation. The number of total vehicle and the number of passenger – freight have also significant relation. By this way, all these data have been able to use to determine the future demand of the airport