The Transit Network Design and Frequency Setting Problem (TNDFSP) can be defined as the creation of effective routes in a public transport network and the determination of relevant frequencies. Generally, the TNDFSP problem is in the same category as the Traveling Salesman Problem (TSP), which is known to be a non-deterministic polynomial-period (NP-hard) difficult problem. This study consists of two stages: first, the design of a public transport network with an evolutionary optimization technique – the Intelligent Water Drops (IWD) algorithm – based on the TSP and the determination of relevant frequencies; and second, the assignment of passengers to designated routes. All decisions related to public transport network design may be evaluated by considering environmental costs in relation to passengers, operators and the environment. This study presents an acceptable, constructive and original algorithm.

Policy makers and planners evaluate the implementation of the urban public transport (UPT) planning studies in terms of some objective measures such as load factor, mean volume per trip, capacity usage ratio and total capacity. In some cases, improving these measures may lead an unforeseen decrease on accessibility to the opportunities in terms of UPT users. Thus, this study aims to evaluate Potential Accessibility (PA) as an efficiency measure in decision stage of UPT planning. It widely depends on fieldwork, surveys, data inventories and existing plans. In this context, a comprehensive UPT planning has been carried out through VISUM traffic simulation software by taking the PA into account, and a four-step UPT planning procedure has been proposed. The results showed that PA may alternatively be used as an evaluation instrument in decision stage of UPT planning while the objective measures are insufficient to represent the effectiveness of alternative scenarios.

Journal of Traffic and Logistics Engineering (JTLE)

Transit planning scenarios may lead to the different Objective Function (OF) values since each scenario has different transit travel times, frequencies and fleet sizes. Change on those variables leads to the different accessibility values for each route set. Therefore, the actual performance of a route set may be unforeseen since the accessibility values are out of evaluation criteria. This study tries to generate techniques, which handle the relation between accessibility and transportation in the scope of public transit. The accessibility measures, which have direct relation with land use and transportation, are utilized in transit route set decision. Accessibility measures have been utilized in the decision-making process of transit network design. Conventional OFs, which are used to determine the most effective route sets are combined with accessibility based OFs and the decision-making process of transit network design is strengthened. In this context, the effects of accessibility measures in decision-making process of transit network design have been represented on an 8-node example transit network. The results showed the accessibility measures could effectively improve the planners’ decision accuracy.

Ülkemizde ulaşım alt türler arasındaki dengesizlik ve entegrasyon en önemli problem olarak karşımıza çıkmaktadır. Çalışmada son yıllarda içhat hava taşımacılığı alt türünde gözlenen talebin aylık değişimini yansıtabilen indeksleme yöntemi kullanılarak modellemesi yapılmış, geleceğe yönelik tahminler yapılarak alt türlerdeki dengesizliğin giderilmesi yönünde önerilerde bulunulmuştur. Modelleme çalışmasında bağımsız değişkenler olarak Satın alma Gücü Paritesi ve jet yakıt fiyatları kullanılmıştır. Kullanılan yöntem ile aylık ve mevsimsel değişmelere duyarlı bir model geliştirilmiştir. Yapılan hesaplamalar sonucunda gelir seviyesinde iyimser gelişmeler gözlenmesi ve jet yakıt fiyatlarında düşük seyrin gözlenmesi durumunda karayolu ulaşım sisteminin ardından hava taşımacılığının demiryolu sistemi ile ciddi bir rekabet içinde olacağı belirlenmiştir. Bu nedenle ücret politikalarında gerekirse jet yakıt fiyatlarında vergi düzenlemesi ile talep gelişiminin desteklenmesinin gerekli olduğu düşünülmektedir