The analysis of scientific publications and timetable models is given. Existing works have been used as a basis of a classification of timetables by the frequency of time values. The urban transport network is presented in the form of a multigraph. The transition from a multigraph of the urban transport network to a network of events characterizing the traffic process is considered. Constraints on time values have been formalized to solve the main problem of the scheduling theory. The proposed formalization factors in the specifics of traffic management planning in Russia and other post-Soviet countries. A mathematical model of aperiodic timetables for the ground urban electric transport traffic based on the theory of linear programming is presented. The optimization criterion for solving the main problem of the scheduling theory has been substantiated. The uniformity of traffic intervals is used as an optimization criterion for solving the main problem of the scheduling theory. The article provides tabular timetables used in urban transport to describe the traffic process in the absence of significant events on the line. The implementation of the model presented in this article is exemplified by the automated tram and trolleybus timetable design software being part of the automated urban electric transport control system currently used in Saint Petersburg to form tram and trolleybus timetables. The examples of calculating the vehicle departure interval diagrams have been used to demonstrate the function of aligning the traffic intervals. In conclusion, the advantages and development paths of the proposed model of aperiodic timetables for the ground urban electric transport traffic are listed.
Urban transport, ground electric transport, timetable, aperiodic timetable, linear combination, automated tram and trolleybus timetable design system, automated urban electric transport control system