HomeMy WebLinkAbout981653.tiff PFELSBURO
rg HOLT
ULLEVIG
engineering paths to transportation solutions
August 14, 1998
Mr. Don Carroll
Weld County Public Works Department
P.O. Box 758
Greeley, Colorado 80632-0758
RE: Beebe Farms Draw Traffic Review
FHU Reference No. 98-161
Dear Mr. Carroll:
We have completed our traffic engineering review of the proposed Beebe Draw Farms PUD
Master Plan and traffic impact study for the development to be located between WCR 32,
WCR 38 and WCR 39, east of Platteville. This letter provides our comments on both the
traffic study (prepared by Matthew J. Delich, P.E., in May 1998), and the plan.
TRAFFIC IMPACT STUDY
In general, the traffic study prepared for Beebe Draw Farms is complete and was prepared
using the most recent trip generation and intersection capacity techniques. Trip distribution
estimates are also reasonable. We do offer the following comments:
• A growth rate of 3 percent per year was assumed in the study to project background
traffic volumes for Phases 1 through 5 (years 2001 through 2006), of Filing 1 . This
growth rate was based upon traffic projections on similar facilities as documented in
the 2015 NFR RTP. We conducted further research in the 2015 UFR RTP, and
determined that a growth rate of 3 percent per year is reasonable.
Additionally, a brief sensitivity analysis was conducted to determine the growth rate
which could occur before operations would drop to LOS D given the recommended
improvements. It was estimated that a background traffic growth rate of between 10
and 15 percent per year could occur before operational analyses at the two relevant
intersections would drop to LOS D by the year 2020. So while a 3 percent annual
growth rate is reasonable, there will be ample reserve capacity for even more growth
given the recommended improvements.
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August 14, 1998
Mr. Don Carroll
Page 2
• No trip generation was documented in the study for the recreational use of Milton
Reservoir or the proposed cross country jumping course. These trips would impact the
collector roadway which bisects Filing 1, as well as its intersection with CR 39.
However, the golf course and residential trip generation were both conservatively
estimated given the remoteness of the site. The golf course trip generation
documented by ITE is indicative of sites which primarily attract external trips; residents
of Beebe Draw Farms will most likely be the primary source of patrons at the golf
course. In addition, the residential trip generation used is for single family detached
homes in urban areas. Trip generation rates for more rural, residential areas tend to be
less because drivers make fewer trips to/from home, making all of their necessary trips
while they are out. Therefore, the conservative trip estimate of the golf course and
residential areas should approximately offset trip estimates associated with the
reservoir and cross country course uses.
The acceleration/deceleration lanes recommended in the study are based upon the current
State Highway Access Code (SHAG), and were found to be moderately conservative. The
following comments summarize our review of these recommendations.
• The recommendation in the report is to build a northbound, right-turn deceleration lane
on CR 39 at the site access during Phase 3, and a southbound, left-turn deceleration
lane on CR 39 at the site access during Phase 5. Since both of these recommendations
are based upon conservative interpretations of the SHAC, it is our recommendation that
the left-turn deceleration lane be built during Phase 3. Left-turns present a greater
safety hazard as they must turn across a lane of on-coming traffic, have the potential
for conflict with traffic turning out of the site access, and pose a greater threat for rear-
end accidents if made from a shared lane.
• Figure 22 of the study depicts an exclusive right-turn lane from southbound CR 39 to
CR 32. The study suggests that construction of the lane be cost-shared based on
traffic loading. This translates into a 65/35 split, with the developer being responsible
for the larger portion. However, this lane would not be necessary if the development
does not occur. As such, there is a basis for requesting 100 percent participation for
the lane.
• Additionally, in Figure 23, the study recommends further construction of turn lanes at
the two relevant intersections for the long term time frame (build out). These
construction costs could also be divided based upon the origin of the traffic entering
each of the intersections. At the intersection of CR 38/CR 39, it is estimated that
approximately 75 percent of the traffic will be generated by the site, and the remaining
25 percent can be attributed to background traffic. Similarly, at the intersection of CR
32/CR 39, it is estimated that approximately 80 percent of the traffic will be generated
by the proposed development, and the remaining 20 percent will be background traffic
volumes. Again, these improvements are not necessary if the development does not
occur and it may be reasonable to request the developer to fund 100 percent of the
improvements on this basis. The traffic study did not offer an improvement phasing
plan for the long term improvements needed at site build out (past Filing 1).
August 14, 1998
Mr. Don Carroll
Page 3
Another consideration is the intersection of US 85/CR 32, approximately 7 miles west of the
proposed development. This intersection is being studied as part of the US 85 Access Control
Plan and is being identified for potential signalization in the future. At build out of the
proposed Beebe Draw Farms development, most of the side-street demand relative to
satisfying the signal warrant at this intersection, would be generated by the development.
Therefore, it may be reasonable for the County to request a financial contribution from the
applicant towards the future signal installation.
PLAN REVIEW
The PUD master plan was also reviewed for meeting general traffic engineering principles.
From observing the plan, only one area of concern was identified, relative to access locations.
A field trip to the proposed site location identified these concerns regarding the proposed site
accesses:
• The main CR 39 access is proposed to be located approximately 1 .5 miles north of CR
32, approximately half way between CR 32 and CR 38. There is an existing dirt access
at approximately this location with a sign identifying it as the future access to the
Beebe Draw Farms development. If the location of the existing dirt access is the exact
location of the proposed future access, there is a sight distance concern looking to the
north, up a slight hill. We suggest that the proposed intersection be evaluated closer
to ensure that proper intersection sight distance will be provided.
• There is a future proposed site access on CR 32, located approximately one-half mile
east of CR 39. Without being able to determine the exact location of this proposed
access, there is concern of adequate sight distance to the west where a slight hill
exists in the existing roadway. This too should be carefully reviewed for adequate
intersection sight distance.
Some other field observations were also made:
• CR 39 and CR 32 are both projected to be built out as collector roadways. The Weld
County Subdivision Ordinance (173E) states that collector roadways should have a
ROW width of approximately 80 feet. It was estimated from the field observations that
these roadways have ROW of between 50 and 60 feet. These widths should be
checked, and additional ROW dedicated as necessary. The County should also consider
requiring construction of one-half a collector roadway along the site's roadway
frontage.
• CR 38 should be paved when access to Beebe Draw Farms is provided onto this road.
August 14, 1998
Mr. Don Carroll
Page 4
If you have any questions, or need additional information, please do not hesitate to call.
Sincerely,
FELSBURG HOLT & ULLEVIG
a- 4 F4
Debra L. Zermuehlen, E.I. Christopher J. Fasching, P.E.
Transportation Engineer Senior Transportation Engineer
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