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Effects of road wetness. Supresses suspension + direct emissions of salts and dust Up to almost 100 % Increases depot of PM Increases direct road wear Factor 2-3? Decreases tyre wear ?. Factors influensing the street wetness. Precipitation Rain/snow Amount Temperature
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Effectsof road wetness • Supresses suspension + direct emissions of salts and dust • Uptoalmost 100 % • Increases depot of PM • Increasesdirect road wear • Factor 2-3? • Decreases tyre wear?
Factorsinfluensing the streetwetness • Precipitation • Rain/snow • Amount • Temperature • Air/road • Relative humidity • Solar radiation • Wind speed • Wind causes the street to dry up faster • Road salt and dust binding • Salt bind moisture to the street • Keeps the street wet for longer periods • Traffic amount • Vehicle speed • Drainage • Street slope • Pavement texture
Whatcanwelearn from road surfacewetnessmeasurements? • Areal variation of wetness on a street • Rate of drying up on different spots of a street • Variation between different streets • Impact of • Street direction • Vehicleamount/speed/composition • Compare with calculated road wetness • Dynamics ofwetnesschanges
Road surfacewetness sensorsHornsgatan 5.10 m 3.50 m 6.60 m
Data available • Hornsgatan, street canyon, ca 30 000 veh/day • 3 sites, Period • Sveavägen, street canyon, ca 30 000 veh/day • 3 sites, Period • Norrlandsgatan, street canyon, ca 10 000 veh/day • 2 sites, Period • Folkkungagatan, , street canyon, ca 30 000 veh/day • 3 sites, Period
ExampleHornsgWetness + PM10 localcontrib Shows CRUCIAL to describewetnesscorrectly! Middle of road (1) less important! 3 1 2 Delta PM10
Later in the year less difference in road wetnessbetweensites
October 2009 March 2010 Long period of wet roads before
March 2007 Blue best to describe PM10 Feb 2008
Hornsgatan 29th and 30th Jan 2011 Hornsgatan 29th and 30th Jan 2011 2 3 1 Still wet in depot
Sveavägen 29th and 30th Jan 2011 Everything wet Onlydrivewaydry, Depot still wet
Sveavägen 29th and 30th Jan 2011 Drydaytime, with traffic Still wet Dry, butlittletraffic
E4/E20, 26th and 27th Jan 2011 Onlydry in the wheeltracks. Still wetbetweenlanes.
Streetdirectionmay be important Hornsgatan Sveavägen Norrlandsgatan
Comp of wetness on different streets Feb 2009 Hornsgatan Sveavägen March 2009
Nov 2009 Mar 2010