Road markings provide drivers with the information necessary for their comfortable and safe journey. To achieve that, they must be visible in all driving conditions, which means that they have to be renewed and maintained in a timely manner. This research aims to develop a model for predicting the service life of paint, thermoplastic and agglomerate cold plastic road markings. The research comprised 5218.00 km (115 roads) of solvent-borne paint road markings, 579.00 km (30 roads) of thermoplastic and 4979.00 km (30 roads) of agglomerate cold plastic road markings. The retroreflectivity of road markings was measured two times (after renewal and after winter) using the dynamic measuring method. Service life prediction model was developed for each material based on factors such as initial retroreflectivity, road marking age and position, annual average daily traffic and winter maintenance activity of the road. Developed models were tested using a new data set, and all three models showed satisfactory accuracy. The application of the model enables road authorities to optimise road-marking maintenance activities, while at the same time, ensuring the level of visibility required by drivers.

Traffic sign visual information provides road users with the basic instructions regarding route selection, safety at intersections, warnings on physical obstacles on the road and safe route marking. The use of sophisticated eye tracking systems is an efficient way to analyse the influence of traffic signs on drivers’ behaviour. In this paper, the drivers’ perception of traffics signs has been analysed using such a system. The aim of this paper is to determine how the perception of traffic signs changes according to the frequency of driving on a specific route or according to the route familiarity. The results show that the drivers’ perception of traffic signs declines as they get familiar with the route and road conditions. In addition, older drivers having more driving experience perceive fewer signs and elements from the environment because they are often led by their own experience and knowledge, so they do not need the same amount of information as compared to younger drivers.

Road markings quality control implies conducting several different tests, of which the most significant are visibility tests comprising daytime and night-time visibility measurements by applying the static or the dynamic measuring method. Although the dynamic test method allows measuring the visibility along the entire road section and thus provides a more complete and objective evaluation of road markings quality compared to the static method, it does not measure daytime visibility, for which both the European and the national directives define the minimum requirements. The purpose of this paper is to examine the correlation between daytime and night-time visibility based on static measurements conducted on state roads in the Republic of Croatia. The correlation analysis determined that the strength of relationship between daytime and night-time visibility, is relatively weak. Despite being relatively weak, the relationship still exists, which was the reason for conducting a further analysis. In the analysis, a unique coefficient was obtained through the ratio of retroreflection value and daytime visibility value for all the measurements. The unique coefficient was basis for development of a model that will be able to calculate the daytime visibility based on the results of the dynamic measurements of road markings night-time visibility. The authors evaluated the model with a t-test and concluded that the accuracy of the model is statistically satisfactory.

Road markings are an important component of delineation, intended to provide guidance and warning, to manage and regulate road traffic. In order to properly fulfil their function, road markings must be visible and it is precisely the visibility, in terms of road safety, that presents their most important characteristic. Practical tests showed that the marking visibility, or retroreflectivity, changes depending on directionality, showing higher values in the direction the marking is applied than in the opposite direction. This paper addressed the impact of road markings directionality on their retroreflectivity using the dynamic method for testing retroreflectivity. The research considered paint, thermoplastic and structural markings made of cold plastic. The results showed that the impact of directionality of paint and flat thermoplastic markings on their retroreflectivity is negligible. The average difference in retroreflectivity of renewed paint markings is 13.1 mcd/m 2 •lx and 11.85 mcd/m 2 •lx for existing paint markings, while the respective difference concerning flat thermoplastic markings is 9.60 mcd/m 2 •lx for renewed markings and 9.20 mcd/m 2 •lx for existing markings. A more significant difference was noted with structural markings made of cold plastic, namely 62.80 mcd/m 2 •lx for renewed markings and 49.60 mcd/m 2 •lx for existing markings. The results for paint and thermoplastic markings show that directionality should not be taken into consideration when evaluating their quality, which greatly facilitates and simplifies the process of testing the markings retroreflectivity. The stated results are of great importance for traffic safety and markings maintenance system.

Traffic signs as part of the overall traffic signalization system convey a message to road users using shapes, colours, text and symbols. They inform road users about regulations, warnings, directions, and guidance in traffic systems, in order to ensure safe traffic flow. In conditions of low visibility drivers receive less visual information in traffic which makes the perception of the surroundings, and thus the driving, significantly more difficult. In order to overcome the mentioned problems traffic signs must have satisfactory retroreflection properties and be properly positioned and maintained. Given the number of traffic signs on the roads, it is necessary to optimize their maintenance activities. The aim of this study is to develop a model for predicting the state of traffic signs regarding their retroreflective values based on their age. The study included 21,467 traffic signs on 30 state roads throughout the Republic of Croatia. Linear models for predicting state of signs were developed using binary logistic regression for each class of retroreflective material. Even though the models very accurately predict when the signs meet minimal prescribed retroreflection values for all the three classes of retroreflective material, they have certain downsides when predicting when the signs are not valid, i.e. do not meet minimal prescribed retroreflection values. Although the developed models did not show satisfactory accuracy, they represent unique prediction models of traffic signs functional service life, enabling prediction without conducting previous retroreflection measurements which, considering the number of in-service traffic signs, thus enables the optimization of the traffic signs maintenance system.