The negative effects of air
pollution on the human health on human beings are well
known, from minor and temporary troubles to a number of serious respiratory
illnesses. Persons with respiratory
illness (asthmatics) have even more increased sensitivity to air pollution. The
society has a major cost in all reporting sick and persons on disability. Calculations
show the cost even will increase in the future. Nitrogen dioxide from road
traffic is one of the major local air pollutants that affect the human health.
One way to decrease the
emissions from the road traffic and traffic jams is to try to influence the
traffic flow at certain times of the day, or to redirect it to other roads.
There are different ways to rearrange the traffic, voluntary or “by force”. One
voluntary way is to show the road-users the concentration of the air pollution
they are exposed to at given times and locations. This could be done by a short
time NO2 concentration forecast from road traffic, presently and 1-6 hours ahead. As a GIS based
forecast, Internet produced, it can be used to assist drivers when they plan their
journey: At what level is the air pollution right now and will it increase or
decrease during the following hours? This way a driver may plan his/her journey
in terms of time choice of route, to get as little exposure as possible. One
alternative calculation is to estimate the shortest / fastest route, to reduce
the exposure as much as possible, or perhaps a combination of the two. A
forecast like this might result in road users choosing a smarter way to travel
and to produce less emission to the atmosphere.
A forecast system like this
needs a lot of in parameters for a trustworthy output.
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Figure 1 City map of Göteborg
with NOx levels in the streets.
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The
concentration of air pollution in urban areas depends mainly on local road
emission and meteorological factors as wind velocity and wind direction. A good quality weather forecast important as an input to the
dispersion model. A forecast 12 hours
ahead will make it possible to plan the morning journey in the evening. Also data on the typical
traffic variations during the year / month / week and weekdays or holidays for
the different streets are needed as input. Data on intensity of traffic in real
time, coming from traffic sensors can also be used as input to such a
forecasting system. The intensity can be compared to the statistical traffic
variation and a forecast of traffic intensity can be calculated. The traffic
sensors also detect the speed of the vehicles, of importance since it affects
the emissions from the traffic flow.
Our vision is to have a
website as a useful tool where road users use this map for planning there
travels in Göteborg to avoid high levels of air pollution. A first step could
be to produce stationary maps for the morning and afternoon rush hour to
publish at the Internet. |