## 2 Materials and Methods  
The City of Zagreb is the capital city of the Republic of Croatia, consisting of 70 settlements with a total area of approximately 641 km\({}^{2}\). In total, 0.8 million residents live within the City's administrative limits, and 87% of these residents occupy the Zagreb settlement. Surveys regarding residents' travel behavior, performed from 2016 to 2018 [25], showed that 40% of all urban trips in Zagreb were made by PT (bus, tram, or train) and that the tram network was the PT's backbone, as 55% of trips were made by tram. The following is a brief description of the basic characteristics of Zagreb's tram system, elaborated upon in detail in [26], based on which the representative sample of 3 tram stops for dwell time investigations was selected. The tram network in the City of Zagreb (Figure 1) consists of a total of 58 km of double, 1.000 mm gauge track (excluding the tracks in two tram depots situated in the eastern and western parts of the city on the outskirts of the central business area). The network contains 18 tram turnarounds, 9 of which are PT terminals, and 240 single and 18 double tram stops. Tram transport was organized through a total of 19 tram lines: 15 daytime (from 4 a.m. to 12 a.m.) and 4 night-time (from 12 a.m. to 4 a.m.), with a total length of 216.5 km. On an annual basis, the transport was arranged through 2 seasonal daytime and night-time timetables (one 3-month period for the summer and a 9-month period for autumn, winter, and spring). In each period, the timetable was determined separately for working days, Saturdays, Sundays, and public holidays. The rolling stock consisted of 317 tram vehicles, of which 266 were motor coaches, and 51 were trailers. Most tram vehicles were low-floor tram motor coaches; a total of 140 have been in use since 2005. The average age of older types of high-floor trams (of 4 different types) is 35 years. During the rolling stock service life, on average, each vehicle has traveled 1.2 million km. Payment for PT services was made in vehicles through individual, daily, monthly, and annual tickets, which was the so-called mixed tariff system. Passengers can use 3 types of tickets for transport: prepaid cards, daily tickets, and multi-day tickets, as well as individual tickets. All vehicles were equipped with validators that allow the validation of electronic and paper tickets. Validators for the validation of electronic tickets were installed in every vehicle near every door. The validation of paper tickets was only possible using validators located near the first door of all vehicles and, additionally, at the rear doors in low-floor trams. The network's layout, tracks, and stop positions in streets' cross-sections was characterized by the network's historical development. A total of 50% of the tracks were located inside the street carriageway, adjacent to the sidewalks, which was typical for tram networks that began to develop during the era of Austria-Hungary. Sidewalks were used as platforms for 40% of the single stops. This track/stop platform layout predominates in the central city area and along the main streets of the city. Outside the center, along city avenues, tracks were laid in separate central corridors. Here, the stop platforms were constructed as elevated islands, usually located on the far side of larger street intersections. Figure 1: Double-track tram network in the City of Zagreb. Passengers gain access to these by a level crossing or an underpass at the far end of the platform. For safety and comfort, on 62% of island platforms, passengers were separated from the carriageway by a protective fence, and 67% of all stops were equipped with shelters. Around the network, the average inter-stop distance was 465 m. The layout characteristics of single-stop platforms (height, width, and length) are presented in Table 1.  
As can be seen from the average line speed indicators during the autumn, winter, and spring months given in Table 2, the average line transportation speed and turnaround cycle speed were quite low.