HomeMy WebLinkAboutA001 - Council Action Form dated October 8, 1991 COUNCIL ACTION FORM
Item #
Date: Octo er , 1991
SUBJECT: Establishing a speed limit on Mortensen Road
BACKGROUND:
Mortensen Road is a joint jurisdictional roadway with the City and County
responsible for the signing, pavement marking, street maintenance, and
snow removal. During the past month, Story County and Iowa State
University designated a 40 mph speed limit on a portion of Mortensen Road
from State to South Dakota. Currently, no official speed limit is designat-
ed for the west 1,315 foot section of Mortensen Road under the City's
jurisdiction.
Staff performed an evaluation and concluded that a 40 mile per hour speed
limit should be posted on the roadway. Roadway conditions, motorists
speeds, speed limits on similar arterial roadways, and other criteria were
used to determine this speed limit. All factors indicated that the most
appropriate speed limit was 40 mph.
Since the roadway is paved and a through route, a speed limit of 40 mph
would be appropriate according to the Iowa Code because it is a suburban
roadway. Staff conducted a speed study which showed that 85% of the
motorists were driving at speeds lower than 42 mph. Traffic engineering
guides recommend that speed limits should be posted at speeds that 85% of
the motorists were traveling. According to studies, 85% of the motorists
travel at or below speeds that are safe for the prevailing roadway condi-
tions. With speed limits established at this speed, overall compliance
would be achieved and safety would be enhanced by decreasing conflicts
between faster and slower drivers.
Also, taken into consideration for determining the speed limit was the
limited number of accesses, roadway conditions, and the speed limits
established on similar arterial roadways. Speed limits designated on other
arterial roadways adjacent to Mortensen Road have either posted 1140 mph"
or "45 mph" speed limits. Roadways with this speed limit include State
Avenue, South Dakota, and Airport Road. Motorists would safely travel
Mortensen at 40 mph since it has slight grade and roadway curves, few
street intersections, and residential accesses along the route.
ALTERNATIVES:
1. Designate a 1140 mile per hour" speed limit on Mortensen Road on the
City's portion extending east 1,315 feet from South Dakota.
2. Designate another speed limit on Mortensen Road.
CAF - Speed Mortensen Rd.
October 8, 1991
Page 2
3. Do nothing.
MANAGER'S RECOMMENDED ACTION:
It is recommended by the City Manager that the City Council adopt alter-
native number 1 above, thereby designating a 1140 mile per hour" speed
limit on Mortensen Road on the City's portion extending east 1,315 feet
from South Dakota.
COUNCIL ACTION
SL:Revl