Model for Predicting Traffic Signs Functional Service Life – The Republic of Croatia Case Study

  • Dario Babić Faculty of Transport and Traffic Sciences
  • Darko Babić Faculty of Transport and Traffic Sciences, University of Zagreb, Croatia
  • Dragana Macura Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia
Keywords: traffic signs, retroreflection, traffic sign degradation, functional service life,


Traffic signs are the basic elements of communication between the relevant road authorities and road users. They manage, regulate, inform and warn road users to ensure their safe movement throughout transport networks. Traffic signs must be timely visible to all traffic participants in all weather and traffic conditions in order to fulfil their function, which means they must have satisfactory retroreflection properties. This paper presents a research of the deterioration of traffic signs retroreflection. The aim of this article is to develop models that will effectively enable predicting the retroreflection of traffic signs and thus optimize the maintenance activities and replacement of road signs to increase road safety. The research included measurements of retroreflection of retroreflective material Classes I and II (white, red and blue colour) and Class III (red and yellow colour). Based on the collected data from the City of Zagreb (Republic of Croatia), the authors developed the models to estimate the functional service life of certain colours and materials used to make traffic signs. Considering that the average coefficient of determination for all the models is between 0.55-0.60, they present an effective tool in the traffic sign maintenance system.

Author Biographies

Darko Babić, Faculty of Transport and Traffic Sciences, University of Zagreb, Croatia
Department for Traffic Signalization; Assistent professor
Dragana Macura, Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia
Railway department; Assistent professor


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How to Cite
Babić D, Babić D, Macura D. Model for Predicting Traffic Signs Functional Service Life – The Republic of Croatia Case Study. PROMET [Internet]. 2017Jun.27 [cited 2020Apr.4];29(3):343-9. Available from: