HomeMy WebLinkAbout2017-05-15-J03 Speed Limit Ordinance_SE Westown Pkwy_INTRO, 1ST READ1, ►4 Waukee
1'I / THE KEY 7O GOOD LIVING
AGENDA ITEM:
CITY OF WAUKEE, IOWA
CITY COUNCIL MEETING COMMUNICATION
MEETING DATE: April 17, 2017
AGENDA ITEM: Consideration of approval of an ordinance to amend Chapter 501, Waukee
Municipal Code, Regarding the speed limit on SE Westown Parkway within
the City Limits of the City of Waukee, Iowa [introduction; first, second, third
(final) readings]
FORMAT: Ordinance
SYNOPSIS INCLUDING PRO & CON: The Speed Justification completed November 10, 2015
recommends the posted speed limit in the existing school zone corridor
remain at 25 mph and the minor arterial SE Westown Parkway corridor east of
SE Parkview Crossing Drive be posted at 35 mph.
FISCAL IMPACT INCLUDING COSTBENEFIT ANALYSIS:
COMMISSION/BOARD/COMMITTEE COMMENT:
STAFF REVIEW AND COMMENT:
RECOMMENDATION: Approve the ordinance.
ATTACHMENTS: I. Proposed Ordinance
PREPARED BY: Beth Richardson
REVIEWED BY: John Gibson
PUBLIC NOTICE INFORMATION —
NAME OF PUBLICATION:
DATE OF PUBLICATION:
ORDINANCE NO. 17-
AN ORDINANCE TO AMEND CHAPTER 501, WAUKEE MUNICIPAL CODE,
REGARDING THE SPEED LIMIT ON SE WESTOWN PARKWAY WITHIN THE
CITY LIMITS OF THE CITY OF WAUKEE, IOWA.
WHEREAS, the City of Waukee has determined through a traffic study that a new speed
limit shall be implemented on certain portions of SE Westown Parkway within the City of Waukee.
BE IT THEREFORE ORDAINED by the City Council of the City of Waukee:
Section 1: Chapter 501, Waukee Municipal Code, Regulation of Traffic Upon and Use
of the StrWaukee, Iowa, is hereby amended by adding Section 501.9(F)(17) as follows:
§5019(F)(17) The speed limit on SE Westown Parkway between SE LA Grant Parkway
and Grand Prairie Parkway shall be 35 miles per hour.
Section 2 Repealer. All ordinances or parts of ordinances in conflict with the provisions
of this ordinance are hereby repealed.
Section 3. Severability Clause. If any section, provision or part of this ordinance shall
be adjudged invalid or unconstitutional, such adjudication shall not affect the validity of the
ordinance as a whole or any section, provisions or part thereof not adjudged invalid or
unconstitutional.
Section 4. Effective Date. This ordinance shall be in effect from and after its final
passage, approval and publication as provided by law.
Passed by the Council the day of , 2017, and approved this day of
, 2017.
Attest:
Rebecca D. Schuett, City Clerk
William F. Peard, Mayor
1
+Foth
November 10, 2015
TO: John Gibson, Public Works Director
CC: Josh DeBower, PE
FR: Molly Long, PE, Steven Younkin
RE: Speed Justification
SE Westown Parkway Extension
Project No.: 14W021.02
8191 Birchwood Ct, Suite L
Johnston, Iowa50131
(515)254-1393 • Fax: (515) 254-1642
www.foth.com
Memorandum
Introduction
The purpose of this memo is to justify the posted speed limit along existing and proposed SE
Westown Parkway between SE LA Grant Parkway and Grand Prairie Parkway. Several factors
will be considered to justify the chosen speed including roadway geometry, horizontal
obstructions, land -use and neighboring speed limits.
Speed Justification Location
The total length of the study area is 0.75 miles along SE Westown Parkway between SE LA
Grant Parkway and Grand Prairie Parkway. The roadway classification according to the city of
Waukee is minor arterial_
The existing SE Westown Parkway has
separate characteristics from the proposed
area. Existing Westown has a posted speed
limit at 25 mph. The area is in an urban
setting with primarily residential land use
and property lines offsets from the traveled
way of the road at least 30 ft. It is a two-lane
undivided road cross-section with no
horizontal curvature and little vertical
curvature. Driveway density is low with
housing access coming solely through local
roads. Additionally there is South Middle
School at the west end with a drive accessing
Westown.
The property adjoining proposed SE
Westown Parkway is primarily zoned
commercial. The proposed area has a fully implemented access management plan for the
commercial driveways. Roadway geometry remains flat and straight.
Speed Justification Literature
NCHRP report 5011 recommends speeds for streets to be between 30 to 45 mph in the minor
arterial functional class.
Memo RE: SE Westown Speed Justification
November 10, 2015
TABLE39 Typical dinfensions for urban (and suburban) classes
Clasa�labfln4%:
`YPINBY
Arle'iilt
Cnlitetnra
I.Ueal
Item
Principal
Nlnmr
(Nnun•Ptua)i
Aiinapmed Speed or
i5 m70
45 m55
30 to 45
35 m45
s30
Speed limit bnphl
Many organizations use the 85t1' percentile speed of traffic as an indication of the appropriate
speed limit. The 851h percentile speed is the velocity at which 85% of vehicles are traveling at or
under. With the absence of speed data, a regression equation can be used which was developed
by Fitzpatrick et. al Z. This regression equation was calibrated specifically for Suburban/Urban
Arterials and takes the form of:
EV85 = 8.66 + .963 * (Posted Speed Limit)
With the 35 mph posted speed limit this predicts that the 85`h percentile speed will be 42 mph.
Recommendation
The presence of a school zone in the existing area recommends speed zones to not be raised in
the vicinity of the school. Streets with residential land use nearby typically have a 25mph posted
speed limit regardless, so it is recommended the existing roadway remain at the 25mph posted
speed limit.
The proposed corridor's classification as a minor arterial lends itself to not have speeds below 30
mph. The lack of road curvature, 30ft minimum distance from lateral obstructions, and
commercial zoning also suggests that a posted speed limit below 30mph would not be
appropriate. It is important for drivers to not have a large speed change from zone to zone. The
existing roadway has a speed limit of 25mph. Due to lack of length for a vehicle speed transition
and the previously mentioned factors the recommendation is to set the proposed corridor speed
limit at 35 mph.
The recommendation given is setting the speed limit at 35mph in the proposed corridor and leave
existing corridor speed at 25mph. This solution accommodates the mixture of roadway factors
and driver expectancy most effectively.
Appendix
1. Fitzpatrick, Kay, Paul Carlson, Marcus Brewer, and Mark Woolridge, Shaw -Pin Miaou. "NCHRP Report 504"
Transportation Research Board (2003). Web. 3 Nov. 2015.
2. Fitzpatrick, Kay, Paul Carlson, Marcus Brewer, and Mark Woolridge. 'Design Speed, Operating Speed, and
Posted Speed Limit Practices." Transportation Research Board (2003). Web. 3 Nov. 2015.