## 1 Introduction
### Objectives of the Paper  
Taking into consideration the above conclusion, we propose the following research question: how can we support decision making for increasing the performance of public transport in an attempt to increase the attractiveness of public transport? We selected Bucharest as the case study for answering the research question because recent studies [45] have shown that, in this city, the largest urban agglomeration in Romania, emissions from road traffic (PM10 and PM2.5) have become a major threat to air quality. In addition, traffic congestion has led to negative impacts on the economy, increased travel times and fuel consumption, a decrease in the reliability of cars due to frequent acceleration and braking, and a lack of accessibility for emergency vehicles (ambulances, fire engines, and police vehicles) [46]. Under these circumstances, more sustainable transport measures, such as public transport, must be considered by citizens. Bucharest has 770 km of bus network, organized into 104 lines; 282 km of tram network, organized into 24 lines; and 142 km of trolleybus network, organized into 17 lines, with a density of about 3.99 km/km2. For each public transport mode, there are 2288 stops/stations, as follows: 605 tram stations, 1385 bus stops, 57 trolleybus stops, and 241 common bus and trolleybus stops. The average distance between tram stations is 0.466 m; it is 0.497 m for bus stops and 0.483 for trolleybus stops. The average daily operating fleet is 1501 vehicles (266 trans, 1071 buses, and 165 trolleybuses). The number of passengers per day is 1.95 million, with a modal split of 47.08% for trans, 47.18% for buses, and 9.74% for trolleybuses [47]. To maximize the ease of use and efficiency of the public transport system in Bucharest, the fare systems have recently been integrated [48]. However, the public transport lacks timetable integration. In addition, even though investments have been made for the partial replacement of the public transport fleet of vehicles in recent years, Bucharest's surface public transport still lacks attractiveness. To respond to the research question, the first step was working, with open tools, on a digital map of public transport, which is not currently available for the surface public transport in Bucharest (or in other Romanian cities), despite the fast digitization process initiated by the public administration due to the COVID 19 pandemic [49]. The second step was to explore the analysis of public transport performance supported by the elements related to (i) the accessibility of public transport and (ii) optimizing the headway of vehicles. According to the service contract, the public transport operator in Bucharest evaluates public transport performance based on \(11\) indicators [50]: (1) the trips that are canceled or irregular due to operator fault; (2) routes canceled for a period of 24 h due to operator fault; (3) the number of passengers affected by the trips or routes canceled due to operator fault; (4) the total number of vehicles used daily, compared to the number of vehicles necessary for the realization of the schedule (weight: 5.0%); (5) complaints regarding the quality of transport; (6) environmental protection; (7) vehicles (the average age of the vehicles in the operating fleet and comfort requirements); (8) the compensation paid by transport operators for non-compliance with quality and environmental conditions regarding transport; (9) the number of violations found and sanctioned by authorized personnel regarding non-compliance with legal provisions; (10) the number of traffic accidents due to operator staff; (11) an index of passenger satisfaction. The main weight was given to trip indicator (1), which is related to schedule adherence (39%); however, no clear details are provided on the specific methodology used for assessing public transport performance.