Using GIS to track traffic accidents

​Almost every day of the week, police officers are called to the scene
of a traffic accident to provide assistance. But how many times does a
police officer report to the same place twice? Moreover, do they
report to high traffic volume intersections more than smaller
residential streets for these accidents? These were the types of
questions the Police Department for the Village of Morton Grove aimed to
study. The Police Department wanted to analyze how many accidents were
happening every three months and where exactly were these accidents
taking place. Furthermore, they needed and easy method for displaying
these results so they could attempt to find out what was causing these
accidents to happen.

With these ideas in mind, the Police Department requested the
services of the Geographic Information System (GIS) Department. By
using the tools located within the GIS, each traffic accident that was
recorded by the Police Department could easily geocoded to a
geographical location. Geocoding is an operation that searches a street
or address data file and locates the coordinate where an address falls
on a particular street, in this case, the tool located the intersection
where the accident occurred.

Once the traffic accidents are located, they are placed on a map in
order to analyze where the most accidents arise as well as what time of
day the accidents occurred. Each time the map was created it used
different colored points to help the viewer depict if the accident
happened at night or during the day. A trend seemed to form near the
intersections of busy streets but it was still hard to see if there were
any “out of the ordinary” circumstances. For this reason alone, the
GIS Department recommended that at the end of each year the data be
represented as graduated symbols for the amount of accidents occurring
in the same location rather than single points for every single accident
(for example, large circles for a high accident count and small circles
for a low accident count). This made it easier to discern which areas
of town had the more accidents than other parts of the village and was
well received by the Police Department. By using this methodology, the
final map product was much easier to read and allowed the Police
Department to easily target which streets required more attention for
traffic safety studies.

Since the inception of this project, the analysis has been performed
every three months and all maps are immediately submitted to the Police
Department for review. Thus making it easy to see how recorded accident
reports from the Police Department’s records can be used with the tools
of the Geographic Information System in order to make graphical data
that can simply be analyzed.

Using GIS to track traffic accidents

​Almost every day of the week, police officers are called to the scene
of a traffic accident to provide assistance. But how many times does a
police officer report to the same place twice? Moreover, do they
report to high traffic volume intersections more than smaller
residential streets for these accidents? These were the types of
questions the Police Department for the Village of Morton Grove aimed to
study. The Police Department wanted to analyze how many accidents were
happening every three months and where exactly were these accidents
taking place. Furthermore, they needed and easy method for displaying
these results so they could attempt to find out what was causing these
accidents to happen.

With these ideas in mind, the Police Department requested the
services of the Geographic Information System (GIS) Department. By
using the tools located within the GIS, each traffic accident that was
recorded by the Police Department could easily geocoded to a
geographical location. Geocoding is an operation that searches a street
or address data file and locates the coordinate where an address falls
on a particular street, in this case, the tool located the intersection
where the accident occurred.

Once the traffic accidents are located, they are placed on a map in
order to analyze where the most accidents arise as well as what time of
day the accidents occurred. Each time the map was created it used
different colored points to help the viewer depict if the accident
happened at night or during the day. A trend seemed to form near the
intersections of busy streets but it was still hard to see if there were
any “out of the ordinary” circumstances. For this reason alone, the
GIS Department recommended that at the end of each year the data be
represented as graduated symbols for the amount of accidents occurring
in the same location rather than single points for every single accident
(for example, large circles for a high accident count and small circles
for a low accident count). This made it easier to discern which areas
of town had the more accidents than other parts of the village and was
well received by the Police Department. By using this methodology, the
final map product was much easier to read and allowed the Police
Department to easily target which streets required more attention for
traffic safety studies.

Since the inception of this project, the analysis has been performed
every three months and all maps are immediately submitted to the Police
Department for review. Thus making it easy to see how recorded accident
reports from the Police Department’s records can be used with the tools
of the Geographic Information System in order to make graphical data
that can simply be analyzed.