1. Mobile friction observations and thermal mapping in Testbed area Helsinki Testbed mesoscale course Toni Hellinen and Marjo Hippi

2. Motivations Interest of using new equipments Researching the spatial fluctuation of road temperature and friction Finding the sensitive places of road slipperiness Identification of different weather phenomena that cause slipperiness on roads

3. Vaisala Remote Road Surface Condition Sensor DSC111 Remote surface state sensing Measuring thickness of water ice slush snow or frost layer friction coefficient (0-1) Parallel use with remote temperature sensor Both attached to vehicle

4. Observations Mobile measurements from ColdSpots project data Comparable data from road weather stations in Testbed area Mobile measurements were done in interesting weather situations Thawing period Snowing period Cold slippery (surface temperature below -7 C and light snow) Slush period

5. Map of the area (Vt1)

6. Case study Vt1 23.1.2007

7. Radar data 23.1.2007 15:30 UTC

8. Conclusions Research three different occasions Vt1 23.1.2007: Snowing Vt6, Vt7 26.1.2007: Thawing and snowing Vt6, Vt7 27.1.2007: Slush Comparing optical friction and temperature measurements to road weather observations and radar data