HomeMy WebLinkAboutGATEWAY TO HARMONY ROAD PUD - MASTER PLAN - 1-88 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDYHARMONY PLAZA
SITE ACCESS STUDY
FORT COLLINS, COLORADO
DECEMBER 1987
Prepared for:
McDonald's Corporation
5251 DTC Parkway, Suite 300
Englewood, CO 80111
Prepared by:
MATTHEW J. DELICH, P.E.
3413 Banyan Avenue
Loveland, Colorado 80538
Phone 303-66?-2061
1
E<<:EGUTI4:'E El_RY1MARY
Harmony Plaza is a. proposed development located at the
intersection of College Avenue and Harmony 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 Harmony Plaza on the
short range (1?95) 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 Harmony Plaza is feasible from a
traffic engineering _standpoint. At full development as
proposed, approximately 5500 tr• i p end_. wi 1 1 be generated at
this site dai 1 y. Also considered in this analysis is the
property to the north which is expected to generate an
additional :3500 tr• i p ends per day.
- Existing operation at the Coll ege/Harmony and
Harmony/Mason intersections are acceptable with existing
geometrics.
I-
By 1? ?5, given full development of Phase I of Harmony
Plaza and an increase in background traffic, the signalized
intersection of College and Harmony will operate acceptably
with some geometric improvements. The Harmony/Mason and
College Kensington inter_.ections will operate acceptably with
signal control. With stop sign control, the Mason Street
intersections should operate at acceptable levels of service
during peak: hours.
- By 2010, the C:ol1ege.'Ha.r•monx intersection will
operate acceptably at the noon peak: and unacceptably in the
afternoon peak. However, the geome tr• i cs. shown/recommended on
Harmony Road are not at its full six lane width. The
unacceptable operation is 1 i kel y to occur for only a short
'
time on an average day. It is questionable whether the worst
case peak hour should be made acceptable. There is a point
of diminishing returns for the investment in the street. if
'
the fu 1 1 six lane width of Harmony Road is considered in this
intersection, acceptable operation during the afternoon peak
hour is attainable. With stop sign control , the Mason Street
intersections will operate acceptably. With signals at the
College/Kensington or H.a.r•monx/Ha.son intersection.., acceptable
operation wi 1 1 occur.
- Signals at the College/Kensington intersection can
fit into an existing progression band on College Avenue. The
signal does not reduce the bandwidth along College Avenue.
I
1
The bandwidth is governed by other signals along College
Avenue.
- The proposed stop sign controlled limited turn
driveway accesses to both College and Harmony wi 1 1 operate
acceptably. A right -turn auxiliary (deceleration) lane i
warranted at each. This. right -turn lane would remove
vehicles from the through traffic stream providing a. safer
condition. The following recommendations .are made with
regard to these right-in/right-out accesses:
- The access to Harmony Road is recommended since it
has a. positive effect on the operation at the
Harmony/Mason signalized intersection. It is also
possible to design an adequate right -turn
deceleration lane for this access.
- The access. to College Avenue is recommended if the
College/Kensington intersection is signalized, since
it has a positive effect on the operation at the
signalized intersection. This improved operation has
the additional positive effect of providing the
longest possible through bandwidth on College Avenue.
Without a signal at the College/Kensington i nter-
section, the effect of the right-in/right-out access
' is minimal and, as such, no recommendation can be
made.
- With the recommended control geometries, the accident
rate should be at an acceptable level for typical urban
conditions.
0
I . IP•JTRODUCTION
This site access study addresses the capacity,
geometric , a.nd control requirements .a.t and near a proposed
commercial development k:novin hereinafter as. Harmony Plaza.
It is located at the intersection of College Avenue and
Harmony Road in Fort Collins, Colorado.
During the course of the anal ys•i s., numerous contacts
1
vlere made v)ith the project planning consultant (ZVFK) and the
Fort C:ol l ins• Traffic Engineering Department. This study
generally conforms to the format set forth in the Traffic
Impact Study Guide 1 i nes.. The study involved the fol 1 ovi i ng
step=_.
Collect ph:>.=.ical , traffic and development data..
Perform trip generation, trip distribution, and trip
ass i grime t .
- Deter -mine peak hour traff i c uol umes and daily traff i c
volumes..
- Conduct capacity and operational level of service
analyses on b:ey intersections and roadv:tay sections.
'
_ Analyze signal v.iarrants and signal progression.
Analyze potential changes in accidents and safety
considerations.
- Perform v:ii th/wi thou analyses to evaluate the need
for selected accesses to this property.
II. EXISTING CONDITIONS
The location of Harmony Plaza is s•hovin in Figure 1. it
is important that .a. thorough understanding of the existing
conditions be presented.
ILand Use
Land uses in the area are primarily either vacant or
commercial. Commercial development and vacant land exists to
the east (a.cros.s. College Avenue), south (-Across Harmony.
Road). and viest (across. Mason Street) of Harmony Plaza. A
1 ov.l intense warehousing use and vacant land are to the north
of this site. Commercial uses are proposed for the current
va.can t land north of the site. Land in the area is
essentially flat. The center of Fort Col 1 i ns 1 i es to the
' north of Harmony Plaza.
IRoad=_
The primary streets near Harmony Plaza are shown in
Figure 2. Harmony- Poad is south of Harmony Plaza. It is an
east-v)es.t street designated as a major arterial on the Fort
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SITE LOCATION FIGURE 1
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I PRIMARY STREETS FIGURE 2
1-1
i
1
1
Col 1 i ns Master Street Plan. It has recently been constructed
u,test of College Avenue to a four lane cross section with
center turn lanes. mouth of Harmony Plazas, the viest approach
to the College./Harmony intersection has been vi i dened to
prov i de adequate georne tr i cs for the short range future . East
of the intersection, Harmony Road has a four lane urban cross
_section. The expected speed limit will be 35 mph. Sight
distance is generally not a problem along Harmony Road.
Currently, in the immediate vicinity of Harmony Plaza.,
signals exist at College Avenue and Mason Street. A signal
at the Harmony/'Mason inter -section has recently been
installed. In the long range future, Harmony Road is
expected to be -a six lane street according to the Fort
Col 1 i n_• t-la.ster• Street Plan. The nearest other signal along
Harmony Road is. at Lema:.: Avenue to the east (one mile).
College Avenue borders Harmony Plaza on the east. It is
•a. north -south _street designated :_ks a. major arterial on the
Fort Col 1 i n_. Master Street Plan. In this area, College
Avenue ha.s a six lane cross section vii th a center turn lane.
The north and south legs of the College./Harmony inter -section
have been changed to provide additional lanes in the
i n tersec t i on i t=_.e 1 f . [lost of this has been done i,.i i th respect
to the Arbor Pla.za development on the southviest corner. The
existing speed limit is 40 mph. Signals currently exist at
the Col 1 ege:,•Harmony inter -section adjacent to this site and at
a. number of intersections north of the site. No signal
currently exists south of this site.
Mason Street has recently been constructed from the
Target Store to Harmony Road and through Arbor F'1 aza to
College Avenue. It is approximately 40 feet t,.iide north of
Harmony Road. It provides one travel lane in each direction
and a center turn lane at appropriate locations. South of
Harmony Read, Mason Street is 50 feet ixiide and wi 1 l be
striped to serve the land uses t,ai th i n Arbor PI aza. Mason
Street is designated as. a minor ar•+_er• i al on the Fort C:ol 1 i n_.
Master Street Plan. It serves. as a recirculation street for
the properties 1:,,ih i ch are along College Avenue.
Existing Traffic
Dail traffic floc.%, is __.hov)n in
machine counted volumes conducted by
of Hi ghv,;_k s in 15-B.3 and by the City
Peak hour turning movements obtained
.also shov)n in F i qure .3. Raw tr•a.ff i s
in Appendix A.
Figure 3. These are
the Colorado Department
of Fort Collin in 1 5'8? .
in t1ovember 15187 are
count data is provided
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Z � rz 0
W
O
a O
� V
�o
0
m 50/59 4650
06,//508 0987) 1571367
1-8s//04,- 1�.X-1-31130a
—� 08/44 /Z9//35 f -
4750 24!/ZBI� HARMONY M O N Y l38/ZOS i /595&
(/997) - I 0983)
' 35/39 �� 8/ 3 3 /05/80 N N -a
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M 0,
LEGEND
NOON/PM
' RECENT TRAFFIC COUNTS FIGURE 3
r\
U
Existing Operation
'
Since much of this area
is developing, many of the
streets and land uses are
not completed. The only tt;ao
intersect ions which could
be evaluated are Col l ege/ Harmony
and Ha.r•mony1/t--1a.son . These
intersections viere evaluated as
signal controlled intersections
with existing geometries
using the volumes shovin in
Figure 3. The peak hour operation
i s. shovin in T.a.bl e 1 . The
Appendix B. Appendix C describes
calculation forms are provided in
level of service for
__. i gnal i zed and un=_. i gnal i zed
intersections. from the 1985
H i c4hi:d-a-,v C:ap.a.c i ty Manual .
During peak hours, delays are
minimal on al 1 approaches
and the operation is considered to
be acceptable.
III. PROPOSED DEVELOPMENT
Harmony Plaza is a. proposed mixed use commercial
development located at the intersection of College Avenue and
Harmony Road in Fort Col l i ns. Figure 4 shoixis a schematic of
the site plan of Harmony Plaza indicating the uses shot:,.In in
1 Table 2, Trip Generation. The short range analysis (1^= 5)
included full development 1x1i th a 3 percent per year increase
in existing traffic. The long range analysis_. (2010) included
full site development with the traffic volumes indicated in
the FJorth Front Range Corridor Study.
I
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
t:j.a.s. prepared by the Ins.t.itute of Transportation Engineers in
15'76, updated in 1 '7'5:3, .a.nd via.s used to project trips that.
vlou 1 d be generated by the proposed uses at this site. Table
2 s.hov.!s the expected trip generation on a daily and peak hour
basis.
'
P•Jo adjustments vaer•e made for transit or rides -haring.
Therefore, the trip generation can be considered
conservatively high.
Trip Distribution
Tt:,.!o directional distributions of the generated trips
vier•e determined for Harmony Plaza. Distributions from the
commercial uses used population as the attraction variable in
the gra.v i ty model. Future year (1995 and 2010) data was
obtained from information supplied by the Fort C:ol 1 i ns.
Planning Department. For the short range (1995) analysis,
0
Table 1
1987 Peak Hour Intersection Operation
Intersection
CollegeyHarmonx
Harmony: Mason
Land Use
MEDonald`s - 3.5 RSF
Sit Down Restaurant -
8.O RSF
C-Stone
Gas
Retail - 8.2 RSF
Grease Monkey
Total
Noon PM
B (0.57) D (0.78)
A (0.16) A (0.25)
Table 2
Trip G■n■ration
Daly
Noon
Peak
P.M.
Peak
Trips
Trips
Trips
Trips
Trips
in
out
in
out
2400
154
144
76
62
778
52
44
37
!S
1125
54
54
54
54
1064
43
48
58
58
2OO
to
10
10
10
5567
S!a
295
235
202
•
KENSINGTON
SIT DOWN
RESTAURANT
AUTO
RETAIL
C-STORE
GAS
FAST FOOD
RESTAURANT
J �� I
HARMONY
SITE PLAN SCHEMATIC
4
N
FIGURE 4
•
J
the distribution is s.hovin in Figure 5; and for the long range
�2010) analysis, the distribution is shov)n in Figure 6.
Several land use generators such as shopping centers,
drive-in (fast food) restaurant=_., service stations,
conven i ence markets., and other support ser•v ices (banks, etc . ?
capture trips from the normal tr•aff i c passing -by the site.
For many of these trips, the stop at the site is a secondary
part of a 1 inked trip such as from t,.iork to shopping center to
home. In all of these cases, the dr i vevia.y volumes at the
si to are hi gher- than the actual amount of tr•aff i c added to
the adjacent street system, since some of the site generated
traffic vias al read:r counted in the adjacent street traffic.
H pass -by factor of 257,:?* t,,as applied to the newly generated
trips.
1 The procedure used to account for both pass -by traffic
.and primary dent i notion traffic is as. fol 1 ovis:
- Estimate the trip generation rate as. is. currently done and
determine the total number of trips forecast to occur,
based on the size of the development.
- Estimate the percentage of pass. -by trips, and split the
'
total number of tr• i ps. into tvio component=_., one for pass. -by
trips and one for nek�.i tr• i ps.
- Estimate the trip distributions for the tvio individual
components. The distribution of pass -by trips must
'
reflect the predominant commuting directions on adjacent
and nearby roadway f.a.c i 1 i t i es. Most peak period pass -by:
trips are an inter -mediate 1 i nk in a. tvor•k: trip.
'
- Conduct tvict separate trip assignments, one for pass -by
trips. and one for net;:, trips.. The distribution for pass -by
trips t..a i 1 1 require that trips be subtracted from some
intersection .a.ppro.a.ches and added back in to ethers.
'
Typically, this involve reducing through-r•oa.&.lay
volumes. and i ncreas.i ng certain turning movements..
- Combine the assigned trips to yield the total link
'
loadings., and proceed with capacity analysis as normal 1 y`
done.
'
Pr•o:iection=_.
Traffic
Traff i c projections. for the short range time period i,,jere
obtained by factor- i ng the existing traffic by 103 percent per-
* This. pass -by factor was obtained by averaging pas=_. -by.
'
factors from the fol 1 ovii ng sources:
1. Transportation Engi veer• i nQ Desi cin Standards, City of
Laket:,.iood, June 1955.
3. Development and Application of Trip i Generation Rates,
FHI:JA/LISDOT, January 1985.
3. "A h1e thodol ogy for Consideration of Pass -by Trips in
Traffic Impact Analyses for Shopping Centers," Smith, S. ,
'
ITE Journal, August 1936, Pg. 37.
zo-/�
SITE
HARMONY
0
/50/0
SHORT RANGE TRIP DISTRIBUTION
05%
I
HARMONY
W
ZO%
------------------
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FIGURE 5
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LONG RANGE TRIP DISTRIBUTION FIGURE 6
•
year to obtain the expected
traffic in 1995 given
an average
rate of 1 and devel opment in
is identified as background
the immedi ate area.
traffic vih i ch passes
Th i =_. traff i c
by the site
can bath College and Harmony.
Figure 7 shows the
expected
I'P'5 daily traffic consi der i
ng the site generated
traffic and
the background traffic. These
volumes are comparable
to
those indicated in the hJor th
Front Range Corridor
Study.
' For 2CI+ year projections. (year 2010) , the usual source
for projections is the Traffic F1 oti Map as provided by the
Ci ty. Hot!ie er•, the l ast Traff i c Fl ow Flap prov i des
'pr•o.j ect ions for onl y the year 2000 . Therefore, an estimation vlas made of tra.ff i c in this. area by the year 20I0 using the
1 a t e s t Traff i c F1 otji Flap and the knovil edge of vjhat has been
occurring and what is expected to occur in this area of Fort
t Collins. Information developed for the North Front Range
Corr i dor• Study vias al so u t i 1 i zed i n these project ions. These
daily projections are shot. -in in Figure G.
ITrip Assignment
Trip assignment is.
hovi the generated and distributed
trips are expected to be
loaded on the street system. The
'
assigned trips are the res.ul
tant of the trip distribution
process. Figure shows.
the short range noon peak; hour
'
a._.•=• i gnment and the afternoon
Harmony Plaza generated
peak hour- assignment of the
traffic plus background traffic.
Figure 10 _.hovr_. the long
range peak hour assi gnment of the
Harmony Plaza generated
traffic plus background traffic.
'
These assignments .assume
access driveways at locations
proposed by either the developer
or site planner.
ISignal 1XIarra.nts
As. a. matter of policy, traffic signals. are not installed
at any location unless viarrants are met according to the
Ilanual on Lin i form Traff i s Control Dev i ces. Hot--iever, it is
possible to determine whether traff i c signal viarrants are
' likely to be met based upon estimated ADT and utilizing the
chart andz/or• peak hour- t-iarants shovin in Appendix U. Using
the peak hour traffic volumes shovin in Figure °, it is l i ke l y
that traffic signal warrants v.!i 1 1 be met at the College/
' Kensington Intersection. Traffic should be monitored to
determine vihen or if traffic signal warrants are met. The
viarrant analysis -assumes full turns at the Col 1 ege,•`Kensi ngton
' intersection. Without a signal at this intersection, left
turns from Kensington are at unacceptable operational levels
of service due to the high volumes on College Avenue.
KENSINGTON
3,000
/5, 000
HARMONY
1995 DAILY TRAFFIC
W
311 Km
W
Z3,000
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FIGURE 7
4
KENSINGTON N
3, 000
W
Z
O
p
a
a
W
(A
a
o°
o N
110
-i
J
V
33, 000
HARMONY' o
0 0
o
o � d
2010 DAILY TRAFFIC FIGURE 8
O
N O
m�
/9/9
I
132//8
I F
Z
O
N
a
L73/SB
257/607
/08// 3 2
4�i/!o9
29413-70
44/49
mNo
•
r
n�
NOM.
KENSINGTON
NOM.
QD
4,
m
0
0
M �
N
�N
W
._J
W
J
U
m
N
�
m
� m
288/40l0
/99/490
88/5(n
Ll
/lolc/ 3lc 0
4031007
HARMONY /63//71
(�
1741060
/33//0/
\O�
LEGEND
tom
NOON/PM
1995 PEAK HOUR TRAFFIC
FIGURE 9
i
35/40
L /5/5
r-- 40/ZS
�m
O roN
N N
a
J
KENSINGTON 130///0 1
NOM.
80/90
O
0 0
m�m
N //O//40
465/970F:L/00//loo
/oo//Zo 1
4100/520
/80/0150
�N
N N�
L1301110
/VOM.
60/90
N
O
N
ON
W
�J
W
J
75/45
J
�
000
0
N
\��
635//24,5
HARMONY Z50/300
3001400 -- -�
200//!00
LEGEND
NOON/PM
L-4,50/4,50
31DI71PO
r— ZSO/450
I F
O
O
�NN
N�N
Q
N
2010 PEAK HOUR TRAFFIC FIGURE 10
Signal Progression
Signal progression !,,ias evaluated prior to intersection
operational analysis in order to determine t,,ihether• a. signal
at the Col 1 e core:' Kensington intersection should even be
considered. The State Highway Access Code states that this
analysis is necessary for all future or proposed signals
along a. state h i ght,aa.y. In this area, U.S. 28; is a Category
S h i ght,!—=ky. The anal ysi s r•equ i r•es that progress on be
possible along U.S. 28;' with a desirable bandwidth of 40
percent (minimum 30 percent). A speed of 45 mph or the
posted speed !,,,here less than 45 mph should be used. The
analysis should include signals one mile north and south of
the evaluated signal location. The analyses included in this
report shok,a progression diagrams. from Hor•s.etooth to Harmony
tune m i 1 e) And Drake to Harmony (tt,,to mi 1 es) . Neither include
signals south of Harmony since the nearest antic i pated signal
is. tt to ml e s to the south at Trilby Road. Where the desirable
or minimum bandtili dth cannot be achieved with the existing
signals., then the maximum bandt,ii dth possible is that governed
by the existing signals. Ulhen this occurs, the evaluation
can only compare the existing condition to that vii th the
proposed signal location.
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 vlhich provides
graphical representation of the quality of arterial
on .
progression.
- Printing of a. time —space diagram to show the quality
of progression.
- Optimization of signal offsets for arterial pro-
gr• a s__• i on .
The program inputs are:
- Intersection location
- Cycle length
Phasing
Offs.ets.
- Speed
Any or all of these inputs can be changed iteratively in
achieving the optimal progre=_s i on .
College Avenue data for existing signals to the north of
Harmony Road v)a.s• not Available at the time of these analyses
due to break dou.in of the 'Ci ty's signal computer. Historic
( 1PS6) peak hour traffic counts vlere used to determine the
phasing necessary to accommodate the existing traffic. In
1 i eu of .actual phasing and offset data., this is the most
reasonable means of determining the existing signal phasing.
The eva.l ua.t ion made 1,,l i th and vii thou t a s i gna.1 at
Kensington. The signal progression on College Avenue v:as•
anal Xzed Cased upon the fol 1 ovii ng criteria:
- Cycle length of 120-1.30 seconds (as determined by
1 5'B6 progression analyses for the City of Fort
Posted speed of 40 mph.
- [1a.inI ine (Col lege Avenue) G/C Patio
Drake G,, C = 0.46 Off Peak, G/C = 0.55 PH Peak
Harvard G. C = 0.82 Off Peak, G/C = 0.82 PM Peaty:
Sv: allot,., G/C = 0.70 Off Peak, G/C = 0.75 P11 Peak:
Foot h i 1 1 s G-'C = 0 .65 Of f Peak , G/C = 0 .63 PM Pe a.k:
Monroe G.:'C = 0.67 Off Peak, G,/C = 0.55 PM Peak
1
Horsetooth GiC = 0.40 Off Peak, G/C = 0.47 PM Peak
Boardwalk G/C: = 0 . 7 Off Peak, G/C = 0 . ?? PM Peak
Troutman G/C = 0 . 7? Off Peak.. G/C = 0.82 PM Peak
Kensington G/C = 100 no signal, G/C = 0.80 with
si final
Harmony, G/r: = 0 .48 Off Peak , G/C = 0.56 PM Peak
- Green time on the cross street is greater than the
pedestr i an crossing time of the mai nl ine at 4 feet
per second.
- Achieve the largest bandwidth possible along College.
In accordance vai th the State Highviay Access Code, the
posted speed of 40 mph was used. An off peak cycle length of
120 seconds and a PM cycle length of 130 seconds viere used in
these analyses..
Based upon traffic count data, a balanced (equal)
bandwidth is required for the off peak signal progression.
Page 1 of Appendi>, E shows the one mile, off peak progression
analysis v:ii th no signal at Kensington. The through bandwidth
is 27 seconds in each direction or 22 percent. This is under
the minimum al 1 ovaabl e bandv,li dth for a Category 3 Hi ghv,lay in
the State Hi ghv.iay Access Code. Page 2 in Appendix E shovis
the one mile, off peak progression analysis v,1 i th a signal at
Kensington. The through bandwidth is 27 seconds in ea.ch
direction or 22 percent. Therefore, there is no deteriora-
tion of the through bandvji dths on Col l ge Avenue ,-,,hen a signal
is introduced at Kensington. Pages 3 and 4 in Appendix E
shot•j that it is. possible to maintain a 27 second bandwidth in
each direction all the t:,aay to Crake Road. This provides a 22
percent ban&,lidth in each direction vaith or v1ithout a signal
located at Kensington.
In the afternoon peak hour, traffic count data indicates
that the s•outhbound bandvii dth should be wider than the
northbound bandwidth using .an approximate 55' !45% ratio.
Previous progression studies have indicated that a. 130 second
cycle length should be considered. Page I in Appendix F
shows the one mile, PM peak progression analysis with no
signal at Kensington. The through bandwidths are 16 seconds
(12 percent) s.outhbound and 13 seconds. (10 percent)
northbound. These average under the minimum allowable
bandwidth for a Category 3 Highway. Page t in Appendix F
shows one mi 1 e, PM progression analysis with a signal at
Kensington. The through bandwidth in each direction is the
same as if there were no signal at Kensington. Therefore,
there is no deterioration of the through bandwidths on
College Avenue when a. signal is introduced at K.ens. i gn tor, .
Panes 3 and 4 in Appendix F show the bandwidths possible for
the two mile PM peak progressions bath with and without a
signal at Kensington. This analysis re -enforces the
conclusion that the signal at Kensington has little effect on
the progression on College "venue.
Two weeks after the progression studies shown in
Appendices. E and F were completed, the phasing and offset
information was available from the City of Fort Gal 1 i ns. The
existing patterns were run for the off peak (noon) and
afternoon peak using the same progression analysis program.
1
Conversations with Fart C:ol l i ns. Traffic Staff indicated that
c a
the actual speed n College Avenue was generally less than
the posted 40 mph. Therefore, progression runs were
conducted at 40 mph, 35 mph, and 30 mph, The progression
1
runs between Drake and Harmony for the off peak are shown on
pages 1, 2, and 3 of Appendix G and for the afternoon peak
are shown on pages 4, 5, and 6 of Appendix G. The
progression analyses run in 1?86 did not include Drake Road.
This is the reason why the bandwidths shown in Appendix G are
significantly different than that shown in the 1936 runs.
Appendix H shoos the off peak (pages. 1, 2, and .3) and
afternoon peak: (pages 4, 5, and 6) progression runs using the
existing phasing with adjusted offsets.. As with the
progression runs shown in Appendices. E and F, a signal at
Kensington Drive has little effect on the progression on
College Avenue.
The above progression analyses are presented to show
that signals can fit on College Avenue. Design progression
analysis must be conducted on a regular basis reflecting
change in land use, speed, and other variables.
The location of a. signal approximately 500-600 feet_ from
a major signalized intersection, sometimes referred to as a.
"slave-1 i ght ," is a. concept which has been recommended in the
"Access Control Demonstration Project" prepared for the
Colorado Department. of Highways, District 6. it is a method
of providing access to corner properties located at the
intersections of major arterial streets.. It has been
implemented in the City of Lakewood. The Lakewood Traffic
Engineering Department was contacted to gain some insight
'
with regard to their experience with this concept. The
following comments were made:
I
J
I
- The access paint proposed for si gnal i zat i on must have
much 1 ot,.jer traffic k-. of umes vlhen compared to the major street.
A "rule of thumb" ratio of greent ime is 1/3 versus 2/3.
- The left -turn lane storage requirements on the major
street at the ar•ter• i al/a.rter i al intersection take precedence
over the location of a signal at the access..
- The -access signal should have as few pha.s.es as
possible. A tt&lo or three phase signal seems to tt,lork best. A
full eight phase signal is unacceptable.
- At the intersection of tv!a arterials, it i
.a.cceptabl e to introduce signals at the accesses on tt:-•io legs,
but not on all four legs..
The "s-lave light" concept has been implemented in
Lakev,jood on tt;.!o ad.i actin t 1 egs at the t,ladsv,jor• th./Jetae 1 1
intersection. t0ads•v!orth Boulevard is a. six lane arterial
k,,1 h i c h is also State H i g h tf,j a y 1 21 . J e t,! e l l Avenue is a. four
1 an ar•ter• i al The Lakeviood Tra+f i c Engi veer i ng Department
stated that these signals have been performing
sat i sfactor• i 1 y, sery i ng the adjacent 1 and uses, and not
negatively impacting either Wadsvjorth Boulevard or Jewell
Avenue.
The Wa.dst.,.jor• t h. `Jev.ie 1 1 location vjou l d be similar to t h e
Cal 1 ege/Har•mony intersection in Fort C:ol l i ns.. Both College
Avenue and Harmony Road are major arterials v!ith projected
traffic volumes similar to that projected for t,ladstAjorth
Boulevard and Jevje 1 1 Avenue. The existing signal at the
Harmony/Mason inter -section (located 550 feet viest of College
Avenue) and the proposed College/Kensington signal (located
530 feet north of Harmony Road) are on adjacent legs of a
major s i final i zed inter -section. Based upon the preceedi ng
progression analyses, the operational and geometric analyses
prov i ded later in this report, and the accep+_abi 1 i ty of this.
concept in the State of Colorado, it is recommended that the
" slave 1 i gh t" concept be considered at this location. Final
determination is subject to more refined "design level"
studies.
Operations Analysis
Capacity analyses tjere performed on key intersections
v,l i th i n and adjacent to Harmony Plaza. The operations
analyses t,,iere conducted and discussed below as indicated on
the site plan for the short range (1995) analysis. This
includes a signal at the College/Kensington intersection and
right-i n:, r• i gh t-out on both College and Harmony. The long
range (cCi1Ct) analysis discusses other options available, such
as no signal at the College/Kensington intersection, since it
is at the long range level of traffic that geometric and
1
9
J
I
1
rl
i�
i I
I
operational requirements wi 1 1 be at the maximum. The
philosophy used here is that, if the traffic operations work:
for the long range condition, it can work for the short range
condition. Also, the evaluation of the proposed right-
in/right-out on both College and Harmony are provided in a
separate section of this report.
Using the traffic volumes shown in Figure and the
existing geome tr• i cs•, the intersections operate in the short
range condition as indicated in Table i. Calculation forms
for these analyses are provided in Appendix I. The
College/Harmony intersection wi 1 1 operate at level of service
E during the afternoon peak hour with the existing
geometr i cs.. Increasing the geometry for specific movements
will improve the operation of the intersection during the
afternoon peak hour. These geometric improvements and
corresponding level of service are also indicated in Table 3.
Adding a second southbound left -turn lane and a westbound
right -turn lane would improve the afternoon peak hour
operation to level of service D (0 .30) . This is marginally
unacceptable, but m.a.y be allowed since it is a temporary
short range condition. Adding an eastbound right -turn lane
to Harmony with the above improvements would improve the
afternoon peak: hour operation to level of service D (0.77).
This is very close to the existing afternoon peak hour
operation at this intersection.
At the Harmony/Mason intersection, the existing two
phase signal will operate acceptably, except that the left
turns may not a1w.a.y's clear in a given cycle. Introduction of
relatively short left -turn phases for both Harmony and Mason
will clear the left turns and still maintain acceptable
operation overall. At the College/Kensington intersection, a
two phase signal will operate acceptably, except that the
left turns may not always clear on a. given cycle.
Introduction of relatively short left -turn phases for both
College and Kensington will clear the left turns and still
maintain acceptable operation overal 1 . The short range
geome tr• i cs are shown in Figure 11.
Using the traffic volumes shown in Figure 10 and
recommended geometrics, the intersections operate in the long
range condition as indicated in Table 4. Calculation forms
for these analyses are provided in Appendix J. As signalized
intersections, the College/Harmony and Harmony/Mason
intersections operate acceptably with improved geometric=_• and
signal phase improvements.. The recommended/required long
ranee geome tr• i cs• are shown schematically in Figure 12.
At the College/Kensington intersection, a number of
access options. exist. The "South College Properties Flan"
indicates that right-in/right-out/left-in access can/should
be provided at public street intersections which are not
signalized. Critical to providing this is that the
10
Table 3
1995 Peak Hour Intersection Operation
Intersection
Noon
PM
College/Harmony
1987/1988 Geometrics
C
(0.66)
E
(0.90)
2 SBLT
A
(0.52)
D
(0.80)
2 SBLT, 1 EBRT
A
(0.48)
D
(0.77)
College/Kensington
2 Phase
A
(0.35)
A
(0.44)
4 Phase
A
(0.50)
B
(0.59)
Harmony/Mason
2 Phase
A
(0.18)
A
0.29)
4 Phase
A
(0.28)
A
(0.42)
Mason/Kensington
RT Kensington
A
A
LT Kensington
A
A
LT Mason
A
A
Mason/Access
RT/LT Access
A
A
LT Mason
A
A
College Right Out
A
B
Harmony Right Out
A
A
1
F�
I
11
I
L
I SHORT RANGE (1995) GEOMETRICS FIGURE 11
Table 4
2010 Peaty; Hour Intersection Operation
Inter_.ect ion
Noon
Pht
College/Harmon,:
B (0.58)
D (0.83)
College/Kensington
B (0.57)
C (0.66)
Harmony/Hason
A (0.47)
C (0.76)
Mason/Kensington
RT Kensington
A
A
LT Kensington
A
C
LT Mason
A
A
Mason/Access
RT/LT Access
A
C
LT Mason
A
A
College Right Out
B
C
Harmony Right Out
A
A
I
1
I
I
1
LONG RANGE (2010) GEOMETRICS FIGURE 12
C]
1
1
1
1
gec ume tr• i cs. can be accommodated in the _•pace available. The
left -turn lane requirements at the major intersection, in
th i =_. case , the Cal 1 ege:'H.a.r•mony inter -sect ion, must be
satisfied first. The second option Available is signa.liza-
tion of this intersection.
The southbound College Avenue loft -turn lane
requirements at Harmony Road Are 430-570 feet (Appendix K) .
In order to provide anti, median break at Kensington, a double
left -turn lane tot.a.l l i ng 450 feet is possible. This Is
vi i th i n the range indicated above. The storage requirements.
for the left -in on Col 1 ege Avenue At Kensington is a. function
of the turning volume and the opposing traffic on southbound
College. Since College Avenue does/tili 1 1 have signal
progression, the -Analysis of the operation and geometr• i cs
should consider this. If it is assumed that 60 percent of
the opposing traffic (southbound) on College occurs in
platoons, a.nd the left -turning tr•.aff i s Arrives similarly,
then a situation exists that a. portion of the time no left -
turns. are possible due to the arrival of a southbound
platoon and a portion of the time left turns are possible
related to the gaps Available in the opposing traffic. Using
a storage requirement of tvio vehicles (45 feet) during the
time tahen no turns .Are possible and Applying the Har•me 1 i nk.
Curves (Appendix L) to the r•andon turns (100 feet for the
Afternoon peak tra.ff i c), .a. total of 145 feet of northbound
loft -turn lane is. required at Kensington. This length can be
.Accommodated in the space available given the Aforementioned
left -turn requirement=_. at Harmony Road. Figure 13-A shotis a
design for the right-in/right-out/left-in movements. at the
Col 1 ege,P•k.ensi ngton intersection.
I,Ji th =.i gnat i zat i on at the College/Kensington
intersection, geomet_r•ics and operation of the signal itself
must be considered. The southbound loft -turn requirements on
College Avenue at Harmony Road indicated above remain the
Same. The available 450 feet falls Lii th i n the Acceptable
range . Uli th a signal at the Col 1 ege'.-,'Kensington intersection,
the 1enoth of a northbound loft -turn lane is. 140-180 feet as
determined from the nomograph shot:in in Appendix K. This
length (use 160 feet) can also fit into the space avai l a.bl e.
Figure 1 3-B shot. -is a design for a signalized College/
Kensi noton intersection. From an operations point of view,
acceptable level of ser-.: ice QJoon -B, PM - C? is attained
vji th a four phase si gna.l . This, of course, assume=_• that
k:.ens i noton will continue on the east side of College. The
progression Analyses shovied that. A signal with a 80/•20 phase
=.pl i t has no effect on the bandwidth on College Avenue.
Actually, the College Avenue red phase can be increased to As
much as 35 percent and still have no effect on the College
Avenue bandvi i dth . This 35 percent would a.l l ovi for a left -
turn phase on College, a left -turn phase on Kensington, and a
through/right phase on Kensington. LJh i 1 e not necessary to
achieve acceptable operation at the College/Kensington
11
J
RIGHT-IN/RIGHT-OUT
HARMONY
'w
Iw
IJ
COLLEGE AVENUE GEOMETRICS
WITH RIGHT -IN / RIGHT -OUT /
LEFT -IN ACCESS AT KENSINGTON
FIGURE 13 - A
J
RIGHT-IN/RIGHT-OUT
HARMONY
COLLEGE AVENUE GEOMETRICS
WITH SIGNAL AT KENSINGTON
FIGURE 13-B
1]
F
n
intersection, consideration should be given to providing an
exclusive sou thbound r- i gh t-tur-n lane on College appr•oa.ch i ng
Kensington. The turn i no volume exceeds the v.iarrant for this
lane in the State H i ghlxiay Access Code. This. lane w i I I remove
right -turning vehicles from the through traffic lane
pr-ov i di rig a. much _•a.fer si tuat ion, i ncreased =_•tr-eet capac i ty,
and improved site access..
At the Harmony/Mason signalized intersection, four phase
oper-a.t i on v.l i l l a__••=_.ijr•e that the conflicting left -turn
movements on both Mason and Harmony clear in a given cycle.
Given the volumes anticipated at this intersection, 45-50
percent of the cycle can be devoted to Harmony Road through
green. Operation at this. intersection is expected to be
.acceptable.
A r- i gh t- i nr•r- i gh t-out access has been proposed on Col 1 ege
Avenue, approximately 270 feet north of cent.erl ine of
Harmony, and on Harmony Road, appr-ox imatel y 320 feet viest of
the centerline of College. Loth of these accesses require
r i oh t.-turn deceleration lanes in order, to assure safe,
efficient operation. The College Avenue right-i n/r- i gh t-out.
can be de=_• i gned to allow a 15 mph turn. If this is done, a.
deceleration length of 295 feet is requ i r-ed according to the
State Highviay Access. Code. This length will extend the
decel er•a.t i on lane through the Kensington intersection. it
is, they-efor•e, recommended that the dece 1 er•at i on lane for- the
right-i nr•r i ciht-out access be continuous from Kensington to
the south. This. type of con t i r.ijou=_• r• i gh t-turn lane is. common
on major ar ter• i .a.l =• vi i th the combination of high through
volumes and high r i gh t-turning volumes. Since the s•outhbound
r• i gh t-turn lane at the Col l ege/Har-mony intersection is
recommended as• shot:,Jn in Figure 12, the right -turn lane should
be continuous. to Harmony Road.
If the Harmon:.,, Road r• i gh t- i n.:'r• i gh t-out •access is
designed to a.l 1 ovi a. 15 mph turn, a. decel era.t i on lane length
of 235 feet is. required according to the State Hi gtwlay Access
Code . Hotxiever, , Harmony Road, vest of College Avenue is not a
State Hi ghvlay and its location with respect to the College/
Harmony signal could a.11ow some fIexibi 1 i ty v)i th repect to
its desicin. According to A Policy on Geometric Design cf
Highways and Streets-, AA`=;HTO, 1984, pg. 874,
"The 1 eng_ th of the ---tux i 1 i •ar-y 1 ane=_• for turn i rig
vehicles consists of three components : (1 )
dece 1 era.t i � �n length , ( 2) stor-age length, and
<3) entering taper. Desirably, the total length
of the aux i 1 i ar•y 1 .ane should be the sum of the
length for these three components. Common
prat t i ce , hot,,iever , i s. to .accept a moderate amoun t
of decel er•at i on v.ji thin the through lanes and to
consider- the taper as a part of the deceleration
length. t.0here intersections occur as frequently
1�
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it
as four per mi 1 e , it is customary to forego most
of the deceleration length and to provide only
the storage length plus taper."
According to the deceleration distance nomograph, from
AASHTO, Pg. 36 and shown in Appendix M, a passenger vehicle
can comfortably brake from 35 mph to 15 mph in 180 feet. it
is, therefore, recommended that a right -turn lane/taper
combination totalling 200 feet should be provided on Harmony
Road approaching this access. This !jai 1 1 remove decelerating
vehicles from the through traffic lane on Harmony Road,
providing safe, efficient operation. This wi 1 1 also provide
a "pedestrian bulb" at the College/Harmony intersection which
wi 1 1 shorten the walk time across Harmony Road. The
"pedestrian bulb" would also provide better lane alignment
for vehicles westbound on Harmony Road. A right -turn
acceleration lane is not recommended at this access.
Both
of the right-in/right-out accesses wi 1 1 be
evaluated
in a "wi th;'wi thout" analysis in
Chapter IV. The
analyses
provided above show the access as
proposed by the
developer
of the property.
The
two intersections to Mason (the
Mason/Kensington
intersection
and a. driveway access located
280 feet north of
H"rmonyl
will operate acceptably with stop
sign control.
Accident
Analysis
The
recommended control devices and
geomet.rics should
minimize
vehicular conflicts and maximize
vehicle separation.
Therefore,
the accident rate should be at
its minimum for a
typical urban
condition.
IIV. ACCESS ANALYSIS
I f a development plan proposes private driveway accesses.
to arterial streets, the City of Fort_ C:ol 1 i ns requires a
'
"with and without" analysis. The purpose of this analysis is
to _.how the change of operation to nearby intersections and
streets both with the proposed access and without the
proposed access. The Harmony Plaza site plan proposes two
driveway acce=ses to arterial streets. These are a. right -in.,''
right -out access to College and a. right-in/right-out access
to Harmony Road. The earlier analyses in Chapter III shot,,,
the expected traffic volumes and operation with these two
right-in/right-out accesses. The long range peak hour
traffic volumes are shown in Figure 10 and the long range
peak hour operation at intersections is shown in Table 4.
Figure 14 shows the long range peak: hour traffic volumes
'
without the two right-in/right-out accesses. Elimination of
1 13
•
�O
mN
Op
35/40
N
Ct O
ON
BO/5O
Nm�
\ � M
oop
JIB
/DO//ZO
46DI500
/BO/Z50
0/5/ZO5
4 Z 5/94,i
�- /00//60
KENSINGTON
HARMONY
2010 PEAK HOUR TRAFFIC
NO RIGHT-IN/RIGHT-OUT
ON COLLEGE OR HARMONY
No-
� N
O
m rM m /30///O
/55//35
/30///o l F
NOM.
l55//35 Oo p
0� O
�O0%
N
,-so 1300 1
300/400
000//60
L350/4So
3101760
� 05 014,50
I I F
O
0
pN0
� � N
O
Na
IMi
FIGURE 14
either access has the most impact on the adjacent inter-
section, that is, the College Avenue access is related to the
College/Kensington intersection and the Harmony Road access
is related to the Harmony/Mason intersection. Volumes at the
College/Harmony intersection are not 1 i ke 1 y to vary much with
or without the right-in/right-out accesses.
Table 5 shows. the long range peak hour operation at the
key intersection, without the two right-in/eight-out
1
accesses. Calculation forms for these analyses are provided
in Appendix N. It can be seen that the operation at both the
College/Kensington and Harmony/Mason intersections
deteriorates from that reflected in Table 4. More
significant than the deterioration in operation is the
additional time of the cycle that must be devoted to the non -
through movements of the arterial streets.. The shortening of
the through green phase at each intersection can begin to
affect the main street progression.
If the Coll ege/Kensington intersection is not
signalized, the movements are reduced to right-in/right-out/
left -in. Providing the additional right-in/right-out a.cces.s
south of Kensington will increase the number of through
vehicles on College Avenue. No right-in/right-out access
increases the number of s.outhbound College right -turns at
Kensington. These right turns slightly reduce the number of
vehicles in the right hand through lane. The effect on
operation will be minimal.
Based upon the analyses reflected in this report, the
following recommendations are made with regard to the r• i gh t-
i n/r• i ght-out accesses:
r-
The access. to Harmony Road is recommended since it
has a positive effect on the operation at the Harmony/Mason
signalized intersection. It is also possible to design an
adequate right -turn deceleration lane for this access.
- The access to College Avenue is recommended if the
College/Kensington intersection is signalized, since it has a
positive effect on the operation at the signalized inter-
section. This improved operation has the additional positive
effect of providing the longest possible through bandwidth on
'
College Avenue.
- Without a. signal at the Col lege/Kensington inter-
section, the effect of the right-in/right-out access is
minimal and, as such, no recommendation can be made.
I V . CONCLUSIONS
This study assessed the impacts. of Harmony Plaza on the
short range (1995) and long range (2010) street system in the
1 14
Table 5
2010 Peak Hour Intersection Operation
with no Right-in/Right-out on College and Harmony
Intersection Noon E
-11
College/Harmony 8 (0.58) D (0.88)
College/Kensington L (0.63) C: (0.69)
Harmony/Mason A (0.50) D< 0 .78 )
Ma.=.on/Kensi nGton
RT Kensington
A A
LT Kensington
A C
LT Mason
A A
Mason/Access
RT/LT Access
B G
LT Mason
A A
1 0 0
1
11
F
u
11
vicinity of the proposed development. As a result of this
anal w's.i s., the fol 1 caw i ng i conc 1 uded:
- The development of Harmony Plaza is feasible from a.
traffic engineering standpoint. At full development as
proposed, approximately 5500 trip ends t&i i 1 1 be generated at
this site daily. Also considered in this a.na.ly's.is is the
property to the north t-.h i ch is expected to generate an
additional 3500 tr• i p ends per day.
- Ex i st i ng operat i on at the Col 1 ege/H._.rmony and
Harmony ,/Mas.on intersections are acceptable vi i th existing
geome tr i cs..
- By 1'='5'5, given ful l development of Phase I of Harmony
Plaza and an increase in background traffic, the signalized
i n ter -sec t i can of Col l ege and Harmony t,a i l l operate accep tabl y
t:,ii th some geometr i c improvements. The Har•mony'/Hason and
Col 1 ege/Kensi ngton intersections. 4-,ii 1 1 operate acceptably (.,•)i th
signal control. I,ai th stop sign control, the Mason Street
intersections. should operate at acceptable levels of service
during peak hours.
- By 2010, the College/Harmony inter -section t,i i 1 1
operate a.cceptabl"' at the noon peak and unacceptably in the
a.f ternoon peak . However, the geome tr i cs shown/recommended on
Harmony Road are not at its full six lane t:!i dth . The
unacceptable operation is likely to occur for only a short
time on an average day. It is questionable t,,lhether the vior•st
case peak hour should be made acceptable. There is. a point
of diminishing returns for, the investment in the street. If
the full six tone i:,,ii dth of Harmony Road is considered in this
inter -section, acceptable operation during the afternoon peak
hour is attainable. t4i th stop sign control, the Mason Street
inter -sections t,,1i 1 1 operate acceptably. With signals at the
College/Kensington or Harmony/Mason intersections, acceptabl e
operation t,,li 1 1 occur.
- Sicinals. at the College/Kensington inter -section can
fit into an existing progression band on College Avenue. The
signal does not reduce the bandwidth along College Avenue.
The bandwidth is gover•ned by other signals along College
Avenue.
- The proposed stop sign controlled limited turn
dr i vei,:ja.y accesses to both College and Harmony t,,0 1 1 operate
acceptably. A right -turn auxiliary (deceleration) lane is
traa.rran ted at each. This. right -turn lane t,iou 1 d remove
vehicles. from the through traffic stream providing a safer
condition. The fol 1 ot,.!i ng recommendat i ons are made t,,ii th
regard to these right-in/right-out accesses:
- The access to Harmony Road is recommended since it
has a positive effect on the operation at the
1
15
Harmon; .,"11ason =_. i Gna 1 i zed i n ter•=_.ec t i on . It is also
possible to design an adequate right -turn
deceleration lane for this Access.
The access to College Avenue is recommended if the
Col 1 ege: Kensington inter -section is s.i gnal i zed, since
it has .a positive effect on the operation at the
signalized intersection. Th i =_• improved operation has
the additional positive effect of providing the
longest possible through ba.ndv,ii dth on College Avenue.
l�Ji thout a. signal at the College/Kensington inter-
section, the effect of the right-in./right-out access
is minimal and, as such, no recommend.a.t i on can be
made .
- 1.0ith the recommended control geometries, the Accident
rate should be at an acceptable level for, typical urban
conditions.
16