Bethel ME Overweight
FHWA Type 10 Eastbound 2001
The JOHO image above is an example of the use of American
Image Inc.'s innovative visualization technique. Using JOHO,
you can make displays from your large traffic information bases. You can quickly
discern patterns and exceptions to the patterns, even in the large data sets
produced with vehicle sensors.
Please see the description of the South Portland November image for a
more detailed description of JOHO image concepts.
This image shows the total number of overweight (exceeding 100,000 lbs)
eastbound FHWA Type 10 (3-axel trailer) trucks passing the WIM sensor in Bethel,
Maine for every hour in 2001. The image contains 8,760 data points. This is far
more information than traditional graphics programs can display.
Image Layout
The image has twelve panels, each showing one month in 2001, starting in the
upper left and ending in the lower right. As labeled on December’s panel, the
24 cells in the top row of a panel represent the hours in the first day of the
month. The bottom row of cells represents the last day of the month. The time
through each day is measured horizontally along each row, from the hour
beginning at midnight on the left to the hour beginning at 11 PM on the right.
Noon is halfway across the panel.
Each colored cell indicates the total number of overweight eastbound Type 10
trucks passing the sensor at that day during that hour. The legend at the right
indicates the relation between color and number of vehicles. The image indicates
counts of fewer than 3 trucks as the dark blue color at the bottom of the
legend. At about 7 vehicles the color changes from green to orange. The white at
the top of the legend indicates a count of 15 vehicles or higher.
Image Interpretation
The most obvious pattern for these overloaded trucks is that most of the
eastbound traffic is in the hours from 11 AM until about 4 PM on weekdays. At
this site there is significant variation with season. The busiest times are
July, August, and early October.
Note that after September 11 there is a significant drop in the traffic that
lasts until the beginning of October. It
is possible that the October increase is “making up” for the September
decrease.
The large number of eastbound overloaded trucks is due to the presence of a
paper mill east of the WIM site. Most of the overloaded trucks are probably
carrying loads of lumber.
More Traffic Information
This eastbound overloaded Type 10 traffic pattern is quite different from the
westbound pattern.
Detecting
such patterns and directional differences would take hours of analysis using the
sensor vendor’s reporting software and traditional graphics programs. JOHO
makes them visible immediately with no additional labor after automated image
generation.
JOHO also provides computational capabilities to further manipulate
images. From this image, and a similar one showing all Type 10 trucks, we
calculated the percentage of overweight trucks. That image would be very
useful in enforcement applications.
This site also contains FHWA Type 11 images and
total vehicle
count images that show other examples of how the Maine DOT is using JOHO
to monitor their sensors and to understand traffic patterns throughout the
state.
