Dot distribution map

www.tfhrc.gov/pubrds/03nov/01.htm

Dot distribution maps, such as the one above, are useful because they are able to provide more "specific" information about a certain topic, in this case the number of concrete slab bridges. Dot distribution maps are able to show a very large scale area and then pinpoint if, and how many, of a type of group there is. One important advantage to this type of map is that it is much easier for a reader to understand this type of map because instead of always constantly having to look back to a legend and see which color or pattern relates to what kind of density, they will simply be able to see by the number of dots and how clustered they are.