33 Characteristics and Mitigation of Vehicular Non-Exhaust …
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model has been evaluated against air quality data by [1, 2] and they found the model
to predict the PM 10 concentrations within the range of ±35% of the observed values.
In this work we used the NORTRIP model to estimate and study the PM 10 and PM 2.5
emission factors separately for different climatic zones, road and street categories,
and road maintenance policies in Finland. To achieve this task, a range of input
data and parameters were established. During the work we found out several missing or incomplete input data sets, especially regarding traffic and road maintenance
activities.
Model input data was developed for road and street configurations and traffic data
(traffic volume, vehicle types and driving speed) based on national Digiroad (https://
www.liikennevirasto.fi/web/en/open-data/digiroad) and LIPASTO (http://lipasto.vtt.
fi/en/index.htm) databases. In Finland winter tires are compulsory during mid-winter
and studded winter tyres are very popular with traffic shares from 76 to 94% depending on the region. Studded winter tires are allowed from 1st November until the
first Monday after Easter, but this period may vary depending on weather conditions.
Meteorological data concerning wind speed, temperature, radiation, cloud cover, and
humidity was collected from representative weather stations from the five climatic
zones in Finland. Road maintenance activity data, including information about addition of salt and sand to the road surface, were developed with an automatic traction
control (sand and/or salt) module of the model according to predefined rules that
were set using current real-life practices in the road and street network.
We calculated hourly level emission factors with the NORTRIP model for the
period January 2008 to December 2011 for each street/road category and climatic
zone combination with current road maintenance practices. The model was also used
to calculate emission factors in three policy scenario groups designed to simulate the
impact of measures intended to reduce non-exhaust PM emissions:
(1.) “Limiting dust generation” scenario group focused on (1.1) reduction of studded
tyre usage or wear effect in cars in three cases: current use (about 80%), 50%
usage and 20% usage, and (1.2) limiting the use of traction sanding in different
urban settings.
(2.) “Efficient and early cleaning and dust binding” scenario group applied additional extensive cleaning or extensive cleaning and dust binding with state-ofthe-art machinery for highly trafficked streets.
(3.) “Maximal reduction” scenario that applies the early cleaning and dust binding
criteria with a 20% studded tyres share.
33.3 Results
Annual average non-exhaust PM 10 and PM 2.5 emission factors were estimated for
the climatic zones with the currently used road maintenance practices in Finland
(Table 33.1). The values in Table 33.1 are for the whole fleet; for only the light duty
traffic the emission factors were approximately 60% of the presented values. The
213
model has been evaluated against air quality data by [1, 2] and they found the model
to predict the PM 10 concentrations within the range of ±35% of the observed values.
In this work we used the NORTRIP model to estimate and study the PM 10 and PM 2.5
emission factors separately for different climatic zones, road and street categories,
and road maintenance policies in Finland. To achieve this task, a range of input
data and parameters were established. During the work we found out several missing or incomplete input data sets, especially regarding traffic and road maintenance
activities.
Model input data was developed for road and street configurations and traffic data
(traffic volume, vehicle types and driving speed) based on national Digiroad (https://
www.liikennevirasto.fi/web/en/open-data/digiroad) and LIPASTO (http://lipasto.vtt.
fi/en/index.htm) databases. In Finland winter tires are compulsory during mid-winter
and studded winter tyres are very popular with traffic shares from 76 to 94% depending on the region. Studded winter tires are allowed from 1st November until the
first Monday after Easter, but this period may vary depending on weather conditions.
Meteorological data concerning wind speed, temperature, radiation, cloud cover, and
humidity was collected from representative weather stations from the five climatic
zones in Finland. Road maintenance activity data, including information about addition of salt and sand to the road surface, were developed with an automatic traction
control (sand and/or salt) module of the model according to predefined rules that
were set using current real-life practices in the road and street network.
We calculated hourly level emission factors with the NORTRIP model for the
period January 2008 to December 2011 for each street/road category and climatic
zone combination with current road maintenance practices. The model was also used
to calculate emission factors in three policy scenario groups designed to simulate the
impact of measures intended to reduce non-exhaust PM emissions:
(1.) “Limiting dust generation” scenario group focused on (1.1) reduction of studded
tyre usage or wear effect in cars in three cases: current use (about 80%), 50%
usage and 20% usage, and (1.2) limiting the use of traction sanding in different
urban settings.
(2.) “Efficient and early cleaning and dust binding” scenario group applied additional extensive cleaning or extensive cleaning and dust binding with state-ofthe-art machinery for highly trafficked streets.
(3.) “Maximal reduction” scenario that applies the early cleaning and dust binding
criteria with a 20% studded tyres share.
33.3 Results
Annual average non-exhaust PM 10 and PM 2.5 emission factors were estimated for
the climatic zones with the currently used road maintenance practices in Finland
(Table 33.1). The values in Table 33.1 are for the whole fleet; for only the light duty
traffic the emission factors were approximately 60% of the presented values. The