Shevchenko V. Determination of rational parameters of progressive traffic control on urban highways

Shevchenko Volodymyr Vadymovych. Determination of rational parameters of pro- gressive traffic control on urban highways. – Qualifying scientific work on the rights of the manuscript. Thesis for obtaining the degree of doctor of philosophy in the specialty 275 – Transport Technologies (by Automobile Transport). – Kharkiv National Automobile and Highway University of the Ministry of Education and Science of Ukraine, Kharkiv, 2023. The dissertation is devoted to the solution of the scientific and applied problem of determining the rational parameters of coordinated traffic control on city highways with a median strip. For this purpose, an analysis of existing approaches to determining the parameters of the operation of traffic lights and methods of building plans for trunk and network co- ordination of traffic lights was carried out. As a result, it was established that at this time there are no clear instructions on effective directions for the development of traffic light coordination systems in cities, and the majority of works are devoted to the adjustment of adaptive traffic light objects to ensure an adequate reaction of traffic lights to the dynam- ic nature of traffic flows, including in networks, where local traffic lights operate at adja- cent intersections with pre-timed cycles. Road traffic control guidelines of various coun- tries suggest using a space-time diagram of linear coordination to create coordination plans, although they recognize its oversimplified nature and do not provide clear recom- mendations regarding the specifics of its practical use. Another option for coordination is to use existing hard or adaptive coordination software, which also use simplified models to create coordination plans. At the same time, the transition to the coordinated operation of traffic lights in the transport systems of Ukrainian cities is the most accessible direc- tion for the development of traffic light control. This indicated the need for the creation of a new method of forming highway coor- dination plans, which should take into account the peculiarities of this process, which consist in the group arrival of vehicles from the green wave pack to the next intersection, the presence of vehicles that complement the green wave pack starting from the second intersection sections and additional possibilities in setting up the coordination plan, which ensure the presence of a separate lane on the section and traffic light cycles of cycles with a left turn allocated in a separate phase. The two-stage procedure for creating a coordination plan on an urban highway de- veloped in the study takes into account the peculiarities of the group arrival of a green wave packet to the next regulated intersection on the coordinated urban highway section and allows to bring the final solution of this problem closer to the global minimum of the waiting time for the possibility of passing through the regulated intersection. An analytical model of delays at a controlled intersection, created in the work un- der the condition of full departure of the queue of cars during the permission signal, al- lowed to determine the limiting level of loading of the secondary approaches to the city highway with coordinated control, which should be used in the construction of the coor- dination plan. With the help of a simulation experiment, it also allowed to substantiate the possibility of using Webster's delay formula at the first, analytical stage of plan construc- tion. The estimation of the probability of the occurrence of an incomplete pack of cars under coordinated control on an urban highway led to an analytical dependence that coin- cided with a similar probability in a standard single-line mass service system with a standard FIFO service discipline and with an exponential service time distribution law. Thanks to this, the dependence of the desired probability on the load expanded the range of application to adjustable traffic lights and, due to its inverse linear nature, made it pos- sible to get rid of restrictions on the choice of the size of the bundle and to do it based solely on the considerations of minimizing the delay time of traffic participants when overcoming a coordinated section of the city highway. A fragment of one of the central thoroughfares of the city of Kharkiv, avenue Sci- ences, from Nezalezhnosti Ave. to Minskaya St., which has a dividing strip, sufficient length and number of traffic lights. On it, there is a constantly high traffic intensity during the busy daytime period of the working day, which leads to a high level of loading of most approaches to regulated intersections and, accordingly, to significant delays when crossing it.