Transportation

Various public transport concepts have been developed to provide solutions to the ever growing problem of traffic in modern times. For instance, intelligent subscription bus service is one of them. This concept aims to provide a means of transport at near private car comfort as well as at near public transport cost. By this means, a shift from other modes of transport, especially private car, to public transport is aimed to encourage use of public transport. An artificial neural network model has been developed in this study to be able to calculate modal shift using three sources of data obtained from two questionnaire surveys conducted at Akdeniz University campus and a computer model's output (based on shortest route algorithms). The relationship between the results of the second questionnaire survey and the other data have been entered into Weka and Rapid Miner programs, the accuracy of this machine learning has been calculated and finally the modal shift originated by the intelligent subscription bus services has been estimated. The findings have yielded very reliable results which revealed the potential of applying the technique easily to similar problems

Gelişmiş ülkelerde 50’li yıllarda eski tip dönel kavşakların yerine Modern Dönel Kavşak türü geliştirilmiştir. Bu değişimdeki en önemli faktör, kavşak geometrisinin araçların hızını azaltmak zorunda kalacakları şekilde tasarlanması ve “Ada Etrafında Dönen Araca Yol Ver” kuralının getirilmesidir. Bu kural ülkemizde işletilemediği gibi eski tip dönel kavşaklardan modern dönel kavşaklara sorunsuz bir geçişin sağlanması için yapılması gerekenler de literatürümüzde henüz yeterince işlenmemiştir. Bu çalışma ile bu dönüşümün başarıyla yapılabilmesi için gerekli olan geometrik modifikasyon, sürücü eğitim metotları ve sürücülerin dönüşüme adapte olabilmesi için kavşaklarda bulunması gereken trafik işaretlemelerinin bilimsel olarak belirlenmesi amacıyla kullanılabilecek yöntemler simülatör senaryoları halinde verilmiştir. Ayrıca elde edilecek deney sonuçlarının nasıl değerlendirilmesi gerektiği, standardın nasıl hazırlanabileceği ve yetkililerin bu yeni standardı nasıl benimseyip uygulayabileceği konusunda da yol gösterici bilgiler bu bildiri ile aktarılmaktadır.

ÖZET Akıllı Servis Araçları (kısaca A-Servis) konsepti, rezervasyon sistemi ile çalışan ve yolcularına geleneksel toplu taşımaya göre daha kısa sürede yolculuk imkânı veren esnek ve dinamik bir toplu taşıma hizmetidir. Bu çalışmada Akdeniz Üniversitesi kampüsüne düzenli olarak seyahat edenler için bir anket çalışması yapılarak katılımcıların bu hizmeti kullanma durumu modellenmiştir. A-Servis hizmetiyle kampüse olan yolculuk sürelerinin ne kadar süreceğinin tespiti amacıyla Antalya şehiriçi yol ağı haritası ve bu yol ağına ait zaman-yolculuk süresi veri tabanı oluşturulmuştur. Bu veri tabanını ve Dijkstra algoritmasını kullanarak güzergah hesaplayan yeni bir yazılım geliştirilmiştir. En kısa yolculuk süresi prensibine göre çalışan bu yazılım ile servis araçlarının kullanacağı optimum güzergahlar ve her bir katılımcı için yolculuk süreleri tespit edilmiştir. Ankete katılan kullanıcılara bu hizmet tanıtılıp, kendileri için belirlenen avantajlar bildirilerek önerilen A-Servis hizmetini tercih edip etmeyeceklerine dair ikinci bir anket çalışması yapılmıştır. Böylece farklı ulaşım türlerinden A-Servis sistemine olan türel değişim (modal shift) miktarı tespit edilmiştir. Anahtar kelimeler: Dijkstra algoritması, optimum güzergah, türel değişim (modal shift), yol ağı haritası. The concept Intelligent Service Vehicles (briefly A-Service) which works on the basis of a reservation system, aims to provide shorter travel times to its subscribers compared to standard public transport services, offers a dynamic and flexible public transport service. In this study, a questionnaire survey has been conducted among the commuters of Akdeniz University campus and their interest in the service has been modeled. In order to determine travel times to the campus by A-Service, Antalya urban road network map and real time vs. travel time database has been produced. A new software has been developed to calculate optimum routes using this database and Dijkstra algorithm. Optimum routes to be used by the service vehicles and the travel times for each participant are determined by this piece of software which works on the shortest travel time principle. The proposed hypothetical service was introduced to the participants, then the anticipated advantages for each participant are reported back to them by means of a second questionnaire survey to determine whether they would prefer A-Service or not. Thus the amount of modal shift was then determined from various other modes to A-Service.

High vehicular speeds are one of the most frequent complains in urban roads. Lack of obedience to speed limits results in many fatal accidents. Traffic calming measures have been widely used in many developed countries to reduce accidents, the negative effects of speeding and traffic noise in urban roads. In the scope of this study, horizontal calming measures, namely chicanes, which are not in use in Turkey yet, have been studied by using a driving simulator for the aim of controlling and reducing vehicular speeds. For this purpose, Akdeniz University campus was selected as the pilot case area and a number of different roads in the campus have been modeled in 3D. It was determined from the speed data that for divided four lane carriageways, chicane number 10 (K10) which has 3 m effective width and 45 deg. entry and exit angles, for undivided two lane carriageways, chicane number 2 (K2) which has 2.7 m effective width and 60 deg. entry and 30 deg. exit angles, gave the best outcome from the driving tests in accordance with the characteristics of Turkish drivers. Furthermore, based on the findings, common driver errors are identified and a number of recommendations are made.

A number of measuring scales have been developed for the purpose of determining the acceptability levels of travel routes from the geometry point of view for urban networks. These scales have been studied under four headings: Distance as the Crow Flies, Average Speed, Alternative Routes and Angular Deflection. Besides, in order to be able to evaluate all these scales simultaneously, a common scale has been introduced. This, therefore, will enable researchers and practitioners to compare the road networks of various cities with varying size and geometry. These scales are then applied on a number of different cities around the world, and the road networks belonging to these cities are ranked according to the rationality criteria introduced.

The concept of rationality, which uses the layouts of the routes connecting pairs of points on an urban road network as a quality indicator, has been a new research field in recent years. In this study, a new, Monte Carlo based, method is proposed for measuring the rationality of road networks. By improving the scales that were developed earlier by previous work, the applications of the route rationality scales on various types of road networks of various sizes
became possible. This was achieved by writing a piece of software which is capable of accessing Google Maps and retrieving huge amounts of location and route data for very fast computations. The technique used three algorithms, i.e. random point selection, the greatest triangles, and the homogeneous dispersion. Finally, an application of the method is tested in Ankara.