Resolution 2008-086
RESOLUTION NO. 2008 _ 86
A RESOLUTION OF THE BOARD OF COUNTY COMMISSIONERS OF COLLIER
COUNTY, FLORIDA, AUTHORIZING A SPEED LIMIT REDUCTION FROM FORTY-
FIVE MILES PER HOUR (45 MPH) TO FORTY MILES PER HOUR (40 MPH) ON
NORTHBROOKE DRIVE FOR THE SECTION 200 FEET NORTH OF MILLCREEK
LANE NORTH TO ITS TERMINUS AT QUAIL WEST DEVELOPMENT.
WHEREAS, Chapter 316, Florida Statutes, permits the Board of County
Commissioners (BCC) to alter established speed limits on roads under its jurisdiction;
and
WHEREAS, NORTH BROOKE DRIVE falls under the jurisdiction of the BCC; and
WHEREAS, in accordance with Section 316, Florida Statutes, the BCC may alter
such existing speed limits as may be appropriate upon the basis of an engineering and
traffic investigation; and
WHEREAS, the results of such engineering and traffic investigations determined
that the reduced speed limit is reasonable and safer under the conditions found to exist
and it conforms to criteria promulgated by the Florida Department of Transportation and
Collier County.
NOW, THEREFORE, BE IT RESOLVED BY THE BOARD OF COUNTY
COMMISSIONERS OF COLLIER COUNTY, FLORIDA, that:
1. The BCC does hereby establish a 40 miles per hour (40 mph) speed limit on
Northbrooke Drive from the section 200 feet north of Millcreek Lane north to its terminus
at Quail West development, a distance of 1.6 miles, and does hereby direct the County
Traffic Operations Department to erect appropriate speed limit signs giving notice
thereof.
2. A copy of this Resolution be forwarded to the Collier County Sheriff's Office for
proper enforcement of the established speed limits for Northbrooke Drive within the
designated segments.
3. The effective date of the speed limit reduction shall be after written notification to
the Sheriff's Office and upon posting of the appropriate signage.
This resolution adopted after motion, second, and majority vote favoring same
this 8th day of April, 2008.
ATTEST: BOARD OF COUNTY COMMISSIONERS,
DWIGHT E. BROCK, Clerk , COLLlER~NTY, F. RIDA..
~ tk4fLt k-?BY: :JfJl-'
Deputy Clerk Tom Henning, Chairman
Attest as to ChaIrman s
::~~ ~ tB%~2~egal sufficiency
Scott R. Teach,
Managing Assistant County Attorney
Speed Limit Study Report
Northbrooke Drive
Date: 3/07/08
By
Eugene Calvert, PE, PTOE
BACKGROUND
The Collier County Traffic Operations Department has conducted an engineering and
traffic investigation study to determine the appropriate speed limit along Northbrooke
Drive from Immokalee Road, north to its terminus at Quail West Development.
Northbrooke Drive is a 2.0 mile roadway functionally classified as a local road. The
roadway is located east of 1-75 and north of Immokalee Road; and provides access to
numerous gated - golf course communities.
The primary intent in the establishment of a speed zone is to provide improved vehicular
and pedestrian safety by reducing the probability and severity of crashes. An established
speed limit notifies the driver ofthe maximum and/or minimum speed that is considered
acceptably safe for optimum weather and visibility. It is intended to establish the
standard or speed limit which the normally prudent driver can react more safely to
driving problems encountered on the roadway.
DESIGN CHARACTERISTICS
Northbrooke Drive is a two-lane, two-way roadway with II foot wide travel lanes and no
paved shoulders. The roadway cross section is typically a rural section with no curb and
gutter. The centerline is typically marked with a normal broken yellow line and the edge
ofthe travel way has white edge line markings. Except at a few of the intersections,
passing is permitted throughout the length of the roadway.
The first 700+ feet of the road north of Livingston Road provides access to various
commercial establishments in the Northbrooke Plaza. At approximate mile post (M.P.)
0.14 the road intersects with the terminus of Oakes Boulevard. Traffic control at this
intersection is provided with a stop control for northbound Northbrooke Drive.
Northbrooke Drive continues to the north providing access to fourteen (14) local streets
and/or driveways. There are five (5) marked cross walks/golf cart crossings along the
length of the roadway.
The current posted speed limit for the roadway is:
M.P. 0.0 @ Livingston Road intersection to M.P. 0.4 = 35 mph
M.P. 0.4 to M.P. 2.0 ~ 45 mph
There are four (4) horizontal curves along the alignment that have proper advanced
warning signs with 35 mph advisory speed plates. Passing is currently permitted along
the majority of the roadway, even through the 35 mph horizontal curves.
Advance warning signs are provided for some, but not all of the golf cart crossings. The
warning signs are not in compliance with the Manual on Uniform Traffic Control
Devices (MUTCD) in regards to advance placement distance or retroretlectivity. The
crossing are delineated by crosswalk pavement markings. In addition, the crosswalk
pavernent markings are becoming worn and need to be repainted.
SPEED INVESTIGATION
Florida Statutes require that the change of speed zone values as outlined in Sections
316.183 and 316.189 F .S. be based upon an engineering and traffic investigation. The
investigation is to include, but is not limited to, the measurements of prevailing speeds
and other traffic engineering evaluations contained in the "Speed Zoning for Highways,
Roads and Streets in Florida" manual (FDOT Manual Number 750-010-002,1997
Edition). This manual was developed by the Florida Department of Transportation to
promote uniformity in the establishment of state, municipal and county speed zones
throughout the State of Florida.
Three types of data were utilized in determining the prevailing speed: 85th percentile
speed, upper limit of the 10-mph pace and average test run speed. The reasoning behind
the foregoing investigations is that the majority of drivers travel at reasonably safe speed
for the various roadway conditions encountered, and that these investigations help
determine what may be reasonable speed limits.
Prevailing vehicle speeds were measured during free-flow traffic conditions on Tuesday
February 26, 2008 from 9:30 am to II :30 am on a straight and open segment of the road
where the current speed limit is posted at 45 mph. The following data was collected:
85th percentile speed - northbound = 41 mph
85th percentile speed - southbound = 43 mph
I O-mph pace - northbound = 31 mph - 41 mph
I O-mph pace - southbound = 32 mph - 42 mph
Field test run speed = 40 mph
ANALYSIS
Unless safety issues exist along the roadway that are not readily apparent to the driver, a
speed limit should not typically differ from the 85th percentile speed or upper limit of the
I O-mph pace by more than 3 mph and it should not be less than 8 mph. The measured
85th percentile speed of 41 mph to 43 mph and the 10-mph pace would support a 40 mph
speed limit.
The four horizontal curves along the length of the roadway, the various streets and/or
driveway intersections, and the crosswalks/golf cart crossings further support that the
existing speed limit be lowered to 40 mph.
The passing sight distances on Northbrooke Drive are generally not adequate to support
the established passing zones except between approximate M.P. 1.0 and M.P. 1.5. The
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MUTCD requires that a minimum of 600 feet of passing sight distance be available when
the posted speed limit is 40 mph. Between M.P. 1.0 and M.P. 1.5 there are four
intersecting roadways with Northbrooke Drive. While the sight distance may meet the
required minimum, the intersections cause a conflict with vehicles that desire to pass with
vehicles turning on to and off of Northbrooke Drive. For consistent driver expectations,
consideration should be given to restrict passing over the entire length ofNorthbrooke
Drive.
RECOMMENDATION
I. Based upon the speed investigation of the Northbrooke Drive and the various
approaches onto the roadway, it is recommended that the current 45 mph speed limit on
Northbrooke Drive from M.P. 0.4 to M.P. 2.0 be reduced to 40 mph.
2. It is recommended that two-direction no-passing pavement markings be installed over
the entire length of the roadway.
3. The advance warning golf cart crossing signs be replaced with proper signage and the
crosswalk pavement markings be remarked.
F:\Traffic Operations\Traffic Sludies\Speed Limit Studies\Northbrooke Drive\1008 Northbrooke Dr -Immokalee to
end\Report\Northbrooke Drive Speed Zone Study 03-07-08.doc
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