Agenda 01/05/2004 W Agenda
Naples City Council
Board of County Commissioners, Collier County
City Council Chamber, 735 Eighth Street South, Naples, Florida
Joint Meeting
Monday, January 5, 2004
1:30 p.m.
All proposed ordinances and information on other items listed below, which have been provided in
advance of this meeting, may be inspected in the office of the City Clerk, Room B, City Hall, or at the
Collier County Public Library Research Section, 650 Central Avenue. See also City of Naples home
page http://www.naplesgov.com or call the City Clerk's Office, 213-1015. All written, audio-visual
and other materials presented to the City Council in conjunction with deliberations during this
meeting will become the property of the City of Naples and will be retained by the City Clerk.
1. Roll call
2. Invocation and Pledge of Allegiance
3. Set Agenda (add or remove items)
4. Discussion of Transportation Issues
a. Overpass Feasibility Alternative Solutions
b. Proposed 2nd Gordon River Bridge
c. U.S. 41 By-Pass
d. Waterside Shops Expansion and Other Commercial Ventures
5. Heart of Naples Comprehensive Plan Amendment
6. Ruffina Annexation
7. Public Comment
8. Adjourn
NOTICE
Formal action may be taken on any item discussed or added to this agenda. Any person who decides to appeal any
decision made by the City Council with respect to any matter considered at this meeting (or hearing) will need a
record of the proceedings and may need to ensure that a verbatim record of the proceeding is made, which record
includes the testimony and evidence upon which the appeal is to be heard. Any person with a disability requiring
auxiliary aids and services for this meeting may call the City Clerk's Office at 213-1015 with requests at least two
business days before the meeting date.
Agenda Item #4 - Transportation Issues
Attached is a copy of a memo from Naples Public Works Director, Dan Mercer. Therein,
Mr. Mercer summarizes the "Final Report" prepared by Parsons Brinckerhoff Quade &
Douglas, Inc. (PB) who prepared the report for the Collier County Transportation
Department. A copy of the PB report is also attached.
The PB report provides a preliminary analysis of the Golden Gate Parkway / Airport
Pulling Road intersection, including an examination of 'unconventional' intersection
designs for that location. In their report, alternatives in lieu of an overpass, are available
for County consideration.
Also attached is a copy of an Executive Summary prepared by County staff which
provides data and analysis regarding the various improvements to the Airport-Pulling
Road / Golden Gate Parkway intersection.
At the January 5, 2004 Workshop, a City staff presentation will be made to address traffic
concerns that directly and indirectly effect this overpass issue. A presentation from
County staff is also anticipated.
Agenda Items #5 and #6
No City or County staff presentations have been prepared for either of these items.
Arrangements are currently being made for a joint meeting between City and County
staff members to discuss an interlocal agreement on the Ruffina annexation.
Engineering · Utilities · Solid Waste · Equipment Services
TO:
FROM:
DR. ROBERT E. LEE, CITY MANAGER
DAN MERCER, PUBLIC WORKS DIRECTOR
SUBJECT:
FINAL REPORT-PRELIMiNARY EVALUATION OF UNCONVENTIONAL
INTERSECTION DESIGNS/GOLDEN GATE PARKWAY/AIRPORT-PULLING
ROAD INTERSECTION
DATE:
DECEMBER 30, 2003
As you are aware the City has recently received a copy of the 'Final Report' on
the Golden Gate Parkway/Airpod-Pulling Road Intersection. Parsons Brinckerhoff
Quade & Douglas, Inc. (PB) submitted the report dated December 8, 2003, to
Collier County Transportation Department. Previously the City Council had
received a copy of the 'Draft Report' dated November 13, 2003. In reviewing
both copies t find very minor and insignificant changes between the content of
the documents. Some of the changes consisted of sentence structure, grammar
revisions, and expansion of information. Table 3 was revised in structure only to
be easier to read, but the data it contained remained the same. In Exhibit 'A' a
couple of figures were relocated for better understanding. In Exhibit 'A' of the
Final Report, figure 3 the footprint changed somewhat.
This study of unconventional intersections designs was initiated by a presentation
to the City. The presentation along with a letter from PB made its way to Collier
County. In a good faith effort Collier County decided to hire PB to produce the
study. PB was then asked to perform a preliminary analysis of the Golden Gate
Parkway/Airport-Pulling Road intersection, including an examination of
"unconventional" intersection designs for that location. Typical unconventional
designs include Roundabouts, Median U-turns, Jughandles, and newer concepts
such as Continuous Flow Intersections, Quadrant Roadways, and Split
Intersections. PB also looked into other unconventional grade-separated
designs such as the Echelon and the Center Turn Overpass. tn their report PB
mentions that early on they quickly eliminated several concepts, such as:
Roundabout-type treatments, Continuous Flow intersection, Quadrant Roadway
intersections, Echelon and Center Turn Overpass interchange concepts. Then PB
PAGE 2
FINAL REPORT-PRELIMINARY EVALUATION OF UNCONVENTIONAL INTERSECTION
DESIGNS/GOLDEN GATE PARKWAY/AIRPORT-PULLING ROAD INTERSECTION
DECEMBER 30, 2003
selected several unconventional layouts, including the Median U-turn, Split
Intersection and Continuous Flow Intersection. I am not sure if it was an error or
typo, but they had mentioned earlier the elimination of the Continuous Flow
Intersection, so I am not sure whether they analyzed it or not?
Again, let me mention this report is_extremely preliminary and actually produces
more questions than answers. Just as PB recommends, a more intensive Corridor
Congestions Management Study is both appropriate and essential. A study such
as this would provide a basis for strengthening the comprehensive and
integrated investment strategy for the entire Corridor.
In conjunction with this report, staff reviewed Collier County's 2002 Average
Daily Traffic report. In April 1989, Collier County Transportation Department took
over all traffic counting activities on State roads (except for 1-75) and County
roads in unincorporated coastal Collier County. These counts are taken to
measure seasonal variations and to identify growth patterns. The 2002 report
indicates an overall County wide average increase of 0.4.7%. PB developed a
set of projections using an average growth rate of two percent (2%) per year for
existing counts performed in 2000 to be used over the next 20 years. Table 2 of
PB Final Report shows the calculations produced by Kimley-Horn and Associates
dated January 3, 2003, and the new calculations produced by PB using the 2%
growth. By using the 2% there is a significant difference in the two projections,
particularly in regard to their conclusions as to the need for an overpass in the
distant future. I am sure PB may have a logical explanation as to why they used
2%, but staff has not been able to reach them for an answer. Of concern is both
the inconsistency in data and in recommendations.
Another important piece of the puzzle was found in the County's 2002 Average
Daily Traffic report that I think warrants plugging into the plan. That is a
significant change in the traffic counts since the construction of Livingston Road
extension from Radio Road to Pine Ridge Road. Traffic seems to have migrated
south toward Radio Road, to Airport Road, and then to Davis, etc. Staff would
have expected an increase in traffic from Livingston Road then west on Golden
Gate Parkway into the City. The latest counts do not show that. This would
leave me to believe if a new corridor was added south of Golden Gate
Parkway (maybe a 2nd Gordon River Bridge) that the need for major
improvements at Golden Gate Parkway and Airport-Pulling Road might not be
warranted! I am not saying no improvements are needed at this intersection,
but the thought of spending $10 - $15,000,000 versus $30,000,000 sound much
PAGE 3
FINAL REPORT-PRELIMINARY EVALUATION OF UNCONVENTIONAL INTERSECTION
DESIGNS/GOLDEN GATE PARKWAY/AIRPORT-PULLING ROAD INTERSECTION
DECEMBER 30, 2003
more appealing. The remaining $15,000,000 could be used elsewhere to
improve traffic flow throughout the County road system.
The most notable information I have been able to gather from the Final Report
provided by PB is there are numerous other alternatives that are available in lieu
of an overpass configuration at thi~ time. The alternatives involve intersection
configurations and other corridor improvements, as indicated by our on-going
review of the data. In the interest of obtaining the most 'capacity' for the
'dollar', I do think there are solutions to improving the road network that
potentially create more capacity (concerns the City and the County faces), but
further studies are necessary fo justify this.
Staff is in the process of completing a 'draft' presentation to address traffic
concerns in general to be presented at the City-County Workshop on Monday,
January 5, 2003. It will include information from this Final Report and the 2002
Average Daily Traffic data from the County that will look at most of the issues we
face currently, such as the Overpass, Waterside Shops expansion, and others. I
hope to have the draft to you by Wednesday afternoon for review and
finalization.
If you require any additional information please contact me. Thank you.
FINAL REPORT
Preliminary Evaluation of Unconventional
Intersection Designs
Golden Gate Parkway/AirpOrt-Pulling Road
Intersection
Collier County, Florida
Submitted to:
Collier County Transportation Department
By:
Parsons Brinckerhoff Quade & Douglas, Inc.
December 8, 2003
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road intersection
Collier County, Florid~
1.0 Introduction
Parsons Brinckerhoff Quade & Douglas, Inc. {PB) was asked to perform a preliminary analysis of
the Golden Gate Parkway/Airport-Pulling Road intersection, including an examination of
"unconventionaF intersection designs for that location. The intersection is proposed to be grade-
separated due to projected growth in the area as well as traffic volumes associated with the new
1-75 interchange with Golden Gate Parkway. 1-75 is located approximately two miles west of the
intersection under study.
PB has extensively researched into howother state, county and local transportation agencies
handle high-volume intersections; thus the firm is uniquely qualified to evaluate feasibility,
planning and design issues associated with various "unconventional" intersection solutions.
On November 5 and 6, 2003, the PB Team joined with Post Buckley Schuh & Jernigan, Inc.
(PBS&J) representatives and Collier County Transportation officials in a work session to review
potential unconventional intersection designs at the intersection of Golden Gate Parkway and
Airport-Pulling Road as well as at other locations along the Golden Gate Parkway corridor,
including Santa Barbara Boulevard. County officials had provided existing information, studies
and plans to the pB Team in advance of the work session to ensure a consistent framework for
considering alternatives.
2.0 Golden Gate and Airport-Pulling Intersection
2.1 Unconventional Intersection Design Concepts
When conventional intersection design concepts do not to provide adequate existing or future
capacity, many communities are looking for "unconventional" design solutions - concepts that
reduce the impact of left turning traffic volumes at the intersection and share common principles
of separating left turn movements through various designs. Typical unconventional designs
include Roundabouts, Median U-turns, Jughandles, and newer concepts such as Continuous
Flow Intersections, Quadrant Roadways, and Split Intersections. Unconventional grade-
separated designs such as the Echelon and the Center Turn Overpass also were discussed.
Early in the session, several concepts were quickly eliminated:
· Roundabout-type treatments could not handle the magnitude of volumes at this intersection
and were felt to have significant motorist acceptance issues in this area
· The Continuous Flow intersection and Quadrant Roadway intersections could not be fit within
the available right-of-way footprint without significant additional takings, property and access
impacts and drainage basin mitigation.
· The Echelon and CenterTurn Overpass interchange concepts are unlikely to provide
significant cost savings or operational benefits compared to the planned interchange design.
2.2 Comparison of Initial Intersection Layouts
Several unconventional layouts were selected for further study, including the Median U-turn, Split
Intersection and Continuous Flow Intersection. These designs were analyzed using simulation
models to compare traffic impacts compared to a conventional intersection design and the single-
point overpass design currently planned.
Page I oi 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, Florida
-Fable I summarizes the initial results for the 2025 design year according to volume-to-capacity
ratios. The volume-to-capacity (v/c) ratio is the measure of how much of the available capacity of
an intersection is being used. A volume to capacity ratio of 1.42 for example means that the
intersection is over the available capacity by 42 percent. The higher the v/c ratio, the greater the
delay (amount of time a driver has to wait) at an intersection. A v/c ratio slightly greater than 1.0
typically means that drivers will experience moderate delay and have to wait a minimum of one
signal cycle before clearing the intersection. Higher v/c ratios also indicate a greater length of the
peak hour, lasting until volumes recede to a v/c ratio of less than 1.0 and the intersection can
begin to clear. Intersections with v/c ratio~ under but near 1.0 may still have some peak queuing
and delays, and intersections with v/c <0.80 will generally operate without undue delays. Table 1
reports v/c ratios for the worst intersection within the study limits, because many of the
unconventional designs create multiple signalized intersections of varying operations.
Table 1: Initial 2025 Volume-to-Capacity Analysis Results
Intersection Design 2025 PM VIC
Conventional Intersection 1.42
Single POint Overpass (planned) 0.85
Median U-Turn (crossovers only on Golden Gate Parkway) 1.21
Continuous Flow Intersection 1.05
Split Intersection (with median crossovers) 1.11
Echelon Interchange 0.98
Only the interchange designs (Single Point Overpass and Echelon Interchange) could provide
sufficient peak hour capacity at the intersection, although several of the unconventional designs
provide improved efficiency compared to the conventional design at near capacity operations in
2025. These unconventional at-grade alternatives could be implemented at substantial cost
savings compared to an interchange design.
2.3 Preliminary Intersection Layout
During the work session, a Split Intersection (with median crossovers) design concept was
developed and considered for further analysis. The layout consisted of routing the northbound
and southbound left turns on Airport-Pulling Road to two signalized median U-turns on Golden
Gate Parkway east and west of Airport-Pulling Road. Both arterials would retain the proposed
six-lane typical section. The intersection of Golden Gate Parkway and Airport-Pulling Road would
be "split", with separate signalized intersections provided for eastbound and westbound
movements. Left turns from Golden Gate Parkway to Airport-Pulling Road would be provided at
these intersections. This layout was analyzed further because it could fit within the proposed
right-of-way for the planned overpass, could be built as the first phase of the overpass, and could
be retrofitted to the ultimate proposed design of the overpass without major reconstruction.
Further, refinements to the ultimate interchange design can be made to minimize "wasted" costs
and provide a more cost effective transition between phases.
Further details on the history and background of this type of intersection as well as its applicability
to the location under study are provided in Exhibit A.
Page 2 of 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airpoa-PuIling Road Intersection
Collier County, Florida
2.4 Traffic Projections
The traffic simulation for the Split Intersection (with median crossovers) alternative on Golden
Gate Parkway and Airport-Pulling Road was performed using two sets of traffic projections. The
traffic volumes are provided in Exhibit B.
The first set was provided by Collier County staff and is documented in the traffic study performed
by Kimley-Horn and Associates (KH&A) dated January 3, 2003. Decreases between existing
(2000) counts and the projected traffic on northbound and southbound Airport-Pulling Road can
be attributed to changes in travel patterns-as a result of the proposed new interchange at Golden
Gate Parkway and 1-75.
The second set of projections was developed using an average growth rate of two percent per
year from existing counts performed in 2000. This average growth rate was developed by
comparing average annual daily traffic volumes between 1998 and 2002. These volumes,
provided by Collier County staff, show an average growth of less than two percent per year along
both arterials under study. However, a two percent growth was assumed to account for traffic
reductions due to roadway construction in the area between 1998 and 2002. Approach volumes
to the intersection were developed by applying the two percent yearly growth rate to existing
approach counts. In order to account for the new interchange at Golden Gate Parkway, the
turning movements were calculated using the trip distribution from the data developed by KH&A.
This methodology resulted in an increase in volumes for all of the movements at Golden Gate
Parkway and Airport-Pulling Road, except for Golden Gate Parkway westbound.
The following table shows the existing counts as well as the two sets of projections used for the
analysis.
Table 2: Traffic Projections
Existing 2005 PM Peak Volumes 2025 PM Peak Volumes
Volumes Estimated (2% Estimated (2%
Approach (PM 2000) KH&A Annual Growth) KH&A Annual Growth)
Golden Gate Pkwy 850 940 945 1,520 1,290
_~_e s t___b2_u_Qn d__ .............................................................................................................................................
Golden Gate Parkway 2,720 2,910 2,990 3,350 4,075
_ E_._a s t__b_o..u. _n._d ..............................................................................................
Airport-Pulling Road
3,270 2,700 3,600 2,750 4,910
._N_o.~.b_b_o_ u_~.~ ................................................................................................
Airport-Pulling Road
2,015 2,510 2,215 2,510 3,020
Southbound
Note:
Volumes are in vehicles per hour per direction.
2.5 Roadway Network
The proposed roadway network is shown in Exhibit C. The left turns from Airport-Pulling Road
both northbound and southbound are projected to be heavier than the left turns from Golden Gate
Parkway. With the proposed layout, left turns from Airport-Pulling Road will first turn right at
Golden Gate Parkway and than use the median U-turns to continue east and west on Golden
Gate.
Page 3 of 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, Florida
The analysis is based on the median U-Turns located approximately 600 feet east and west of
Airport-Pulling Road, and a distance of approximately 150 feet between the Golden Gate
intersections with Airport-Pulling Road. This design seems to fit within the available right-of-way
along both arterials, while allowing full intersection movement at Bear's Paw (approximately 2,600
feet from Airport-Pulling Road) to the west. Right-in/right-out driveways can also be built into this
design to allow access to future residential sites at the northwest corner of the intersection and
the Gray Oaks future commercial site in the northeast quadrant of the intersection.
The median crossover east of 'Airport-Rulling Road will allow left-in access to the Poinciana
Professional Park, and right-turn out movements can take place with the crossover movements.
This maneuver does not seem to create operational and/or safety issues as the number of
vehicles performing that turn is projected to be less than 50 vehicles per hour during the
afternoon peak period in 2025. This condition also exists in the westbound direction of traffic
from the Gray Oaks future commercial site located at the northwest quadrant of the intersection.
Similarly, volumes exiting the site and heading south to Airport-Pulling Road are projected to be
minimal and significantly impact intersection traffic operation and safety. In both cases, the
heavier flow of traffic, eastbound and westbound on Golden Gate Parkway, will be metered by the
traffic lights at the crossovers.
The intersection design also includes provision for dual left turn lanes with approximately 300 feet
of storage at the median U-turns on Golden Gate Parkway east and west of Airport-Pulling Road.
Based on the preliminary analysis this will provide adequate storage area between Airport-Pulling
Road and median u-turn intersections on Golden Gate Parkway.
Dual right turn lanes will also be provided on Airport-Pulling Road approaching Golden Gate
Parkway. To limit the number of weaving maneuvers at the intersection, appropriate signing will
direct northbound traffic heading to eastbound Golden Gate Parkway via the median U-turn to
use the inside right turn lane. Right turn-on-red will be prohibited from the inside right turn lane.
Traffic heading from Airport-Pulling Road northbound to westbound Golden Gate Parkway will be
directed to use the outside right turn lane, eliminating weaving maneuvers from that lane. Right
turn-on-red will be allowed from that movement.
2.6 Projected Delay/Level of Service
Table 3 summarizes the results of the preliminary traffic simulations performed using 2005 and
2025 traffic projections for the afternoon peak period. Values are shown both for the current
projections documented in the January 2003 traffic memorandum by KH&A and for the estimated
volumes assuming a 2 percent growth per year. The latter are conservative figures except for
Golden Gate Parkway westbound, as they are based on existing traffic patterns and do not
specifically account for traffic diversion due to the addition of the new interchange between 1-75
and Golden Gate Parkway. With a two percent annual growth rate, projected peak hour volumes
are on average 15 to 35 percent greater than the available approach capacity for both of the six-
lane arterials. These numbers were used to determine the earliest year that additional
improvements would be needed at the intersection.
Page 4 of 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, Florida
Table 3: Split Intersection (with median crossovers) Preliminary Analysis Summary
2005 PM Peak Analysis 2025 PM Peak Analysis
Delay Level of Service Delay Level of Service
(secs per veh) (secs per veh)
Golden Gate Parkway Westbound from 40 35 D ; D 50 110 D { F
Future Access Road to Ai~omPulling
Road
Golden Gate Par~ay Eastbound from 45 65 D ~ E 115 ~ 160 F ~ F
~ar's Paw to Air~-Pulling Road
Airpo~-Pulling Road No~h~und to 30 75 C ~ E ~ 40 ~ 100 D ~ F
Golden Gate Parkway West~und
Signal
40 35 D C 40 ;: 120 D'~ F
Airpod-Pulling
Road
Southbound
to
Golden Gate Parkway' Eastbound
Signal
Delays are in seconds per vehicles and include the following movements:
Westbound: from Future Access Road to Airport-Pulling Road.
Eastbound: from Bear's Paw Entrance to Airport-Pulling Road.
Northbound: south of Golden Gate Parkway Westbound Lanes.
Southbound: north of Golden Gate Parkway Eastbound Lanes.
2.7 Potential Project Phasing
The results of the preliminary traffic simulation were evaluated in order to identify a time frame for
additional improvements at the intersection. These improvements would include constructing
three elevated eastbound and westbound lanes along Golden Gate Parkway between the median
U-Turns. Because the proposed elevated lanes could be constructed within the wide median
provided in the proposed layout, this approach would allow the County to provide adequate levels
of service at the intersection with minimum disruption of traffic in the future.
To estimate the time-frame when additional improvements will be necessary, the average delay
based on 2005 projections was compared to the average delay with 2025 PM peak hour traffic
volumes. The projected yearly growth rate between the two analysis years was then applied to
the average delay to estimate the approximate year when additional improvements will be
needed. Based on this methodology, it is estimated that the elevated lanes along Golden Gate
Parkway may be needed between 2010 (based on conservative two percent annual growth rate)
and 2015 (based on KH&A 2025 volume projections), when the at-grade intersection is likely to
reach a v/c ratio of 1.0.
This preliminary analysis is based on available data. A final recommendation of the projected
phasing and specific geometry should follow a more thorough analysis of the traffic projections,
traffic operation, constructability and other impacts associated with the project.
Page 5 of 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, Fiorid,n
2.8 Preliminary Conclusions: Golden Gate Parkway/Airport-Pulling Road
Because the existing planned footprint for. the Golden Gate Parkway Overpass of Airport-Pulling
Road is clearly a constraint for any alternatives, the Split Intersection (with median crossovers)
was determined to be the most viable. The advantages and disadvantages of the Split
Intersection (with median crossovers) are as follows:
Advantages Compared to Overpass:
· Significantly lower initial construction costs and facilitates funding reallocation to other priority
projects.
· Provides improved level of service compared to existing intersection.
· Reduces the duration of the initial construction period and allows less disruptive maintenance
of traffic impacts.
· Perceived as less obtrusive ir~ the short term.
· Allows more flexibility with likely ultimate Golden Gate Parkway corridor improvements.
· Allows further consideration of long-term improvements after the 1-75/Golden Gate Parkway
Interchange is in place, actual traffic levels are known and the updated regional traffic
assignment model has been validated.
Disadvantages Compared to Overpass:
· Requires driver acclamation to different turning movements; additional driver educational and
enforcement efforts are necessary.
· Longer-term construction costs likely to be higher given escalation over time and additional
contractor mobilization costs and some additional reconstruction costs.
· Will not provide a comparable level-of-service over the long-term and the duration of peak
congestion hours will be longer compared to the interchange design.
· Some additional redesign costs would be incurred to adjust the current 60 percent plans to be
compatible with the interim Split Intersection (with median crossovers) design and assure
minimal later "wasted cost" for the overpass construction.
3.0 Golden Gate Parkway/Santa Barbara Boulevard
The intersection of Golden Gate Parkway and Santa Barbara Boulevard also was analyzed for
potential application of an "unconventional" intersection design. Both arterials are currently four-
lane divided roadways with plans to widen Golden Gate Parkway to six lanes west of Santa
Barbara Boulevard.
Page 6 of 8
Final Report
Preliminary Evaluation of Unconventional intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, Fiodda
3.1 Initial Observations
Traffic operations at the intersection were observed during both morning and afternoon peak
periods. Congestion was mainly in the eastbound direction during the afternoon peak period, with
queues extending to just east of the bridge over 1-75. Both through and left turn movements were
equally heavy. Most vehicles are turning left from Golden Gate Parkway westbound to Santa
Barbara northbound, ultimately headed west on Green Street. Most of the vehicles continuing
eastbound on Golden Gate Parkway travel equally north and south on SR-951.
During the morning peak period, the heaviest movements were the right turn from Santa Barbara
Boulevard southbound to Golden Gate Parkway westbound. The queue on Golden Gate
Parkway extended beyond 53rd Street during the observation period.
3.2 Potential Short-Term Improvements
The current signal timing and phasing of the intersection allows most of the vehicles to clear the
intersection in the non-peak directions during peak periods. Improving the turning radius as well
as providing for an overlap phase can improve the efficiency of the exclusive right turn from
southbound Santa Barbara Boulevard to westbound Golden Gate Parkway. That phase would be
concurrent with the existing phase provided to the eastbound and westbound left turn
movements.
3.3 Determination of Long-Term Improvements
Identification of potential future long-term improvements to the intersection could not be identified
based on the available data. The current projections reflect the roadway network included in the
latest Cost Feasible Plan adopted by the County, except for the number of lanes on Santa
Barbara Boulevard. Subsequent to the adoption of the Cost Feasible Plan, the number of lanes
on Santa Barbara Boulevard, north of Golden Gate Parkway, was reduced from six to four lanes.
Green Street Extension to Livingston Road is also not included in the Cost Feasible Plan and
would have a significant impact on the projections at Santa Barbara Boulevard and Golden Gate
Parkway.
The evaluation of potential improvements at Santa Barbara Boulevard and Golden Gate Parkway
should be based on a thorough knowledge of existing travel patterns. This information can be
obtained by performing daily and peak hour turning movement counts at key locations within the
area formed by Livingston Road, Golden Gate Parkway, Santa Barbara, and Pine Ridge Road.
This will in turn allow the County to evaluate, validate, and make necessary adjustments to the
future projections produced by the regional model. The evaluation should also account for the
impacts of proposed improvements along Golden Gate Parkway and on 1-75 on future traffic
patterns at the intersection of Santa Barbara Boulevard. The proposed improvements to the
intersection should take into consideration surrounding land-uses. This intersection appears to
have limited potential for application of "unconventional" design, however, certainly warrants a
more thorough analysis.
Page 7 of 8
Final Report
Preliminary Evaluation of Unconventional Intersection Designs
Golden Gate Parkway/Airport-Pulling Road Intersection
Collier County, FIorid~
4.0 Recommendation
Based on the significance of the pending Golden Gate Parkway/Airport~Pulling Road Overpass
investment ($28 million) and the increased traffic demand throughout the Golden Gate Parkway
Corridor (Santa Barbara Boulevard to US-41), PB believes a more intensive Corridor Congestion
Management Study is both appropriate and essential. This study would provide a basis for
strengthening the comprehensive and integrated investment strategy for the entire Corridor.
Based on this evaluation and preliminary conclusions and the advantages and disadvantages
associated described previously, PB believes there are further significant opportunities and
recommend continued consideration of unconventional design alternatives.
The comprehensive study would have three specific objectives:
· Refinement of overpass alternatives at the Golden Gate Parkway and Airport-Pulling Road
intersection, including detailed traffic operation evaluations and design recommendations
compatible with a phased Split Intersection (with median crossovers)/Overpass intersection;
· Development of a plan to address the demand/constraint problems at Golden Gate Parkway
and Santa Barbara Boulevard;
· Development of the short-term and long-range improvement concepts for the entire Golden
Gate Parkway Corridor between Santa Barbara Boulevard and US-41.
Page 8 of 8
EXHIBIT A
THE SPLIT INTERSECTION (with median crossovers): WHAT IT IS?
History
The first known application of the Split Intersection concept is in Tel Aviv, Israel, converted from a conventional
intersection design in 1975. The design proved to be successful, providing greater intersection capacities than
expected, and postponed the construction of a complete grade-separated design at this location. Several other Split
Intersections have been constructed in Israel and were later converted to diamond at-grade intersections. The
design has been used as temporary measure during interchange construction in the U.S., but there is presently no
known longstanding specific application.
Operations
The Split Intersection (with median crossovers) separates traffic flow on the mainline into offset one-way roadways,
resulting in two intersections with the cross street
Figure 1: Split Intersection Design Concept
within 200 to 300 feet. The concept is similar to a
conventional diamond interchange, yet without
grade-separating the roadways. The separation
of roadways and reduced cycle length and
improved signal coordination can provide greater
efficiency and higher capacity compared to the
conventional intersection design.
The two intersections are controlled by
coordinated signals and each intersection is
reduced to three signal phases. The design can
be further modified to include indirect left-turn
movements using directional U-turn crossovers,
eliminating the need for left turn bays on the
cross street and reduces signal operations to two
phases.
Design
Considerations for a successful Split Intersection (with median crossovers) design include:
· The distance between intersections must be sufficient to store projected left-turn volumes to avoid potential
spillbacks and/or locking through and turning movements on the cross street.
· It is preferable that the signals at the two intersections be
controlled by a single controller to avoid the operational
inefficiencies that would occur should the coordination of
individual signals' timing fail.
· The Split Intersection (with median crossovers) requires more
right-of-way than most other unconventional intersection
designs, and the design's greatest impacts are closest to the
intersection, where right-of-way may be more difficult to acquire
under a design retrofit scenario. ~:~:;;~
Figure 2: Median U-Turn Signing
Research
Several engineering studies have simulated operations comparing Split Intersections to conventional intersection
designs. Their results show that the Split Intersection has great efficiency potential with delay reductions of 40 and
60 percent under certain high-volume scenarios. Both studies attribute operational timesavings to the reduction in
signal phases that yield greater arterial green time and shorter cycle lengths.
Intersection Vehicular/Pedestrian Safety
While no specific accident studies are available, there is valid reason to assume that the Split Intersection design
would reduce collisions and the rate of severity of those collisions compared to the conventional intersection by
reducing and separating vehicle conflict points. Left turns from the arterial to the cross street are without opposing
movements. Pedestrians have an additional intersection to cross but each intersection crossing is narrower, has
fewer opposing vehicle conflicts, and potentially shorter cycle lengths.
When to Consider
The Split Intersection is best suited for isolated and congested suburban intersections where the total intersection
volume is greater than 4,000 vehicles per hour (vph) with mid to high levels of left-turning traffic. The Split
Intersection concept can be particularly applicable where the creation of a grade-separated diamond interchange is
planned in the future, causing a delayed (or eliminated) need for an expensive grade-separation.
HOW WOULD IT WORK AT THE GOLDEN GATE/AIRPORT-PULLING ROAD INTERSECTION?
Drivers on Golden Gate Parkway will experience operations that are more typical at conventional intersections. Both
lefts and right will be made at the intersection. Left turns will have dual storage bays and turn onto the storage area
between the EB and WB Golden Gate intersections with Airport-Pulling Road. The 150-plus feet of separation
between intersections provided within the footprint of the proposed interchange design should provide adequate for
left turn storage in the three lanes between the intersections. If the through and left turn volumes on Golden Gate
Parkway are extremely directional in the peak periods, the signal phasing may be altered to allow left turns in the
busiest direction some additional beginning
green time so that motorists do not have to
wait in the storage area between the
intersections.
Through and right turn movements on
Airport-Pulling Road approaching Golden
Gate Parkway remain conventional;
however, the left turn movements are made
by turning right first onto Golden Gate
Parkway and proceeding 500 to 600 feet to
the U-turn movement in the median. They
proceed around the U-turn and become
through movements at the Airport-Pulling
Road intersection. This movement, known
as the Median U-turn Crossover, has been
successfully designed, signed and operated
at over 1,000 intersections in Michigan and
other parts of the country.
WHAT ARE THE FUTURE
IMPLICATIONS?
Figure 3: Split intersection (with median crossovers} Concept at
Golden Gate Par~ay and Airport-Pulling Road intersection
The Split Intersection (with median crossovers) design may significantly postpone construction of an interchange at
the Golden Gate/Airport-Pulling Road intersection.
Constructabiiity
The Split Intersection (with median crossovers) could be constructed in the same footprint as the interchange,
essential building the ramp roadways already in design for the interchange. When the future overpass roadway is
needed, the bridge could be constructed without extended interruption of traffic because the maintenance of traffic
roads would already be constructed. There would be some additional construction costs to re-construct the single
point intersection and the initial split roadways would have three lanes instead of the two lanes for the ultimate
design.
The Split Intersection (with median crossovers) also could be built in a shorter construction period, and can be
constructed before the opening of the new 1-75 interchange west of Livingston Road. Further, the design allows for
future flexibility - as both the conventional interchange could be built if 2025 traffic demand trends begin to be
realized, or, if the initial Split Intersection (with median crossovers) concept is successful, the concept could be
carried through additional intersections along Golden Gate Parkway at perhaps less cost than the interchange
design.
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PRESENTED TO THE JOINT CITY/COUNTY WORKSHOP
JANUARY 5, 2004
EXECUTIVE SUMMARY
A REVIEW OF ALL FEASIBLE PLANNING & DESIGN ALTERNATIVES
(CONVENTIONAL & UNCONVENTIONAL) FOR INTERSECTION IMPROVEMENTS
AT AIRPORT-PULLING ROAD/GOLDEN GATE PARKWAY AND THEIR IMPACT ON
ALL OTHER MAJOR INTERSECTIONS ALONG THE GOLDEN GATE PARKWAY
CORRIDOR. A GRADE SEPARATED OVERPASS IS THE ONLY ALTERNATIVE
ACHIEVING AN ADEQUATE LEVEL OF SERVICE IN 2025 WHILE PROVIDING THE
MOST COST EFFECTIVE, LONG-TERM BENEFIT TO TAXPAYERS.
OBJECTIVE: To present comprehensive data, analysis and infbrmation to the Board of County
Commissioners, Naples City Council, and Collier County citizens regarding various improvements
to the Airport-Pulling Road/Golden Gate Parkway intersection resulting from extensive study by
staff and five professional consulting firms. All conclude that a grade separated overpass is the only
alternative achieving an adequate level of service in 2025 while providing the most cost effective,
long-term benefit to taxpayers.
CONSIDERATION: Collier County is approaching the completion of a $1.8 million design effort
that will substantially address existing transportations deficiencies at the intersection of Airport-
Pulling Road and Golden Gate Parkway, and more importantly, accommodate transportation needs
well into the future. This $1.8 million design cost does not include an additional $435,000 the
County has already spent on supplemental studies, analysis and reports considering alternative
improvements and impacts along the corridor. The design effort to date is in accordance with a
decade of extensive planning and preparation by City and County officials. The project, a grade
separated overpass, is one critical step in a series of improvements to occur along the Golden Gate
Parkway corridor. Such improvements include the 6-1ane expansion currently under construction,
the 1-75 interchange to be completed in 2007, and the Goodlette-Frank Road improvements to begin
early in 2005.
In reviewing a decade of planning, this project is specifically called out within the Halstatt (Grey
Oaks, Estuary & Naples Grande) Development of Regional Impacts (DRI)/PUD, which was
approved under an Interlocal Agreement between the City and the County in 1990. This
development was required to reserve the rights-of-way fbr an overpass with Golden Gate Parkway
to fly over Airport Road. An overpass was identified as a need in the Metropolitan Planning
Organization's (MPO's) Long Range Transportation Plan since 1993. The project was also
identified in the County's Transportation 5-Year Funded Work Program since 2001. In 2002, the
County received notice that it was the recipient of $7.45 million in grant funding from the State of
Florida (TOPS Grant) specifically for the proposed improvements to the Parkway which included an
overpass to handle the traffic increase from the new 1-75 interchange. As part of the overall corridor
study, as well as concerns expressed by the City of Naples, the County advanced improvements to
Goodlette-Frank Road in its 2002 update to the 5-Year Transportation Work Program.
To evaluate all conventional and unconventional alternatives to
improve the intersection and corridor, the County has worked
with five different professional consulting firms; and the City has
worked with one firm. Kimley-Horn's first study looked at
improvements to several intersections throughout the County and
evaluated those intersections against several criteria including
existing and future traffic conditions, activity centers, whether the
roadways are evacuation routes, and parallel roadway options.
The Grade Separation Study indicated that even with at-~ade
intersection improvements this intersection would fait from a
level of service standpoint, which would cause a severe delay to
the transportation system. Even if at-grade improvements were
designed to include free flow rights and triple lefts along with six
through lanes for each approach, the intersection still fails to
operate at an acceptable level-of-service (LOS) in 2025.
Additional analysis in the report was undertaken to estimate the user benefits of an Overpass at this
location. It is estimated that over 550,000 hours of delay per year could be saved based on 2025
traffic conditions at a cost savings of $2.9 million. In addition the overpass is projected to reduce
traffic crashes and save motorists approximately $130,000 per year.
Subsequent to Kimley-Horn's ,,.a,,
sLu,~: of conventional, at-grade
improvements, Kimley Horn prepared a Technical Memorandum in
2001, which reviewed the types of overpass structures that could
operate most efficiently and at the greatest level of safety. Structures
that were considered include diamond, cloverleaf, trumpet and single
point urban interchanges (SPUI). in summary, Kimley-Horn states,
"the combination of relatively high capacity and low right-of-way
costs makes the SPUI an ideal candidate for urban arterials".
The need for a grade separated overpass at Airport Pulling Road and
Golden Gate Parkway was further evaluated under a contract with
RWA Consultants who were tasked with the refinement of design
traffic movements to develop an overpass concept within reserved
rights-of-ways. RWA was also
charged with coordinating
public involvement activities to develop a concept that would be
consistent with the expectations of quality as characterized by
the community. County staff and RWA met with the Board of
County Commissioners (BCC), the Naples City Council on
February 6, 2002, Bear's Paw on April 4, 2002 and held
Count?vide public meetings on February 11. 2002 and March
4, 2002 to present the conceptual plan and gain input into the
design of this project. This concept plan was finalized in
February of 2002 and it included almost $4 million in
architectural and landscaping features to establish a more
human scale to the structure and to serve as the gateway into the
City of Naples. On May 14, 2002, County staff received
authorization from the BCC to begin design and engineering
with RWA based on the work accomplished through the conceptual design study.
In late 2002, the City of Naples asked Kimley-Horn to look at the traffic impacts associated with the
future interchange and overpass. This study was undertaken to determine the traffic conditions at the
intersections of Airport Pulling Road and Goodlette Frank Road. The results again indicated that the
intersection at Airport Pulling Road fails in 2025 during both AM and PM peak hour conditions even
with the best conventional at-grade solutions. With an overpass, the intersection would operate at an
acceptable LOS for peak hour conditions in 2025. Kimley-Horn also determined that the
intersection at Goodlette Frank Road is projected to fail fbr both the AM and PM peak hours with at-
grade improvements within the existing right-of-way in 2025. It should also be noted that the
intersection operates at a LOS F for the peak hour conditions today in this analysis and is projected
to fail with or without the overpass at Airport-Pulling Road. At the January 7, 2003 City/County
joint workshop, Kimley-Horn confirmed the need fbr an overpass at Airport-Pulling Road and
concluded the need for an overpass at Goodlette-Frank Road. However, they assumed that they
would have to stay within the current ROW. County staff stated that because the primary movements
are turning movements (unlike Golden Gate Pkwy. at Airport) the intersection should be able to be
addressed with at-grade improvements. Subsequently, the County and City have been cooperatively
working with American Consulting Engineers (ACE) to design improvements to the intersection at
Goodlette-Frank Road (as well as that segment of Goodlette-Frank Road between the Parkwav and
Pine Ridge Road). The current design creatively calls for improvements that bypass westbound'right
turns outside the existing right-of-way. The design is quickly approaching 30% complete and will
provide for an acceptable level of service today and through 2025.
Kimley-Horn's study utilized the MPO's 2025 traffic model, which includes two Gordon River
Bridges. Subsequent to the Ci~/County workshop, Kimley-Horn was asked by the City to remove
the bridges from the model and determine the impacts along the corridor. Kimley-Horn concluded
that without the bridges, delay and extended queue lengths already experienced along the corridor
would increase considerably. At a City Council Meeting, these results were discussed and concerns
were raised with the Overpass.
Later, in response to issues raised by the City at an MPO
meeting about the beneficial impacts of building one or two
additional bridge crossings across the Gordon River, thc
County hired the TBE Group to prepare a detailed analysis
of the costs and traffic impacts of additional bridges,.
particularly as they provide relief to Golden Gate Parkway.
In building two bridges, different scenarios were developed
to maximize diversion from Golden Gate Parkway. In
summary, the cost to establish a single bridge crossing is
estimated at $75 million. The cost to establish two bridge
crossings is estimated at $90 million. These estimates are
attributed to the acquisition of right-of-way, design,
engineering, construction, and inspection associated with
the proposed bridges and roads leading to the bridges. TBE
concluded that the bridges would improve the operation of'
the network, with primary relief to Radio Road and Davis
Boulevard rather than Golden Gate Parkway.
FINAL REPORT
In November 2003, the County contracted with Parsons
Brinkerhoff Quade & Douglas (Parsons), a transportation
firm identified by the City as uniquely qualified in
evaluating unconventional intersection designs. Parsons
visited the area and reviewed prior studies and data. They
quickly discounted previously considered unconventional
approaches such as round-a-bouts, jug-handles, continuous
flow intersections and quadrant roadways because of the
volume of traffic seen at this intersection and right-of-way
constraints. Parsons found that only grade separation would
meet the 20-year design needs (see Figure 1 below).
However, Parsons did recommend a split intersection /
median u-turn concept as a possible interim solution.
Parsons proposed that this unconventional concept could
likely fit within the dedicated right-of-way for an ultimate
overpass. Parson also estimates that grade separation would
' be needed between 2010 and 2015; the earlier date liketv if
the corridor experiences a 2% a year growth rate which Parsons raised as a likely probability
based on historical growth along the corridor. They noted that a split intersection design has been
used as a temporary measure during
interchange construction in the U. S., but
there is presently no known longstanding
specific application. In whichever year
grade separation becomes necessary, it is
estimated that $3.5 million worth of
construction associated with the
unconventional design would be disrupted
and/or removed as part of an overpass
construction. The unconventional nature of
Figure I: 2025 Volume-to-Capacity Analysis Results
2025 PM
INTERSECTION DESIGN Volume-to~
I Capacity Ratio
Conventional intersection 1.42
Sing!e 1~ 0~ o~erpass ¢lanned)
Median U-Turn (crossovers only on GGP) [ 1.21
Continuous Flow Intersection i 1.05
Split Intersection {with median crossovers} [ 1.11
E~hel:0n InterChange~ (grade: se~arati®) [ 0 98
V/C Ratio above 1.0 = greater delav and longer peak volume tiine.
such a design requires significant driver acclamation, education and special law enforcement.
Lastly, the County has been working with Post Buckley Shuh and Jemigan (PBS&J), another
leading transportation consulting firm, to evaluate future traffic conditions along Golden Gate
Parkway from Santa Barbara Boulevard to U.S. 41. Two specific assignments were given. The
first included the evaluation of different build scenarios for the Golden Gate Parkway
intersections with Goodlette-Frank Road and Airport-Pulling Road in 2005 and 2025. The
second assignment focused on the evaluation of different traffic scenarios due to the
implementation of a second Gordon River bridge crossing. PBS&J's results are best summarized
in Tables 1 and 2. Findings from the first assignment as depicted in Table 1 revealed the
following:
· Operations at US 41 and at Santa Barbara Boulevard are relatively unaffected by the specific
improvement decision at the Airport Road and Golden Gate Parkway intersection or by the
possible addition of two Gordon River Bridges
· The addition if two Gordon River Bridges will slightly reduce delay at Goodlette Frank
Road, but add more delay at Livingston Road regardless of the specific improvement
decision at the Airport Road and Golden Gate Parkway intersection
4
· Given that all Airport Road at Golden Gate Parkway intersection alternatives, when
optimized, do not significantly impact other intersections along the corridor, Table 1~ below
provides the best tool to evaluate the corridor operations and cost of the Airport Road at
Golden Gate Parkway improvement options.
An overpass at Airport-Pulling Road provides significant benefit to the operation of the
intersection well into the future;
· Alternative improvements, such as a westbound bypass, at the intersection of Goodlette-
Frank Road significantly improve the operation of th~ intersection.
· In 2005, the signalized intersections within the study corridor are expected to operate better
than a LOS 'D', with the proposed improvements;
In 2025, the following intersections along the Parkway are
expected to operate below LOS 'D' with the proposed
improvements: Goodlette-Frank, Livingston, Santa
Barbara (which is policy constrained). However, only
Santa Barbara will operate below a LOS E (the county'S'
minimum standard) for portions of the day.
Findings from the second assignment as depicted in Table
2 revealed that an overpass at Airport-Pulling Road, along
with a second Gordon River bridge crossing, provides the
greatest savings in travel time, delay and fuel consumption
along the Parkway corridor when compared to all other
alternatives. The alternative of best conventional at-grade
improvements, without a second Gordon River bridge
crossing, is used as the baseline by which other
alternatives are gauged. The baseline alternative has a cost
of approximately $12 million. Other alternatives that were
considered include:
1. An overpass without additional Gordon River bridge crossings;
2. At-grade improvements at Airport-Pulling Road with two Gordon River bridge crossings;
3. An overpass with two Gordon River bridge crossings;
4. Split intersection / median U-turn concept without additional Gordon River brid~oe
crossings; ~
5. Split intersection / median U-turn concept with two Gordon River bridge crossings.
The PBS&J findings confirm the results of all prior studies that the only conventional or
unconventional improvement that meets the needs in 2025 is grade separation. Their analysis
showed that the overpass does not adversely impact the other intersections along the corridor and
that the overpass, even without two new bridges, provides for nearly a 20% reduction in travel time
over the entire corridor. Even with 4-lanes on a north Gordon River bridge crossing and 2-lanes on a
south bridge crossing, the addition of two new bridges does not provide sufficient relief to Golden
Gate Parkway traffic to eliminate the need for grade separation. Lastly, they found that the split
intersection with median u-turns would initially provide better operations than at-grade conventional
improvements, but would actually operate less effectively than conventional at-grade intersection
improvements in 2025. Neither the split intersection nor the conventional at-grade improvements,
even when combined with the additional bridges, would meet the 2025 traffic at an acceptable LOS.
FISCAL IMPACT: The Overpass is estimated to cost $27.2 million, which is to be funded by Gas
Taxes, Impact Fees and a portion of the TOPS grant.
GROWTH MANAGEMENT: The design., construction, and all-inclusive detail analysis of a
grade separated overpass is consistent with the Growth Management Plan and the MPO's Cost
Feasible Plan.
RECOMMENDATION: To recognize that an exhaustive analysis of all conventional and
unconventional improvements concludes that a grade separated overpass is the only alternative
achieving an adequate level of service in 2025. Secondly, to recognize that implementation of a
split intersection with median u-tums would only address deficiencies for a short duration even if
additional bridges were constructed and, therefore, construction of an overpass at the outset would
deliver the most cost effective solution meeting the long-term needs of the entire county with the
least construction disruption. And lastly to recognize that the current overpass design includes $4
million in aesthetic enhancements to maintain community character.
Prepared by:
Gregg R. Strakaluse, P.E.
Director, Engineering & Construction Management
Date:
Reviewed by:
Don Scott, AICP
Director, Transportation Planning
Date:
Reviewed and Approved by:
Norman Feder, AICP
Transportation Administrator
Date: