|(a) Authority to set variable speed limits. House Bill
2204, 83rd Legislature, Regular Session, 2013, requires the commission
to establish, and the department to implement, a variable speed limit
pilot program to study the effectiveness of temporarily lowering prima
facie speed limits to address inclement weather, congestion, road
construction, or any other condition that affects the safe and orderly
movement of traffic on a roadway. The executive director of the department
will select the areas of the state in which the pilot program will
be conducted. The department's district engineers in the selected
areas are responsible for establishing the reduced speed limits for
the affected roadways and the periods of effectiveness based on the
criteria provided in this section. A district engineer may delegate
that authority to the districts' deputy district engineer, director
of construction, director of operations, or director of maintenance,
or a director of transportation operations or a traffic engineer for
(b) Criteria for variable speed limits. The established
prima facie speed limits on a portion of the state highway system
may be lowered as necessary for the safe and orderly movement of traffic
as a result of traffic volume, adverse weather conditions, highway
construction work zones, or traffic crashes and incidents. These reduced
speed limits must be based on an engineering and traffic investigation
and will be lowered only in multiples of five miles per hour.
(c) Engineering and traffic study. The engineering
and traffic study required to establish the variable speed limit may
include the determination of a spot speed within the affected area,
speed-over-distance readings from automated field technology, sight
distance during inclement weather, or traffic flow obtained by either
field investigation or automated technology. An 85th percentile speed
study is not required for establishing a variable speed limit.
(d) Sign placement. A speed limit established under
this section is effective only when a sign indicating the change in
the speed limit is displayed between 500 and 1,000 feet before the
point at which the speed limit takes effect. A sign will also be posted
at the point where the speed limit takes effect. The department may
use an electronic sign that is capable of displaying more than one
message for posting a reduced speed limit.
(e) Documentation of lowered variable speed limits.
The department will keep an official record of all changes made to
prima facie speed limit established for an affected roadway that includes
the date, time, and duration of the lowered speed limit.
(f) Coordination. The department will coordinate closely
with state and local law enforcement agencies regarding the locations
and reduced speed limits at all variable speed limit sites. The department
will make records maintained under subsection (e) of this section
available to state and local law enforcement entities in order to
support speed limit enforcement.
(g) Expiration. This section expires February 1, 2015.