ID: 26 Sirwec 2008, Prague, 14 - 16 May 1 Development Project ColdSpots: Towards More Detailed Road Condition Forecasts Marjo Hippi 1 , Pertti Nurmi 1 and Pirkko Saarikivi 2 1 Finnish Meteorological Institute, Finland Email: marjo.hippi@fmi.fi Email: pertti.nurmi@fmi.fi 2 Foreca Consulting Ltd, Finland Email: pirkko.saarikivi@forecaconsulting.com ABSTRACT The objective of the three-year project “ColdSpots” (2005-07) was to improve present road weather and condition forecast methods and models by establishing and utilizing a novelty database which covers detailed local information on problematic road sections in Finland. A wealth of information has long been available in various databases, such as registers of road structures and traffic accidents, feedback on road maintenance activities and quality control data. However, this information has been unavailable to the developers of weather forecast models, until now. ColdSpots was initiated in 2005, with first analyzing the available road weather information and compiling the necessary databases. During the second phase, 2006- 07, problematic local road weather features and possibilities to improve road weather modelling were studied. On the second part mobile temperature and friction measurements were carried out along the highways. Mobile measurements revealed valuable information about prevailing circumstances along the roads whereas traditional fixed road weather station network reveals information only for specific spots. There can be found several features affecting to the local road condition. Prevailing and past weather, environmental features and road construction affects to the local road weather. Also, traffic and road maintenance activities can change the road condition. Keywords: Road weather modelling, road weather observations, mobile measurements, friction. 1. INTRODUCTION Road condition can vary much along road stretches and that can cause tricky driving circumstances for drivers. Learning how the circumstances vary along the road stretches and what cause the variations it is possible to improve road weather forecasts and optimize road maintenance activities. Project ColdSpots was started after serious winter time accidents in Finland. In the first part of ColdSpots project the slippery and dangerous road stretches were collected to the database [1]. That information was collected by asking for road maintenance personnel who have a lot of hands-on experience. The database was fulfilled with the information of winter time car accidents. A test set of some fifty most problematic locations were selected for the ColdSpots places. On the second part of this project local road weather features were studied and field measurements carried out along the highways [2]. Also, possibilities to improve numerical road weather models were researched. The aim of this project was to study how the circumstances like friction, state of the road and road surface temperature vary along the road stretches. By understanding reasons affecting to the local road weather it could be possible to do better road weather forecasts for places which are susceptible for slipperiness. This project was done in co-operation with two Finnish weather partners Foreca and Finnish Meteorological Institute and an infrastructure service company Destia (formerly Finnish Road Enterprise).