¥1993 - Institute of
Transportation Engineers (ITE):
" Speed Zone
Guidelines - A Recommended Practice
"
¥"3. Rationale for
Consistent Speed Zone Guidelines - .... A third rationale is the need for consistency between the speed limit and other traffic control devices. Signal timing and sight distance requirements, for example, should be based on the prevailing speed of traffic. If these values are based on a speed limit that does not reflect the prevailing speed of
traffic, safety might be compromised." ........
"
" "4.
Recommended Practice - .... It is recommended that the engineering study include an analysis of the current speed distribution of free-flowing vehicles. It is further recommended that the speed limit within speed zone be
set at the nearest 5 mph increment to the 85th
percentile speed or the upper limit of
the 10 mph pace."