Autonomous vehicles (AVs) are increasingly recognized for their potential to enhance urban traffic systems, particularly in traffic management and sustainability. This study explores AV integration into urban networks, focusing on transitions of control (ToC) and dedicated lane (DL) applications at varying AV penetration rates. Through simulations, various scenarios reveal the complex interactions between AVs and human-driven vehicles in mixed traffic conditions. The findings show that DLs can reduce local density, occupancy, and time loss by 5–35%, while improving travel time reliability by 15–25%. On an urban scale, DLs generally enhance traffic flow and reduce emissions, though the effects of ToC vary based on traffic conditions and AV automation levels. At lower AV penetration rates, ToC can lead to increased travel times and up to a 10% decline in traffic performance due to unpredictable human driver behavior during control transitions. The results highlight that DLs can significantly improve traffic flow, travel time reliability, and emissions, thereby contributing to sustainable urban mobility. However, the impacts of ToC are more complex, depending on specific traffic conditions and AV automation levels. This study emphasizes the importance of well-designed ToC and DL applications to optimize AV integration and support a balanced, sustainable future for urban mobility.

Although many traffic circles have been designed in Turkey, in recent years few studies have been made on the capacity and performance of roundabouts. In practice, two major problems at intersections need to be solved: traffic accidents and limited intersection capacity. With this in mind, the applicability of various capacity models for single-lane roundabouts to six selected roundabouts in Izmir, Turkey, is discussed. The results show that the HCM2000 procedure can be used as an effective tool for an initial prediction of single-lane roundabout capacity if the lower and upper boundary limits are calibrated. But, since the research was conducted with limited data, the accuracy of the results should be tested with more data sets. Further studies should be conducted to develop a more reliable capacity and performance analysis procedure, especially for Turkey.

Induced travel demand is a critical phenomenon for developing countries because neither road network nor the vehicle ownership have reached their contended phases. This leads to the opinion that induced demand is valid for developing countries or increase in travel demand is only a result of rapidly rising vehicle numbers and other socioeconomic parameters. In this study, induced demand estimation methodology is modified from the point of view of a developing country by introducing the application of tendency comparison of lane mile elasticities under different lag terms for control and highway investment data. Beside vehicle miles traveled, travel per vehicle (TPV) and number of vehicles for long-term effects are tried as new demand indicators. The selection of socioeconomic variables is also considered more expediently because of their rapid and wide changes in developing countries. The travel data of Turkish state highways are used for application. TPV is found to be the most distinguishable criterion of induced travel demand for Turkey with 2.0 times relative increase for private TPV and 3.5 times for commercial TPV. Demand elasticities based on commercial travel are found to be more permanent than the private travel based ones. Besides, longer peak period, which indicates the maximum difference in elasticity of control and test data, is obtained as $5\text{years}$ for commercial travel which is $3\text{years}$ for private purposed travel in lag consideration based on road supply conditions.

Although traffic circles have been widely used in Turkey for many years, only a few researchers are aware of the advantages of roundabouts. In recent years, few traffic circles were designed as roundabouts in Turkey, but limited study has been made on the capacity and performance analysis of roundabouts. In this study, the applicability of the Highway Capacity Manual 2000 (HCM 2000) procedure for roundabouts in Turkey is discussed. The results show that the HCM 2000 procedure can be an important tool for an initial prediction but further studies should be made in order to develop a more reliable capacity and performance analysis procedure for Turkey.

Toplu ulaşımda bekleme süresi, yolcuların algıladığı hizmet seviyesinin en önemli boyutlarından biridir. Özellikle trafik koşullarının etkisi altında işletilen kent içi otobüs taşımacılığında aşırı bekleme süresi, yolcuların tür ve güzergâh seçimini değiştirebilecek bir fayda fonksiyonu bileşenine dönüşebilmektedir. Bu çalışmada, kent içi otobüs taşımacılığında karşılaşılan bekleme süresi, hat ve durağa ait fiziksel koşulların yanı sıra, güvenilirlik ve yolcu bilgilendirme sistemlerinin etkisi de dikkate alınarak modellenmiştir. Oluşturulan doğrusal modeller sonucunda bilgilendirme sistemi varlığının bekleme süresini ortalama 2 dakika, güvenilirliğin ise ortalama 1,3 dakika kısaltıcı etkisi olduğu görülmüştür. Ayrıca yolcu bilgilendirme sistemlerinin, kent merkezinden gelen hatlar tarafından kullanılan ve geometrisine uygun kullanılan duraklarda uygulanmasının daha verimli olacağı sonucuna varılmıştır.