HomeMy WebLinkAboutTIMBERLINE FARM MASTER PLAN - 42-89 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDY0
TIMBERLINE FARM
SITE ACCESS STUDY
FORT COLLINS, COLORADO
AUGUST 1989
Prepared for:
The Group, Inc.
425 West Mulberry Street
Fort Collins, CO 80521
Prepared by:
MATTHEW J. DELICH, P.E.
3413 Banyan Avenue
Loveland, Colorado 80538
Phone 303-669-2061
1-1
8
EXECUTIVE SUMMARY
Timberline Farm is a proposed development located near
the intersection of Harmony Road and Timberline Road. This
traffic_ impact study involved the steps of trip generation,
trip distribution, trip assignment, capacity analysis,
traffic signal warrant analysis, signal progression analysis,
and accident analysis.
This study assessed the impacts of Timberline Farm on
the short range (1992), intermediate range (1995), and long
range (2010) street system in the vicinity of the proposed
development. As a result of this analysis, the following is
'
concluded:
- The development of Timberline Farm is feasible from a
traffic engineering standpoint. At full development as
proposed, approximately 1.4,000 trip ends will be generated at
this sit.e daily.
- The Harmony/Timberline intersection currently
operates acceptably with signal control and the existing
geometrics. Phasing changes are recommended in order to
improve the operation and delay geometric improvements on the
'
north leg of Timberline Road.
- By 1992, given the development of Parcel A of
Timberline Farm, Phase 1 of Collindale Business Park, and an
increase in background traffic, the signalized intersection
of Harmony/Timberline will operate acceptably with the
existing geometrics and signal phasing changes. At this
level of development, Timberline Road can remain a two lane
street with auxiliary lanes at Caribou. The Timberline/
Caribou intersection will operate acceptably with stop sign
control.
- No new signals are warranted in the short or
'
intermediate range future. With full development of
Timberline Farm and other nearby properties, signals will
likely be'warranted at the Timberline/Caribou and Timberline./
Access C intersections.
A signal at the Timberline/Caribou and Timberline/
Access C intersections will not negatively impact the signal
progression along Timberline Road.
- By 1995, given the development of Parcels A and B of
' Timberline Farm and background traffic, the Harmony/
Timberline intersection will operate acceptably with the
existing geometrics and phasing improvements recommended
earlier. It is recommended that at this level of
development, two points of access to Timberline Road be
developed. One should be at. Caribou and the other at either
Access C or Access E.
- By 2010, the Harmony/Timberline intersection will
operate acceptably in the morning peak hour and at level of
service E in the afternoon peak hour with geometric
improvements to both Harmony Road and Timberline Road. The
necessary geometrics are shown in Figure 12. With
sgnalization, the Timberline/Caribou and Timber line/Access C
intersections will operate acceptably. The other
intersections will operate acceptably with the recommended
geometrics. The Harmony/Access A intersection will operate
acceptably as a right-in/right-out/left-in intersection.
- With the recommended control and geometrics, the
accident rate should be at an acceptable level for typical
urban conditions.
0
I. INTRODUCTION
This: traffic impact study addresses the capacity,
geometric, and control requirements at and near a proposed
development knot -in hereinafter as Timberline Farm. it is
located near the intersection of Timberline Road and Harmony
Road in Fort Collins, Colorado.,
1
Cueing the course of the analysis, numerous contacts
t,lere made viith the developer (The Group Inc.), the planning
consultant (Cityscape), and the Fort Collins Traffic
Engineering Department. This study generally conforms to the
'
format set forth in the Traffic Impact Study Guidelines. The
study involved the following steps:
Collect physical, traffic_ and development data.
Perform trip generation, trip distribution, and trip
assignment.
- Determine peak hour traffic volumes and daily traffic
volumes.
- Conduct capacity and operational level of service
analyses on key intersections and roadway sections.
- Analyze signal warrants and signal progression.
- Analyze potential changes in accidents and safety
considerations.
II. EXISTING CONDITIONS
The location of Timberline Farm is shown in Figure 1.
It is important that a thorough understanding of the existing
conditions be presented.
Land Use
Land uses in the area are primarily vacant, commercial,
agricultural, or residential. Residential development exists
to the east, west and north of Timberline Farm. Some vacant
land exists to the west across Timberline Road. An agricul-
tural use exists to the south across Harmony Road. Small
commercial uses exist to the west of Timberline Road. Land
i
in the area i s essentially flat. The center of Fort Collins
lies to the north of Timberline Farm.
Roads
The primary streets near Timberline Farm are Harmony
Road and Timberline Road. Timberline Road is west of
Timberline Farm. It is a north -south street designated as a
major arterial on the Fort Collins Master Street Plan. In
this area., it has a two lane rural cross section with
insufficient auxiliary turn lanes at Harmony Road. The
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SITE LOCATION Figure 1
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posted speed limit is 40 mph. Sight distance isgenerally
not a problem along Timberline Road. The Harmony/Timberline
intersection has signal control. The nearest other signal
along Timberline Road is at Horsetooth to the north.
Harmony Road is south of this site. It is an east -west
street designated as a major arterial on the Fort Collins
Master Street Plan. Adjacent to the site, Harmony Road is
built to a four lane divided highway cross section. It has a
rural cross section with a grass median. There are left -turn
and right -turn lanes at the Harmony/Timberline intersection.
The posted speed on Harmony Road is 55 mph with a reduction
to 48 mph approaching signalized intersections.
An access control plan for Harmony Road (S.H. 68) has
recently been completed by the City of Fort Collins and the
Colorado Department of Highways. The proposed Timberline
Farm accesses to Harmony Road are in conformance with that
plan. This site access study will address the access
locations on both Harmony Road and Timberline Road.
IExisting Traffic
Daily traffic flow
machine counted volumes
is shown in
conducted by
Figure 2. These are
the City of Fort Collins
in 198E and the Colorado
Department
of Highways
in 1983.
Peak hour turning movements
obtained
in June and
July of 1989
are shown in Figure 3.
Raw traffic
count data is provided in
Appendix A.
1 Existing Operation
The Harmony/Timberline and Timberline/Caribou intersec-
tions, which were counted in June and July of 1989, were
evaluated regarding operational efficiency. They were
evaluated using existing control with existing geometrics and
the volumes shown in Figure 3. The peak hour operation is
shown in Table 1. Calculation forms are provided in Appendix
B. Appendix C describes level of service for signalized and
unsignalize.d intersections from the 1985 Highway Capacity
Manual. With the existing signal control and geometrics, the
Harmony/Timberline intersection operates acceptably.
However, the southbound left turns do not always clear due tc
the insufficient geometrics and the high volumes. This can
be remedied by introducing separate phases for the north -
south traffic. This phasing scheme will introduce some extra
lost time to each cycle, which in turn deteriorates the level
of service slightly. The level of service still remains in
the "A" category. The Timberline/Caribou intersection
1
operates acceptably with the existing stop sign control.
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6125 (19 3)
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HARMONY �42b �1983�
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RECENT DAILY TRAFFIC COUNTS Figure 2
AM/PM
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1 1989 PEAK HOUR TRAFFIC
Figure 3
Tabl e 1
Existing Peak Hour Operation
.Intersection AM Peak Hour PM Peek Hour
Harmony/Timberline (signalized)
Existing Geometrics/Phasing A A
Existing Geometric=_- & Separate A A
Phases N/S
Timberline/Caribou
WB LT C D
WB RT A A
SB LT A A
Table 2
Trip Generation
Daily A.M. Peak P.M. Peak,
Land Use Trips Trips Trips Trips Trips
in out in out
Parcel A
Single Family - 69 DU 690 14 38 43 26
Parcel B
Single Family - 57 DU 570 12 31 36 21
Parcel C
Multi -family - 160 DU 1055 18 65 65 35
Parcel D
Business Services - 2985 104 26 109 154
75 KSF
Parcel E
Retail/Business Parke- 7655 22.9
190 KSF
Parcel F
Business Services - 875 31
22 KSF
Parcel G
Office Park - 26 KSF 295 43
Total 14125 451
67 285 369
7 32 45
5 5 33
239 575 683
III. PROPOSED DEVELOPMENT
Timberline Farm is a proposed commercial/residential
development located near the intersection of Harmony Road and
-
Timberline Road in Fort Collins. Figure 4 shows a schematic
of the site plan of Timberline Farm indicating location of
the uses shown in Table 2, Trip Generation. The short range
analysis (1992) included 68 single family residential lots
indicated in Table 2 as Parcel A. An intermediate range
(1995) of development included Parcels A and B. The long
range analysis (2010) included full development of the
Timberline Farm development along with other proposed/
expected Uses to the north and west of this site and an
increase in background traffic in general accordance with the
North Front Range Corridor Study.
Trip Generation
Trip generation is important in considering the impact
of a development such as this upon the existing and proposed
street- system. A compilation of trip generation information
was prepared by the Institute of Transportation Engineers in
1.976, updated in 1987, and was used to project trips that
would be generated by the proposed uses at this site. Table
2 shows theexpected trip generation on a daily and peak hour
basis. No adjustments were made for transit or ridesharing.
Therefore, the trip generation can be considered conserva-
tively high•.
Trip Distribution
Two directional distributions of
the generated trips
were determined for Timberline Farm.
Distributions from the
commercial uses used population as the
attraction variable in
the gravity model. Distributions from
the residential use
used employment as the attraction variable
in the gravity
model. Future year data were obtained
from information
supplied by the Fort Collins Planning
Department. The trip
distribution is shown in Figure 5.
Traffic Projections
Traffic projections for the short
range time period
(1992) were obtained by factoring the
existing traffic by 106
percent per year for Harmony Road and
for Timberline Road to
obtain the expected traffic in 1992.
Also included in the
traffic projections were developments
to the north
(Collindale Business Park, Timberline-Horsetooth
Property,
and Fox Meadows) which are likely to be
partially developed
'
by 1992. This traffic is identified as
background traffic
which passes by the site on Timberline
Road. Figure 6 shows
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1 SITE PLANT Figure 4
Residential / Commercial
TRIP DISTRIBUTION
Figure 5
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HARMONY
20,000
1992 DAILY TRAFFIC Figure 6
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1995 DAILY TRAFFIC Figure 7
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HARMONY
40�►
2010 DAILY TRAFFIC
Figure 8
the expected 1992 daily traffic considering the site
generated traffic and the background traffic.
Traffic projections for the intermediate range time
period (1995) were obtained by factoring the existing traffic
by 113 percent per year for Harmony Road and for Timberline
Road to obtain the expected traffic in 1995. Also included
in the traffic projections were developments to the north
(Collindale Business Park, Timberline-Horsetooth Property,
and Fox Meadows) which are likely to be partially developed
by 1995. This traffic is identified as background traffic
which passes by the site on Timberline Road. Figure 7 shows
the expected 1995 daily traffic considering the site
generated traffic and the background traffic.
For 20+ year projections (year 2010), the usual source
for projections is the Traffic Flow Map as provided by the
City. However, the last Traffic Flow Map provides
projections for only the year 2000. The North Front Range
Corridor Study was also used as a reference. Therefore, an
estimation was made of traffic in this area by the year 2010
using the latest Traffic Flow Map, the North Front Range
Corridor Study, and the knowledge of what has been occurring
and what is expected to occur in this area of Fort Collins.
These daily projections are shown in Figure 8. These volumes
'
assume that the system indicated on the Fort Collins Master
Street Plan is in place.
Trip Assignment
Trip assignment is how the generated and distributed
trips are expected to be loaded on the street system. The
assigned trips are the resultant of the trip distribution
process. Figure 9 shows the short range morning peak hour
assignment and the afternoon peak hour assignment of Parcel A
of Timberline: Farm generated traffic plus background traffic.
Figure 10 shows the intermediate range morning peak hour
assignment and the afternoon peak hour assignment of Parcel A
and 8 of Timberline Farm generated traffic plus background
traffic. Figure 11 shows the long range peak hoer assignment
of full development of Timberline Farm with background
'
traffic, assuming implementation of the road network
indicated on the Fort Collins Master Street Plan.
Signal Warrants
As a matter of policy, traffic signals are not installed
at any location unless warrants are met according to the
Manual on Uniform Traffic Control Devices. However, it is
possible to determine whether• traffic signal warrants are
likely to be met based upon estimated ADT and peak hour
signal warrants shown in Appendix D. Using the daily traffic
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HARMONY
AM/PM
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Figure 9
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G I N
AM/PM
1995 PEAK HOUR TRAFFIC Figure 10
G I N
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2010 PEAK HOUR TRAFFIC Figure 11
0
volumes
shown in Figure 6 and
the peak hour volu.m.es shown in
Figure
9, additional signals
along either Timberline Road or
1
Harmony
Road will not likely
be needed in the short range
future.
Using the daily traffic volumes shown in Figure 7 and
the peak hour volumes shown in Figure 10, additional signals
along either Timberline Road or Harmony Road will not likely
be needed in the intermediate range future.
Using the traffic volumes in Figures 8 and 11,.a traffic
signal is likely to be warranted at the Timberline/Access C
and Timberline/Caribou intersections. Later in this report,
these intersections will be evaluated with regards to signal
progression.
Signal Progression
Signal progression was evaluated prior to intersection
operational analysis in order to evaluate whether the
potentially warranted signal at the Timberline/Access C
intersection can fit into a signal progression pattern along
Timberline Road. Other signals along Timberline Road were
inserted based upon judgment and included signals which would
yield a reasonable level of analysis. Signal progression was
also analyzed along Harmony Road as it relates to the Harmony
Road Access Control Plan.
The technique used in the signal progression analysis
was a. computer program called Signal Progression Analysis
(SPAN) prepared by the University of Florida Transportation
Research Center. Its main functions include:
- Interactive entry of arterial system data.
- Display a time location diagram which provides
graphical representation of the quality of arterial
progression.
- Printing of a time --space diagram to show the quality
of progression.
Optimization of signal offsets for arterial pro-
gression.
The program inputs are:
- Intersection location
- Cycle length
- Phasing
- Offsets
Speed
Any or all of these inputs can be changed iteratively in
achieving the optimal progression.
6-1
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The signal progression on Timberline Road was analyzed
based upon the following criteria:
- Cycle length of 90-120 seconds.
- Posted speed of 35-40 mph.
- Mainline (Timberline) G/C Ratio
Drake G/C = 0.40
Collector G/C = 0.60
Collector G/C = 1.00 (no signal)
Timberline G/C = 0.40
Big Horn G/C = 0.75 This intersection was analyzed
in another traffic study and found to be a
reasonable location for a signal and one which
would not negatively impact progression on
Timberline Road.
Caribou G/C = 0.60
Access C G/C = 1.00 (no signal). G/C = 0.65 (with
a signal)
Harmony G/C = 0.40
- Green time on the cross street is greater than the
pedestrian crossing time of the mainline at 4 feet
per second.
- Achieve the largest bandwidth possible along Timber-
line Road.
A number of cycle lengths and speeds were examined.
Appendix E shows four progression analyses for Timberline
Road. Page 1 shows a time -space diagram using a 90 second
cycle and 40 mph with no signal at Access C. Bandwidths of
31 seconds (34;. efficiency) are achieved in each direction.
Page 2 shows the same criteria with a signal introduced at
Access C. The bandwidths are the same as those indicated on
Page 1. Page 3 shows a time -space diagram using a 100 second
cycle and 35 mph with no signal at Access C. Bandwidths of
40 seconds northbound and 37 seconds southbound (38 %
efficiency) are achieved. Page 4 shows the same criteria
with a signal introduced at Access C. The bandwidths are the
same as those indicated on Page 3. It is concluded that a
signal at Access C will not negatively impact signal
progression along Timberline Road.
The above progression analyses are presented to show
that the Timberline./Access C signal can fit into a
progression pattern along Timberline Road. Design
progression analysis must be conducted on a regular basis
reflecting change in land use, speed, and other variables.
Operations Analysis
Capacity analyses
adjacent to Timberline
1
ate range analyses were
and Timberline/Caribou
were performed on
Farm. The short
performed on the
intersections due
6
key intersections
range and intermedi-
Harmony/Timberline,
to the proposed
0 0
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1
7
1
1
phasing of this development. The long range analyses were
performed on all the key intersections.
Using the traffic volumes shown in Figure 9 and the
existing geometrics, the intersections operate in the short
range condition as indicated in Table 3. Calculation forms
for these analyses are provided in Appendix F. The Harmony/
Timberline intersection operates acceptably with traffic
signals. It is recommended that, at a minimum, the north and
south phases be separated to allow for the heavier southbound
approach traffic to have adequate green time without con-
flicts from the northbound traffic. This phasing arrangement
will alloy) the existing geometries on Timberline Road to
remain. The stop sign controlled Timberline/Caribou inter-
section will operate acceptably. Provision of a left -turn
lane on Caribou will confine delays due to the level of
service D operation to only those vehicles desiring to turn
left from Caribou. A left -turn auxiliary lane is required at
the Timberline/Caribou intersection. The southbound left -
turn lane should be 390 feet including taper and storage.
The right -turn treatment should include a 190 foot taper and
40 foot radius. This will enable right -turning vehicles to
get out of the through lane to execute the maneuver.
Under the short range future condition, Timberline Road
can remain a. tt,io lane street with the auxiliary lanes
mentioned above. The above analyses and recommendations also
include development of Parcel A of the Timberline Farm.
Other development which may occur in the area is reflected in
the background traffic considered in these analyses.
Using the traffic volumes shown in Figure 10, the
intersections operate in the intermediate range condition as
indicated in Table 4. Calculation forms for these analyses
are provided in Appendix G. The signalized Harmony/
Timberline intersection will operate acceptably with the
phasing and geometrics suggested under the short range.
condition. The geometries on the north leg of Timberline are
not ideal. While acceptable operation is achieved, the
geometrics can be improved on the north leg by separating all
the movements. This would require a widening of the ditch
crossing located 150 feet north of Harmony Road. Since this
level of development does not cause unacceptable operation,
this widening is not recommended. The stop sign controlled
Ti'mberline'/Caribou intersection will operate acceptably
except for left -turn exits from Caribou. An additional
access to the south (Access E or D) will improve the opera-
tion on the east leg of the Timberline/Caribou intersection
by moving some of the left turns to another location.
Using the traffic volumes shown in
intersections operate in the long range
in Table S. Calculation forms for then
provided in Appendix H. It is expected
7
Figure 115 the key
future as indicated
e analyses are
that by this future
Table 3
1992 Operation
Intersection AM. Peak Hour
Harmony/Timberline (signalized)
Existing Geometrics &c Separate
Phases N/S
Timberline/Caribou
WB LT
WB RT/T
EB LT
EB RT/T
SB LT
NB LT
Caribou/Access I
NB LT/T/RT
SB LT/T/RT
EB LT
WB LT
Caribou/Access G
NB LT/T/RT
SIB LT/T/RT
EB LT
WB LT
Caribou/Access H
NB LT/RT
WB LT
A
D
A
D
B
A
A
I
A
PM Peak Hour
U
D
A
D
B
A
A
A
A
A
A
A
A
A
A
0
Tab] e 4
1995 Operation
`
Intersection AM
Peak Hour
PM Peak Hour.
Harmony/Timberline (signalized)
Existing Ceometrics & Separate
B
B
Phases N/S
Timberline/Caribou
WB LT
E
E
WB RT/T
A
A
EB LT
D
E
EB RT/T
A
A
SB LT
A
A
NB LT
A
A
Caribou/Access I
NB LT/T/PT
A
A
SB LT/T/RT
A
A
EB LT
A
A
WB LT
A
A
Caribou/'Access G
NB LT/T/RT
A
A
SB LT/T/RT
A
A
EB LT
A
A
WB LT
A
A
Caribou/Access H
NB LT/RT
A
A
WI3 LT
A
A
Tabl e 5
2010 Operation
Intersection
AM Peak Hour
PM Peak Hour
Harmony/Timberline
(signalized)
D
E
Timberline/Caribou
(signalized)
A
C
Timberline/Access C
(signaliz,ed)
A
B
Caribou/Access I
NB LT/T/RT
A
A
SEA LT/T/RT
A
A
EB LT
A
A
L-38 LT
A
A
Caribou/Access C
NB LT/T/RT
A
A
SB LT/T/RT
A
A
EB LT
A
A
WB LT
A
A
Caribou/Access H.
NB LT/RT
A
A
WB LT
A
A
Timberline/Access E
WB RT
A
A
SB LT
C
D
P
1
date (2010), Timberline Farm, as well as a number of other
parcels, will be at full development. In order to attain
acceptable operation during the morning peak hour and level
of service E operation during the afternoon peak hour at the
Harmony/Timberline intersection, it is recommended that each
approach be provided with the geometrics shown in Figure 12.
This is the best operation possible given the volumes shown'
in Figure 1.1. The Timberline/Caribou and Timberline/Access C
signalized intersections will operate acceptably. The
geometries at these intersections are also shown in Figure
12. Right -turn exits from Accesses G and E will operate
acceptably given the six. lane cross section of Timberline
Road. Left -turn exits from Access E to Timberline Road will
operate unacceptably. This is due to the high volumes
anticipated on Timberline Road rather than the generated
traffic from Timberline Farm. It is recommended that Access
E be right-in/right-out/left-in. The assigned left -turn
exits at this location do have other reasonable point.s of
left -turn egress at Accesses C and G. In accordance with the
Harmony Road Access Control Plan, Access A is intended to be
right-in/right-out/left-in. The left -turn lane at this
location should be 820 feet including storage, deceleration,
and taper. The median on Harmony Road is wide enough to
accommodate back-to-back left —turn lanes betvieen Access A and
Timberline Road. Access B to Parcel F is intended to be a
temporary right-in/right-out until access to Parcel F can be
gained from Parcel E. This temporary condition will exist if
Parcel F develops prior to Parcel E.
Accident Analysis
The recommended control devices and geometries should
minimize vehicular conflicts and maximize vehicle separation.
Therefore, the accident rate should be at its minimum for a
typical urban condition.
I V . CONCLUSIONS
This study assessed the impacts of Timberline Farm on
the short range (1992), intermediate range (1995), and long
range (2010) street system in the vicinity of the proposed
development. As a result of this analysis, the following is
concluded:
- The development of Timberline Farm is feasible
traffic engineering standpoint. At full development as
from a
proposed, approximately 140000 trip ends will be generated at
this site daily.
- The Harmony/Timberline intersection currently
operates acceptably with signal control and the existing
geometries. Phasing changes are recommended in order to
u
8
T = Taper
LONG RANGE GEOME 'RIGS Figure 12
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J
1
H
1
improve the operation and delay geometric improvements on the
north leg of Timberline Road.
- By 1992, given the development of Parcel A of
Timberline Farm, Phase 1 of Collindale Business Park, and an
increase in background traffic, the signalized intersection
of Harmony/Timberline will operate acceptably with the
existing geometries and signal phasing changes. At this
level of development, Timberline Road can remain a two lane
street with auxiliary lanes at Caribou. The Timberline/
Caribou intersect' ion will operate acceptably with stop sign
control.
- No new signals are warranted in the short or
intermediate range future. With full development of
Timberline Farm and other nearby properties, signals will
likely be warranted at the Timberline/Caribou and Timberline/
Access C intersections.
- A signal at the Timberline/Caribou and Timber line/
Access C intersections will not negatively impact the signal
progression along Timberline Road.
- By 1995, given the development of Parcels A and B of
Timberline Farm and background traffic, the Harmony/
Timberline intersection will operate acceptably with the
existing geometrics and phasing improvements recommended
earlier. It is recommended that at this level of
development, two points of access to Timberline Road be
developed. One should be at Caribou and the other at either
Access C or Access E.
By 2010, the Harmony/Timberline intersection will
operate acceptably in the morning peak hour and at level of
service E in the afternoon peak hour with geometric
improvements to both Harmony Road and Timberline Road. The
necessary geometries are shown in Figure 12. With
signalization, the Timberline/Caribou and Timberline/Access C
intersections will operate acceptably. The other
intersections will operate acceptably with the recommended
ge.ometrics. The Harmony/Access A intersection will operate
acceptably as a right-in./right-out/left-in intersection.
With the recommended control and geometries, the
accident rate should be at an acceptable level for typical
urban conditions.
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