Evaluation of Errors in Road Signs in a Long Roadwork Zone Using a Naturalistic Driving Study

The paper presents an application of a new, simple approach for the naturalistic assessment of road sign quality from a driver’s perspective, using dashboard camera recordings. This method was used to evaluate signage along a 69.6 km road construction zone in Poland associated with the phased upgrade of a dual carriageway with unlimited access into a motorway. The analysis focused on three distinct phases of the roadwork: the beginning of roadwork, the progress of roadwork, and finishing roadwork. The correctness, visibility, and quality of the road signs were assessed on a specially developed scale. The study found that 1135 road signs were unnecessary, which was equal to 36% of all signs. The majority of all signs (48.1%) indicated prohibition: more than one third (33.6%) of them were speed limit signs, of which 52% were posted without the need. It was demonstrated that the simple method applied in this study can be considered a useful tool to identify deficiencies in signage, which could ultimately improve road safety and make road management more sustainable. Moreover, this study confirmed again that the use of appropriate video recordings makes it faster and easier to conduct an inventory of road signs.