## 1 Introduction and Background
In particular, the approach to determine the probability that a lane change occurs due to an overtaking manoeuvre on the highway, which can be a conflict manoeuvre before a traffic accident, was investigated [30]. This manoeuvre is also influenced by other traffic conditions [31; 32], as well as the environment [18]. These researchers all determined how the factors of day and night affect the distribution of vehicle flow in lanes or, as one could also say, the overtaking of vehicles on a unidirectional multi-lane carriageway. They found that, at night, drivers use only one lane, which is understandable and mostly related to the low traffic volume (traffic demand). In adverse weather conditions, drivers are significantly more reluctant and careful when changing lanes. They take more time to make decisions [33], which can have a corresponding positive or negative effect on the capacity utilisation of the carriageway. The AHTMS currently determines the occurrence of traffic instability through a calculation of the standard deviation of vehicle speeds at a given equivalent traffic flow rate within the measuring time interval in the carriageway and overtaking lane--also referred to as the \"left lane\" or \"lane 2\" [34; 35; 36]. This happens when there are vehicles in the overtaking lane with high speeds that are well above the time mean speed. Another reason for the occurrence of such a traffic situation relates to slower vehicles, usually Heavy Goods Vehicles (HGV). In European countries, the maximum speed on highways is set administratively and is different for heavy vehicles than for light vehicles. On multi-lane highways, this phenomenon is manifested by a constant change of traffic lanes or a change in the lane distribution of traffic flow rates, as well as a change in the density and speed distribution across the lanes [15]. To prevent or mitigate the consequences of such traffic flow, the following traffic control measures in traffic lanes can be used:  
* Prohibit the driving of slow vehicles (usually heavy trucks and buses) in the overtaking lane, introduce a combination of \"minimum speed\" traffic signs in individual lanes (e.g., 110 km/h in the left lane--lane 2 and 80 km/h in the right lane--lane 1), or install \"no overtaking by HGVs\" traffic signalisation [37];Additionally, display the limit of the generally permitted speed as a preventive measure or limit the speed on the carriageway by one level;
* Advise drivers to adjust their speed to the traffic flow; the AHTMS uses arrow signals on VMSs to encourage the same direction of travel without changing lanes and, if necessary, set a minimum speed limit for each lane;
* Advise drivers to drive according to the driving rules, first in the right lane and then in the overtaking lane, when such a manoeuvre is required (e.g., message \"left lane: overtaking only\" for the case of the right-hand traffic rules). Common problems related to efficiency in some EU countries have already been addressed [35; 38], but Slovenia and some other similar countries in the region are characterised by heterogeneity and multiculturalism of drivers and rapidly changing weather conditions. There is a research gap in understanding how lane traffic control is affected by different weather conditions. A summary of the empirical research is presented in Section 2. On the basis of the data from the test sites, the traffic flow characteristics were determined by traffic lanes. We performed pre-processing and verification of input data collected from various traffic sensors and Road Weather Stations (RWS). Since we were interested in the lane distribution of traffic flows during the period when the traffic flow was not yet condensed, we excluded some data from the analysis. Thus, we excluded all data from the periods of peak load and the periods when congestion occurred. Similar pre-processing was also performed on RWS environmental data.