The problem of determining traffic and pedestrians delay in the city road-street network unregulated intersection area

The motorization level increase in the city of Kyiv, taking place since the late 1990s up to 2008, caused the increase of the traffic flow s intensity in the city and overwork of the city road street network (RSN). The city streets and roads intersections became the places of traffic and pedestrian flows network concentration. In the City of Kyiv over a half of all intersections of streets and roads are unregulated. Therefore, in the aforementioned conditions (continued motorization level increase, limited number of parking spaces, public transport lanes allocation), as well as increasing demand for individual vehicles (Segway, gyro scooters, bicycles), the problem of unregulated crossings operation assessment is relevant. Proper traffic organization, taking into account all traffic participants, is the factor of the whole system efficient operation. While analyzing the regulatory framework of Ukraine for the design and operation of urban transport infrastructure, there are several problem areas: the lack of sufficient description of the re quirements for the unregulated crossings design; the absence of a comprehensive assessment of the intersection including all traffic participants (ca rs, pedestrians, cyclists and public transportation); the absence of regulatory transportation capacity. The article proposes to introduce the common structure of indicators of unregulated intersection work efficiency of traffic network. Such indicators have been used for more than 50 years by American, European and other countries’ designers to solve urgent urban construction and transport problems. This direction uses the level of service (LOS) Concept that aims to maximize the comfort of the transportation infrastructure elements – roadway, sidewalk, pedestrian crossing etc. The main indicators in this concept are the traffic and pedestrians delay control in the unregu lated intersection area; this article deals with th e method of its determination. Thus the method of full-scale traffic and pedestrians delay measurements is provided. Multimodal intersection level of service (MMLOS) is determined using the automotive and pedestrian components.

The unregulated intersection of the city streets and roads is any RSN crossing or adjacent, which does not have traffic lights.
The simple intersection of city streets and roads is referred to as RSN crossing or adjacent, which do not have straight structures and elements (islets, road marking, etc.) that organize traffic.

PROBLEM FORMULATION
The purpose of this study is to develop and reason the methodology for evaluating the operation of unregulated intersection on the city's road-street network.
It requires the research and development of a scientific base for complex solutions of unregulated crossings when choosing them depending on the urban conditions. For this purpose it is necessary to collect and structure the road network output data -traffic intensity, flow composition, intersection geometry etc. The main objective of the study is to establish the boundaries of the effective functioning of unregulated crossings, depending on the urban planning conditions using the specified evaluation criteria -traffic delays, queuing length and lines capacity levels.

STUDIES AND PUBLICATIONS ANALYSIS
The theme of increasing the unregulated crossings efficiency in the city has been traced back to the 1960s. In Western Europe, the USA and the former USSR, crosssectional studies have been conducted, based on which two approaches can be outlined: -an approach based on Probability Theory, whose founder is E.M. Lobanov [1,2]. Also in this direction worked such scholars as Buga P.G., Shelkov Yu. D. [3], Romanov A.G. [4], (USSR); B. Grinschilds [5], T. Metson [6], (USA); as well as contemporary scholars Chikalin Y.M. [7,8] -an approach based on queuing theory with the introduction of a level of service (LOS) criterion. This trend has developed primarily in the USA and the Western Europe. The scholars D. Drew [13], I.E. Baervald, A.V. Trofimov [14], A.Y. Mikhailov [15,16] Prior to choosing the basic unregulated intersection model, it is necessary to classify the object of study according to the set of criteria characterizing the intersection operation conditions. The RSN unregulated crossings operation conditions in Kyiv can be divided into planning and transport ones, which in turn are divided into the following subtypes: Planning conditions include the city functional-planning area and the intersection geometry.
Transport conditions -the category of intersecting streets; transport flows priority; transport flow composition.
Based on the current State Building Standards [18,19] there are no clear criteria for the unregulated intersections operation in the city [32]. In the previous DBN B.2.3-5:2001 edition [18] the following transport conditions restrictions (the traffic and pedestrians intensity) were specified in the area of unregulated intersection as 700 units per hour of total transport flow and 150 persons per hour for one pedestrian crossing in the intersection zone. There was also a restriction on the category of streets -an unregulated traffic and pedestrian traffic scheme was allowed on city streets and local roads (residential streets). There were no planning restrictions regarding the intersection geometry. There is no regulation on the use of unregulated crossings at the level of the City Master Plan [20,33].
The intersection was designed in accordance with the city roads and streets design rules. In contemporary urban conditions, the ПІДВОДНІ ТЕХНОЛОГІЇ • 2020 Вип.10, 84-95 промислова та цивільна інженерія traffic intensity and its individual types (bicycle, gyro, Segway) increase, pedestrian mobility augment and growing demand for such services of the current standards are not sufficient for a comprehensive urban development assessment of the unregulated crossroads design solution.
Several parameters have been used to evaluate the work of the city RSN unregulated intersection. These parameters are described the US Highway Capacity Manual [21,22] and its German analogue [23]. These include delay level d, delay of pedestrians dp, 95 th grade queue length Q95, emissions level M, intersection safety G, and road transport costs D. For an unregulated intersection, the main efficiency indicator is traffic delay and pedestrians delay at the junction. These two parameters determine the Level of Service (LOS). The LOS Concept is used from Queuing Theory [14]. In the number of publications the LOS Indicator is defined as "quality characteristics that reflect such aggregate factors as speed, travel time, free makeover, driving safety and convenience" [14,15].

METHODS OF DETERMINING TRANSPORT TRAFFIC DELAY: THEORY AND PRACTICE
The methodology for determining the traffic delay according to HCM-2010 [22] is a 13-step algorithm. The HCM use boundary conditions for the unregulated intersections are the absence of influence of closely spaced crossings, except for those unregulated intersections that are located 0,467 km (0,25 miles) from the regulated intersection. Hereford, all movement directions in the unregulated intersection area can be divided into the ranks in relation to the right turn traffic (for X-shaped crossings) ( Step 3. Determine conflicting flow rates.
Step 4. Determine critical movement intervals and casual intervals Step 5. Potential capacity calculation. 5а) Potential capacity accounting neighboring regulated crossings. 5b) Potential capacity under road traffic lights.
Step 10. Determine common lane (right turn and turns).
Step 11. Determine movement directions delay.
For the model verification let us use the calculation of indicators at the intersection of Vishniakivska street and L. Rudenko street in Darnytskyi district (Kyiv) (Fig.3, 4). Open air examinations were conducted on June 25, 2019 (6:15-6:40 pm).
Initial data were collected in terms of traffic and pedestrian traffic intensity by the method [24] developed by the KNUCA MB Department. According to this method, the values of the traffic intensity are reduced to the average daily using the coefficients of non-uniformity [25]. Some parameters of the traffic flow, such as composition and time intensity, can be determined by [10, 26 -27]. The transition from daily average to hourly intensity can be made by the formula: . 0,08 where Nhrs -hour traffic intensity, veh/h; Nday -average daily traffic intensity, veh/day. The theoretical calculation of intersection operation according to [22] is performed in MS Excel. The whole algorithm of the problem is not specified in detail, but in Tables 2  and 3 were given the results of calculating delays of all movements d, s/veh. Under traffic delays we understand a traffic speed decrease compare to normative one, permitted by the Traffic Rules of Ukraine [28].
Analysis of field surveys is carried out according to the method described in [29]. In order to show the traffic situation, a 15 min video recording (five 3-min videos) was made (Fig.5). The manual data processing protocol is presented in Table 4.
The whole video is split into 1 min segments. The periods of detailed fixation of the vehicle number make 15 seconds. Each 15second segment shows the number of cars waiting in a queue nі.ч and every 1 min video shows the number of cars that stopped nзуп., or drove nonstop nб.зуп.
The processing of the delay determination results includes the following steps: The HCM-2010 traffic delay [22] where Σnзуп. -the total number of cars that stopped at the intersection during the observation period 3. Nominal delay of each car passing through the intersection is given by the formula: where nб.зуп -the total number of cars passing non-stop through the intersection. Calculate the appropriate parameters for direction 4: 1. We do the same calculations for directions 7 (3-2) and 9 (3-1). The results of theoretical and practical calculations are summarized in Table 5 to compare.  [3,4] Practical calculation according to [14] Error, % 4 (1-3) 9, 13 14,3 +36,0 7  135,99 24,6 -81,9 9 (3-1) 14,89 15 +0,73 As we can see, in two cases the results of theoretical calculations and experimental data differ significantly (over 10% error). There are several factors that can affect this: -Data collection accuracy; -Data analysis accuracy; -Data collection quality; -The need for calculation methods adjustment.

METHODS OF DETERMINING PEDESTRIANS CROSSING DELAY ON UNREGULANED INTERSECTION: THEORY AND PRACTICE
The pedestrian crossing delay method according to HCM-2010 is a 6-step algorithm that allows us to determine the level of service on an unregulated pedestrian crossing.
Step 3. Probability of delayed pedestrian crossings.
Step 4. Calculate average waiting interval delay.
Step 5. Estimate delay reduction due to yielding vehicles.
Step 6. Calculate average pedestrian delay and determine LOS (pLOS).
The pLOS Assessment Model, which was first tested in HCM 5th edition [22], offers three versions of unregulated pedestrian crossing: А. Unmarked crosswalk, no median safety islet; B. Unmarked crosswalk, median safety islet; C. Marked crosswalk with visible equipment and median safety islet.
HCM recommends the following data to determine pLOS: -Number of lanes on a major street; -Traffic intensity on a major street, veh/h; -Crosswalk length without median islet (option А), m; -Crosswalk length with median islet (option B and C), m; -Pedestrian crossing speed, m/s; -No pedestrian "jam traffic".
As an example, let us take the calculation of indicators at the intersection of Vishniakivska street and L. Rudenko street (see Fig.4), Tables 6 -8. On-site examinations were conducted on June 25, 2019, 6:15-6:40 pm. In general, within the framework of urban transportation planning, the general tasks of pedestrian crossing design are to calculate their capacity and to select the location in the street.
In the former USSR, pedestrian crossing subject was studied by such scholars as Buga P.G, Shelkov Y.D., Lobanov E.M., Romanov A.G., as well as contemporary Russian researchers Chikalin E.M., Simul M.G. etc. In 1977, an act was adopted [30] that addressed issues related to improving the pedestrian crossing arrangement. The one lane pedestrian crossing capacity is determined by the formula: 1,5 . 3600 .1 3600 where M -major street total traffic intensity, veh/h; λ=M/3600 -М traffic intensity mathematical expectancy, veh/s; Δtгр -critical interval in major street, s; δt -traffic interval in subordinate street, s The crosswalk capacity is determined by the formula: where bп -crosswalk width, m; bп.1 -crosswalk lane width, m (0,75 -1,0 m); Kр -adjustment factor of traffic road lights. Scholars Bug PG, Shelkov Y.D. offered a formula for estimating traffic delays in a pedestrian crossing area [7,8]: where Np та Nтр -respectively the intensity of pedestrian (ped/h) and automobile traffic (veh /h); v -speed of movement, km/h.
Second, in the current regulatory framework of Ukraine for the RSN design and operation there is no method of applying RSN design solutions of unregulated intersections. There is no assessment of its impact on the entire network operation, nor even individual criteria for such assessment.
Third, in the Ukrainian regulatory framework there is no assessment of individual transport, pedestrians, cyclists and public transportation for their mutual (comprehensive) impact on the intersection operation.
Based on the analysis of foreign literature and the regulatory framework, three indicators of the city RSN unregulated intersection operation were identified -traffic delay, queue length and load factor in the movement directions. Traffic delay is used in the United States and Germany as a key indicator of the efficiency of unregulated crossings.
However, when determining the movement delays by the "manual" method, there is a certain problem of inconsistency between the theoretical data (according to calculations [22]) and the data determined by the method [29].
Based on this, we can make some recommendations: -Further scientific and theoretical research with the introduction of correction factors of reduction in formulas (2-3) is needed; -Computer video processing method application to show the road situation in order to determine the traffic and pedestrians delays.