Abstract: The subject of this research is the theory and practice of assessing transport accessibility of the territories of northern regions, where the absence of all-season overland communications render impossible their comparison and analysis. The common type of communications in northern regions are winter/ice roads, which are not usually included in analysis of infrastructure and transportation accessibility of a territory. Inclusion of the variable of seasonal communications is substantiated by the absences of alternatives in northern regions. The tools for assessing transport accessibility of the territory are developed using the integral index method, which allows determining the differentiation of variables of weighted average time and monetary costs on freight transportation. Such method based on the cost and time assessment of the transportation-logistical expenses allows accounting for changes in the transport complex, related to development of transportation network in the region, reflected on all stages of the logistical process. The developed methodological toolset is based on the classic methods of assessment of regional transportation system, while at the same time presents novelty, as it includes the presence of seasonal types of transportation communications in northern regions of the country and their logistical component, allowing to fully assess the peculiarities of transportation systems in the northern regions. The conducted analysis of the variables of the territorial structure of transportation network of the Sakha Republic (Yakutia) revealed heterogeneity in transport accessibility of municipal regions of the Sakha Republic. Results of the analysis of the level of differentiation of transport accessibility of municipalities through methods demonstrated a heterogenic differentiation, influenced by the vastness of the territories, low density of population, as well as sparseness of settlements of the Artic regions among number of other factors.