FORECASTING THE LOAD ON NIGHT BUS LINES: A CASE STUDY OF THE MUNICIPAL TRANSPORT COMPANY IN PIlA

The main purpose of this article is to make a forecast of the load on the night lines using the Municipal Transport Company in Piła (MTC) as a case study. This article characterizes the concept of urban logistics and mobility, and then proposed a mobility model that considers the preferences of residents when choosing a means of transport. Finally, it ends with a survey and the appropriate conclusions drawn.


INTRODUCTION
The essence of logistics is the flow of material goods and information as well as their intensity, continuity and reliability [1]. The spatial concentration of industry, trade and services in a small area always creates smaller or larger problems with their functioning. These are mainly difficult transfer, storage and punctual delivery processes. That is why in the 1980s and 1990s, the concept of urban logistics was used for the first time. From English, "city logistics" is a tool for solving problems related to traffic pathology in highly urbanized areas [2].

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In the analyzed city, which is Piła, communication at night operates during one night of the year when the Museum Night takes place. It is a route specially prepared for residents giving the opportunity to get to the two museums of the city. There are two lines: A and B. The frequency of the courses is once per hour.
The proper functioning of the city depends on many elements. Each of them is relevant and dependent on each other. When one stops working, the rest have a difficult job. Over the years, each area has developed its own urban logistics. Well designed, it prevents city congestion, creates liquidity and no delays, and at the same time, due to increasingly new technological solutions, it has become more ecological.

CHARACTERISTICS OF THE CITY OF PIŁA AND THE MUNICIPAL TRANSPORT COMPANY IN PIŁA
Piła is a city located in northwest Poland in the Greater Poland Voivodeship. Currently, it has about 70,000 inhabitants, and its area is 102.68 km². According to data from 2017, the most populated areas are Górne (about 13,000), Zamość (about 19,500), and Śródmieście (about 14,000). The smallest number of inhabitants is Gładyszewo (around 500) with Motylew (around 900). Moderate population occurs in the following districts: Jadwiżyn (about 5,000), Koszyce (about 5,000), Podlasie (about 6,000) and Staszyce (about 6,000) [18].
The history of Piła urban transport dates back to the 1920s when the first 3 lines operated. During World War II, the city was so damaged that it was not reopened until July 1, 1957. By the decision of the Provincial National Council in Poznań, the Municipal Transport Plant was established at the Municipal Enterprise of Economy in Piła. Initially, it was located at 10 Kujawska Street. Presently, it is located at 4 Łączna Street [19].
On December 29, 2000, the Miejski Zakład Komunikacji Limited Liability Company in Piła was officially formed following the transformation. Then, apart from the old rolling stock, the company already had 2 new Neoplan N4009 buses and 8 Neoplan N4016 buses.
There are currently 24 bus lines in Piła. Below is a diagram of communication lines. At designated times and seasons based on several years of research, they are shortened or extended. The current scheme of public transport lines is shown in Figure 1.
On January 30, 2021, MTC rolling stock in Piła had 47 buses. There are three main brands that MTC purchases the most. They are Solaris, Neoplan and Mercedes. The number of all buses 53 The share of buses adapted for the disabled in the fleet 93% The average age of the operated bus fleet 11 years

GENERALIZED MOBILITY MODEL
Considering the objectives of transport activities and the preferences of residents, we can assume that we can define the mobility model of city users using the following elements [20]: • user bases -BU, • mobility structures -SM, Forecasting the load on night bus lines: a case study of… 79.
• choice of means of transport -ST, • a database of characteristics of BM mobility structure elements, • travel organization -OP, • residents' preferences -PM.
Given the above elements of mobility, the mobility model -MM can be presented in the form of the equation: In the above model, the set of users takes the form: where: Uis the number of users of the studied mobility.
Where: GWdetermines the number of all surveyed age groups, in this case, equal to 6.
The next element considered is the user base, which takes the form of the following vector: The structure of mobility of residents in the mobility model of city users has been presented in the form of: where: PMis the mobility point PTcollection of transport connections.
The places of activity of city users (for example, place of residence, workplace or school) were taken as the mobility points, that is, the starting and ending point of travel. These also include intermediate points (for example, stations, stops, parking lots, etc.) known as intermediate points. Each component included in the residents' mobility structure contains characteristics specific to transport activities such as, for example, waiting time at the stop, parking cost, etc.
Another of the discussed mobility component is the choice of the means of transport, which we can present in the form of: where: cptravel time, kpthe cost of travel, kdtravel comfort (in this case, the traveler can count on, among others, rest, eating a meal, comfortable seating), bsttravel safety, dstavailability of means of transport (we can include here extensive point infrastructure, for example, bus and railway stations, passenger terminal, number of connections per day), wbluggage size, pstpunctuality of the means of transport, zisource of information on the timetable, cktravel frequency, sysynchronization with other means of transport, ośenvironmental protection.
The last of the considered mobility elements is the base of characteristics of elements of the mobility structure defined in the form: where: ZCPMreferred to as the set of characteristics described at mobility points, ZCPTreferred to as the set of characteristics described on transport connections.
The next of the discussed elements is the organization of the travels of the OP. The model assumes two variants of travel organization: (10) where: OP=1means a one-step variant, OP=2means a three-stage variant.
A one-stage journey is very rare, only if someone travels on foot. We can describe it in the form of: where: ppis the starting point of the trip, pkis the end point of the journey.
Usually, the three-stage journey consists of the following elements: walking, for example, reaching the stop, public transport, and walking to the destination. We can describe this kind of travel in the form of a vector: where: n1, n2waypoint number.
Considering the mobility model of residents together with their preferences, presented in formula (1), research on the preferences of residents was started.

Purpose and scope of research
The purpose of the survey was to find out the opinions of residents and people commuting to Piła on the introduction of night lines in the city of Piła. The survey was addressed mainly to students because they are young people with a completely different view of the environment than the older people. This study was to answer the question whether the introduction of night lines is justified. The questions were short and did not require complicated answers. The survey has been arranged so that as many people as possible complete it with the least amount of time.

Research methodology
The research was conducted in the form of surveys. In the beginning, a pilot study was carried out, based on which the question sheet was corrected. Then the survey was carried out at the following entities:  Signify Piła,  Complex of Economic Schools in Piła,  School Complex at Teatralna in Piła, to learn the opinions of people using public transport.
The survey consisted of 14 closed questions that asked, among others, about sex, age, place of residence. The questions also concerned the desire to use the night line, the price of the night ticket and the housing estates where the night line should be introduced. At the end of the study, each of the respondents had the opportunity to propose MTC development directions. In total, 320 people were surveyed.

Research object
Based on the research, it was observed that in the group of 320 people, 48% were men and 52% were women. The most numerous group were young people between 16 and 19 years old. They constituted as much as 72%. This is due to the places where the surveys were carried out, that is, two high schools. People over the age of 20 constitute only 28% of the respondentsthey were employees of Signify. The results are presented in Figure 2.

Fig. 2. Age range of respondents
Another question concerned the place of residence. The percentage share of people living in the city of Piła was dominant. It accounts for up to 59%. The second largest group are people who marked "Other" -17%. They were people living in, among others, Osiek, Nakło nad Notecią, Kaczory, Białośliwie, Wysoka, and Radawnica. The small groups are other people residing other than those listed above. The results are presented in Figure 3. Another question concerned the frequency of using public transport. As much as 25% of respondents marked the answer "several times a year", 24% "daily", 22% "several times a week", 16% "several times a month" and 13% "not at all". Surveys of people who answered this question "not at all" were not considered in further studies. In this question, the answers are evenly distributed. The results are presented in Figure 4.

Fig. 4. Frequency of using MTC Piła
The next question concerned the hours of using MTC. Usually, respondents use public transport between 14:00 -18:00. This answer was given by 36% of the respondents. The answer with hours of use 4:00 -8:00 is 22%. Hours of use between 4:00 -13:00 and 19:00 -23:00 were marked by the same number of respondents -they constitute 21% each. The results are presented in Figure 5. The leading answer to the question about the destination is "travel to/from school" and "family/friends". Both answers were given by 31% of respondents. While 19% answered "shopping", 10% "commuting to / from work" and 7% "health". Answers in the "Other" category (2%) are extracurricular activities. The results are presented in Figure 6. People choosing the MTC chose time (33%), price (24%) and convenience (23%) as the main choice factor. The least people considered punctuality (8%) and environmental protection (5%). The "Other" factor accounts for 7% of the answer -this is due to the lack of a driving license. The results are presented in Figure 7. The level of satisfaction with the services provided by MTC is high -16% of the respondents answered "satisfied" and as many as 70% rather satisfied. This works for the company. Only 14% of the participants indicated a negative answer about the degree of satisfaction with the transport company. The results are presented in Figure 8. To the next question about the desire to use night lines upon their introduction, more than half of the respondents (57%) answered in the affirmative, while 43% answered in the negative. This means that most of the respondents are for the development of the company and the use of night lines. If any of the respondents gave a negative answer to this question, their survey was not considered in further studies. The results are presented in Figure 9. When asked whether despite the introduction of a higher rate for a ticket, the respondent would still be interested in using it, 80% of respondents said yes. The results are presented in Figure 10.  In this case, the Śródmieście district also enjoys the greatest interest among potential passengers (23%). People participating in the study were also largely interested in the arrival of night lines to such districts as Górne (14%), Zielona Dolina (11%) and Podlasie (11%). Other districts received less than 10% of the respondents' answers. The results are presented in Figure 12.
Forecasting the load on night bus lines: a case study of… 87. The next question concerned the days of using public transport. People interested in using the night lines strongly indicated the answer "Friday-Saturday" (32%) and "Saturday-Sunday" (29%). This is the most frequently chosen time of the week when respondents can meet with friends and spend some time with them. Hence, the night life flourishes in the city. The results are presented in Figure 13.

THE CONCEPT OF INTRODUCING NIGHT LINES IN PIŁA
Based on the research conducted, the district that enjoys the greatest interest in departures and arrivals of night buses is the Śródmieście / Centrum district, that is, the place where Piła's nightlife mainly takes place. The next most frequently chosen districts are Zielona Dolina, Podlasie, Zamość and Górne. Due to the possibility of conducting tests in three different places, the following night lines were developed: N1 and N2. The N1 line would consist of 16 stops and connect the Zielona Dolina housing estate with the Górne housing estate. The N2 line would have 21 stops and would connect the Podlasie housing estate with the Górne housing estate.
When creating routes, districts such as Koszyce / Zalew Koszycki, Motylewo, Gładyszewo and Staszyce were excluded due to the low interest of the respondents. Night lines would intersect at Aleja Piastów/Hotel Gromada because it is the very center of the city. The map below presents 2 routes of night lines. Green is the N1 line while yellow is the N2 route ( Figure 14).
The timetable and driving time were created based on this research. It was assumed that buses of Piła MTC run at an average speed of 40 km/h and the route of lines N1 and N2 was carried by a passenger vehicle. The travel time of the N1 line from point A to point B is 19 minutes. The travel time of the N2 line from point A to point B is 24 minutes. Loop buses would run every 30 minutes. The courses are organized so that there is one bus and one driver per night line. Based on the research, it was proposed that the night lines should initially be introduced from Friday to Saturday and from Saturday to Sunday and run from 23:00 to 4:00 at night. Based on the calculations used, the buses on the two night routes N1 and N2 cover a total of 24 routes from point A to point B and back, which gives 216 kilometers in one night. The projected cost of both lines in one weekend is PLN 3244.32. Assuming that on average there are four weekends a month, the forecast monthly costs are PLN 12,977.30. For the Municipal Transport Company in Piła to gain from night lines, a uniform rate of PLN 4 should be introduced. This means that 850 passengers should use it during the weekend. If the MTC had introduced a uniform ticket rate of 4.5 PLN, 750 people should use it during the weekend, and 680 passengers at 5 PLN, respectively, taking into account the cost of 1 car kilometer in 2021.

SUMMARY
To create effective urban logistics, that is, one that facilitates movement and does not cause transport difficulties, takes an adequate amount of time, people and financial outlays. Each element must cooperate with each other from the correct condition of roads, to people serving companies and transport to the right number of apartments. There are many links here, which at first glance seem insignificant.
Analyzing the activities of the Municipal Transport Company in Piła, one can observe its large development. The company invests in new vehicles every year, which ensures cleaner air. MTC started with several bus lines and currently has about 20 of them. A great opportunity for even faster development will be the introduction of electric vehicles in future years, for which the company has received large funding.
The idea that was proposed for the development of the city was the introduction of night lines. This will make the city more attractive, and maybe re-develop the nightlife that has recently disappeared.