Analysis of the Possible Savings of Cycle Time on Tram Line No. 17 in Zagreb

Abstract

The cycle time on tram line T is theoretically defined as a sum of the total operating (travel) time on line T_o and the total time at terminals t_t. In order to ensure the increasing of the operating and cycle speeds of trams in Zagreb, as well as increasing the gross transport work of a single line with the same number of trams and drivers in one shift, this paper has explored a scenario for simulating cycle time savings by reducing the total operating time, both achieved by the possible implementation of tram priority via traffic lights based on the local automation. Possible realistic saving of the total operating time ΔT_o on line No. 17 in Zagreb is based on the assumption that all signals at the traffic lights for trams should be green due to tram priority via traffic lights. Real operating time savings ΔT_o was measured by using the stopwatch - pencil - record list method. The measurements were conducted in the middle shift during the afternoon peak load, as well as in the early shift during the morning peak load, for all of the seven days in one week, and for the new tram NT 2200 which accounts for 51% of the ZET tram fleet, on line No. 17. This paper has explored the ideal and maximum positive cycle time scenario, based on the measurement of possible maximum operating time savings ΔT_o as the sum of the duration of all red signals at traffic lights for trams in one cycle in real traffic situations in Zagreb.