Modern urban public transport should have: quality service, environmental and operational safety, high reliability and performance, a quality system of maintenance and repair, high profes-sionalism of drivers and maintenance personnel. The article discusses the features of the operation of public transport in Yerevan, the issues of improving operational reliability and adjusting the frequency of replacement of operational materials. Using the RSTAT software package, the statis-tics of failures and operating time of GAZEL minibuses (about 1400 pcs.) For Yerevan routes, characterized by a sharp relief contour and traffic intensity, were processed and their correspond-ence to the Weibull distribution was processed. The histograms and curves of the distribution func-tions of the failures of the gearboxes and the rear axles of the minibuses were constructed, and the optimal maintenance numbers and operating time values were determined.