Akademik Veri Yönetim Sistemi
Transportation Research Record, 2025 (SCI-Expanded)
Highway interchanges should not be left “unattended” when it comes to signage, but in many countries such key locations lack adequate speed limit signs. Therefore, drivers, who normally expect “accustomed” lateral acceleration levels when negotiating the loops of interchanges, have to choose correct speeds on their own. The paper reveals the extent of this problem using ball-bank data collected from four Turkish cloverleaf interchanges. Three criteria are introduced: 1) first maximum, 2) rate of change of radial acceleration, and 3) average riding comfort along the loops. The following features are scrutinized: in criterion 1, the first maximum ball-bank reading for each loop against its corresponding speed; in criterion 2, how quickly the lateral acceleration develops as the test vehicle enters and exits a loop; and in criterion 3, the average values of ball-bank readings as the test vehicle travels along the loops. To maintain the same level of lateral comfort, the test vehicle had to experience about 6 km/h speed variation among the loops of the same interchange, and more than 15 km/h speed variation among the interchanges studied, as far as criterion 1 is concerned. In relation to criterion 2, the test vehicle underwent a faster ball-bank differential when entering a loop than it did when exiting. With regard to criterion 3, about 4 km/h speed variation among the loops of the same interchange and nearly 16 km/h speed variation among the interchanges studied were recorded. The methodology developed in this paper can easily be adapted for similar objectives to study the loops of interchanges in other countries.