The weather affects road safety. Adverse weather conditions, in particular, not only decrease the road capacity but increase the crash risk by increasing the stopping distance. For this reason, it is most important to provide accurate weather information to road managers and drivers. Currently, road weather information is provided to road managers and drivers by using observation data from weather observation points managed by the Korea Meteorological Administration. However, weather observation points are located based on administrative districts, not road sections. Therefore, when providing road weather information based on weather station data, there is a risk that the actual road weather conditions and the provided road weather conditions are different.
Recently, with the development of intelligent transportation systems, it has become possible to collect various and accurate vehicle trajectory data in real-time. In this study, we suggested a method of collecting weather information on roads in real-time using wiper operation status information included in Probe Vehicle Data (PVD) collected every second. Also, to verify the accuracy of the proposed method, the agreement rate between the PVD wiper operation information and the actual rainfall information was analyzed. By using the method of collecting weather information on the roads proposed in this study, the problems arising from the current method of providing weather information can be solved
In order to compare and analyze the wiper operation information and rainfall information of PVD, first, error data that may be included in PVD was removed or corrected through pre-processing. And the data considered to be driving in a tunnel and the data with a vehicle speed of less than 10 km/h were eliminated from the analysis to exclude environments in which wipers do not function regardless of rainfall. Next, to compare the wiper information with the rainfall information, coordinate information included in the PVD was used to match the nearest weather collection points to the location of the vehicle. After that, we analyzed the consistency between the data by comparing wiper operation and rainfall at the same time zone.
The analysis found that the coincidence rate in non-rain time zones was 94 percent. The 6% inconsistency in the non-rain time zone result is estimated to be the result of non-rainfall related actions, such as washer fluid use. The probability of matching was 73 percent in the case of light rain, which was lower than in other rainfall ranges. The reason for this result is that it is highly likely that it has not rained yet or has already stopped raining when the vehicle passes through the light rainfall section. According to the analysis results, the higher the rainfall per hour, the higher the probability of matching.
FThe outcomes of this study are expected to overcome the limitations of providing weather information to existing roads and provide weather information to all future road networks where C-ITS data can be collected.