The paper conducts a survey of satisfaction level of users of two lane road in regards to constructional-geometrical factors influencing unimpeded traffic and influence of human element during its maintenance. Establishing the satisfaction level of users of existing road network is the primary goal of the paper, through the definition of Level of Service of relevance for the analysis of traffic of interurban road network. The survey was conducted on the road section Koprivna – Modrica, regional road R-465 (Busletic - Modrica). Using a questionnaire, the values of influence to the level of users’ satisfaction were established. Traffic infrastructure and elements of horizontal road signs have been identified as two main indicators giving negative grade to the level of satisfaction. The end of paper gives a review of measures for the improvement of existing conditions.

The main objective of this paper, based upon the extensive empirical research of free flow in local conditions, is to quantify the unfavourable impact of the flow structure on the road capacity using PCE (Passenger Car Equivalent) values as a function of longitudinal grade. Based on literature reviews and empirical research, it has been proved that the PCE value for all vehicle classes is directly correlated with the road gradient. The PCE values in free flow conditions have been determined for the approved vehicle classes. Based on the measured values, models for determining the average PCE value depending on the upward grade on two-lane roads have been developed. Comparison of the developed models in conditions of free traffic flow with the Highway Capacity Manual (HCM) models has shown lower PCE values in this research. Models for the percentage of PCE values PCE15%, PCE50% and PCE85% have also been established.

The biggest wealth of every country lies in its transportation infrastructure so the protection of negative impacts on infrastructure must be provided. The progress of sensor technology proposes today several types of weigh-in-motion systems, which have been tested for their efficiency, accuracy and cost-effectiveness. Technologies of piezoelectric sensors, bending plates and load cells are used for a number of applications comprising weigh enforcement, traffic data collection, bridge and toll control systems and so on. Advantages of using WIM technology are various and its benefits affects all road users (transport companies, public, public transport authorities). Potential of WIM application has been recognized in the leading EU countries, so the existence of the numerous WIM projects.