In the first phases of study and design documentation of rural roads, one of the key parameters to determine in the analyses is the Design Hourly Volume (DHV). The required level of service and the feasibility of the project depend to a large extent on a properly established DHV. Essentially, the problem is to determine the value of the K-factor for a certain nth highest hour of the year.
This paper points to the need for additional analysis of existing databases of long-term automatic traffic counting, from which the necessary guidance for planners and designers can be derived, enabling them to understand and apply the K-factors in a clearer and more detailed way. Using specific data examples, characteristic sections of rural roads with different functions and types (seasonal variations) of traffic demand were selected to show significant differences in the values of the K-factors for the same selected nth highest hour of the year. Several guidelines (BiH, Slovenia, Croatia, Italy, Serbia) were analysed beforehand to get a better understanding of how the K-factor or DHV is explained and used in different countries. The main objective of the article is to show that, on the basis of the existing databases of continuous automatic counting in these countries, with additional analyses presented in this paper or in a similar form, significant regularities in determining the DHV can be achieved, eliminating difficulties of application in engineering practice.
As all guidelines practically recommend the use of HCM in capacity analyses, specific examples are selected to show the difference between the definition of HCM for a route with dominant recreational traffic and our route with dominant tourist traffic (recreational versus tourist).

K-factor, DHV, measure of seasonal variation