LESSON 1/TASK 1
study team to collect information that reflects normal driving behavior. Obvious MP presence, as well
as unusual weather conditions, will cause drivers to behave in a manner other than normal.
The period in which the study is to be conducted is usually broken up into three time periods. Under
normal circumstances these time periods are 0900-1200, 1500-1800, and 2000-2200. A period of at
least one hour is selected within each of these three for each location under study. During the hour
selected, there should be at least 50 vehicles passing the location. Speeds of the vehicles are checked
on a controlled basis. For example, the speed of every second vehicle is checked. This can be varied,
depending on the volume of traffic. Enough vehicles must be checked to provide valid data.
Locations
The location selected for a speed study will depend on the reasons for conducting the study. Some of
the types of locations that may be selected for speed studies include:
o Roadways which have recently had the speed limit changed.
o Places where there is a need to evaluate existing speed limits.
o Locations for which traffic control devices have been proposed.
o All major thoroughfares.
o Locations with a high frequency of traffic accidents.
Locations which normally require a reduction in speed are not studied unless specifically desired. They
do not provide information on normal driving speeds.
The location selected for a speed study should not normally be one in which a recent speed
enforcement campaign has been conducted. Just as obvious MP presence or adverse weather
conditions will affect a driver's habits, so will the results of such a campaign. The data gathered will
not, therefore, reflect the normal habits of the vehicle operators.
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