Methodology and criteria for determining annual average daily traffic (tpda) from manual classified counts, case study, Nicaragua

Abstract

The determination of the growth rate of vehicular traffic is the main variable in the calculation of Equivalent Simple Load Axes required for the design of pavement thicknesses and other applications of traffic engineering. In Nicaragua, traffic statistical yearbooks, published by the Ministry of Transportation and Infrastructure, have limited data because they do not include the entire road network, so it is necessary to perform manual gauging and, based on the analysis of dependency and correlations, determine the  projected traffic for the classified counts performed. Due to traffic characteristics, post COVID impacts and available data, it is necessary to establish criteria for the selection of growth rates.  This article, based on a case study, proposes a methodology for the inclusion or exclusion of values for analysis as well as a procedure based on recommendations of national regulations, analysis of historical and current traffic data as well as macroeconomic variables.