Evaluation of the Road Weather Information Service in winter 1999-2000
Evaluation of the Road Weather Information Service in winter 1999-2000. Anttila, Virpi; Nygård, Magnus; Rämä, Pirkko. 2001. Tiehallinto, Liikenteen palvelut - yksikkö, Helsinki. 79 s. + liitt. 16 s. Tiehallinnon selvityksiä : 41
The Road Weather Information Service is a traffic information service in Finland. The service has been developed jointly by the Finnish National Road Admini-stration, the Finnish Meteorological Institute, the Central Organisation for Traffic Safety in Finland, the Finnish Motor Insurers' Centre and the Finnish Broad-casting Company. The purpose of the service is to forecast the road conditions for next twentyfour hours. There are three categories of Road Weather Information for conditions on roads: "normal", "poor" and
"hazardous". The classification is based on existing and predicted road conditions, weather and maintenance operations.
The aim of the evaluation study was to assess how well the service has suc-ceeded and how far its objectives have been met. The study evaluated how well drivers recognised the Road Weather Information Service, the accuracy of the information given, and expert opinions about the service. Methods included in-terviews with drivers and experts and review of data on traffic accidents.
The Road Weather Information Service has been in place for 3 years. The serv-ice was well recognised among drivers: During a telephone interview over 90% (n = 1009) of them said they recognised the service when it was described to them. Most of the drivers (76%) found the service useful compared with regular weather forecasts, and 77% of the drivers said they used the service's informa-tion almost daily during the winter season. However, the content and road weather categories used by the service were not as well known. Only 33% of drivers who recognised the service without being helped knew that it gives in- formation on poor/hazardous road conditions.
Over 40% of drivers considered evenings as the most important time to receive the service's information, indicating that road weather information is also used a lot for planning the next day's trip. When asked to grade the accuracy of the service's information on a scale of 4-10, over half the respondents gave a score of 8 or more (mean 7.9). Over 90% of drivers agreed that the service had warned of both poor and hazardous road conditions accurately.
Most drivers felt that the Road Weather Information Service had a considerable effect on their driving behaviour - only 6% did not find the information to affect their driving behaviour at all. The greatest effects were on driving behaviour in general (overtaking, speed etc.), time reserved for the journey, and time of de-parture.
During the winter season of 1999-2000, 63% of the time the forecast for road weather was normal, 33% of the time it was poor, and 2% of the time hazardous. The aim of the service is to warn drivers about the most hazardous conditions, when the number of traffic accident tends to double or even treble. On average the classification succeeded quite well.
However, especially in coastal areas rapid changes in weather and road conditions were difficult to predict in sufficient time. The day with the most traffic accidents was accurately forecast - all areas in the country where many accidents occurred had classified the road conditions as "poor" or "hazardous".
Road Weather Information Service forecasters were asked to provide improvement proposals and ideas for developing the service further. Most of them said that compared to earlier years less frequent contact between the Road Administration and the Meteorological Institute was a negative aspect that needs improving.
