HomeMy WebLinkAbout1.24 Traffic Report - Cerise Mine Operating RevisionsTel: 303-792-2450 P.O. Box 630027
EUGENE G. COPPOLA P.E., PTOE
Fax: 303-792-5990 Littleton, CO 80163-0027
May 12, 2014
Ben Langenfeld
Greg Lewicki & Associates
11541 Warrington Ct.
Parker, CO 80138
RE: Cerise Mine Operating Revisions
Garfield County, CO
Ben:
As requested, I have reviewed the current plan for the Cerise mine (Cerise) and com-
pared it to the previous plan evaluated in the 2012 Traffic Impact Study (TIS) which
was approved by the County and CDOT. The review addressed two primary areas:
1. The applicability of the TIS to the current development plan for Cerise, and
2. The adequacy of improvements already built or those in the process of being
built based on the earlier plan.
Key criteria for each of the above indicated areas of investigation are noted below and
are followed by an assessment of the validity and relevance of each criterion to the
current plan.
1. 2012 TRAFFIC IMPACT STUDY
SITE TRAFFIC
Site traffic related to the approved plan and the current plan is as follows:
Traffic Activity
Approved Plan
Proposed Plan
Change
Asphalt & Aggregate Trucks
250/day
200/day (1)
-20%
Concrete Trucks
75/day
42/day (2)
-44%
Import Trucks
5/day
5/day
0
Employees
45/day
15/day
-67%
Miscellaneous
10/day
10/day
0
(1) Aggregate only
(2) Aggregate hauled to Powers Pit
As indicated, site generated truck traffic will decrease by 83 trucks per day, represent-
ing a decrease of about 25%. The number of employees will be reduced from 45 to 15
or about a 67% reduction. The overall decrease in site traffic is considered meaningful.
SITE ACCESS
Site access will remain unchanged from the earlier plan for the Cerise mine. According-
ly, the access location on Crystal Springs Road (CR 103) has been previously approved
by the County.
SITE TRAFFIC DISTRIBUTIONS
Traffic distributions expected with the earlier plan split truck traffic equally east and
west of Crystal Springs Road on SH 82. This will remain essentially the same with the
current plan. Employee trips are also expected to reflect the distributions used for the
earlier plan.
PEAK HOURS
Site peak hour traffic was added to highway peak hour traffic to approximate worst
case conditions. Consequently, peak traffic is expected to occur at times similar to
those evaluated in the TIS.
BACKGROUND TRAFFIC
Traffic was counted at the SH 82 - Crystal Springs Road intersection in June 2010 as
part of the TIS. This traffic was adjusted upward to reflect future background traffic
consistent with the start of operations in 2012 and the long term horizon some 20
years later. CDOT's published 20 year growth factor of 1.60 was used in this effort.
This growth factor is identical to CDOT's currently published growth factor for this sec-
tion of SH 82.
CDOT was contacted to obtain traffic counts on SH 82 since the earlier study was com-
pleted. Per the study, SH 82 served 17,700 vehicles per day in 2009 based on CDOT's
latest available published data when the TIS was prepared.
Daily traffic on SH 82 since the traffic study was prepared is shown below:
Year
ADT
2010
18,000
2011
16,000
2012
17,000
2013
17,000
As shown, traffic on SH 82 has decreased since the traffic counts used in the TIS were
conducted. Since 2010, traffic has dropped some 51/2% on SH 82 and has remained
below 2010 levels since that time. Accordingly, background traffic used in the TIS may
be somewhat high and therefore, the analyses present a conservative outlook.
OPERATING CONDITIONS
The TIS demonstrated that long term intersection levels of service with Cerise traffic
will be acceptable. With less site traffic and possibly lower background traffic, accepta-
ble and improved operations are expected in the future.
2. IMPROVEMENTS
Per our discussion, the improvements recommended in the TIS have been designed,
approved, and constructed at the SH 82 - Crystal Springs Road intersection with drive-
way improvements currently in process. Major improvements include:
• Improved turning radii at the SH 82 - Crystal Springs Road intersection.
• Improving the southbound to eastbound left turn acceleration lane and the
westbound right turn deceleration lane on SH 82 at Crystal Springs Road to cur-
rent CDOT standards.
• Improving the approach angle of Crystal Springs Road to SH 82 and providing a
southbound left turn lane at this intersection.
• Driveway construction, striping changes and signing enhancements.
The above improvements should be acceptable since they are either speed limit based,
which has not changed, or traffic based, which will be less than anticipated. Conse-
quently, the improvements will serve the combination of site traffic and background
traffic through the long term.
SUMMARY
Based on the above reviews, evaluations, and comparisons, it is concluded that:
1. Site traffic will be some 25% lower than the site traffic evaluated in the April
2012 traffic impact study.
2. Background traffic will likely be less than estimated in the TIS given stable or de-
clining traffic on SH 82 since the TIS was prepared.
3. Long term operating conditions contained in the TIS were determined accepta-
ble; however, with the expected reduction in site traffic and possibly less back-
ground traffic growth, improved operations are anticipated.
4. Recent roadway improvements will be sufficient to serve long term traffic de-
mands including Cerise traffic and are properly designed for the current speed
limit.
5. The traffic impact study for the Cerise mine remains valid and fully addresses
and demonstrates the acceptability of the current plan.
I trust this letter will be sufficient to allow the current plan for Cerise mine to proceed
under the earlier submitted and approved traffic impact study. Please give me a call if
you have any questions or need further assistance.
Sincerely,