HomeMy WebLinkAboutShadow Glen_ITD_2020-10
IDAHO TRANSPORTATION DEPARTMENT
P.O. Box 8028 • Boise, ID 83707-2028
(208) 334-8300 • itd.idaho.gov
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October 2, 2020
Eric Scheck
Hayden Homes
escheck@hayden-homes.com
VIA EMAIL
RE: Shadow Glen Subdivision – ITD Development Condition Memo
Dear Mr. Check,
I really appreciate the work you are doing to help those who are living in this beautiful area of Caldwell, ID. The
Shadow Glen Subdivision Traffic Impact Study (TIS) provided by CR Engineering has been reviewed. The trips generated
by your development adds congestion to US 20/26. ITD is working with the city of Caldwell to enter into an agreement
to collect a proportionate share contribution from each new development for impacts to the State highway system. As
two agencies we will work together to accelerate highway construction on US 20/26 to accommodate new
development growth. ITD values your contribution to the transportation system so we can help keep goods, services
and the public moving efficiently.
ITD determined Shadow Glen Subdivision’s proportionate share contribution to be $373,512 (2.3%). This is based off
the development’s site trips through the intersection of US 20/26 and Middleton Road in comparison to total 2040
traffic volumes. The US 20/26 Corridor plan has identified that the future intersection configuration shall be a half-
continuous flow intersection. Details of the proportionate share calculation are included in the attached ITD Staff
Technical Report.
Thank you again for your partnership. If there are any questions or concerns please don’t hesitate to email me at
Justin.Price@itd.idaho.gov or give me a call at 208-334-8340.
Sincerely,
Justin Price
Justin Price
ITD District 3 Traffic Engineer
Cc:
Deb Root – City of Caldwell
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Staff Technical Report
9/25/2020
10/2/2020 REVISED
Development: Shadow Glen Subdivision
Lead Agency: City of Caldwell
Deb Root
Senior Planner
droot@cityofcaldwell.org
Phone: 208-455-4662
Location: South of US 20/26 at the NE corner of Ward Road and Linden Road.
US 20/26 MP 27.25
Applicant: Eric Scheck
Hayden Homes
escheck@hayden-homes.com
Consultant: Chhang Ream
CR Engineering
181 East 50th Street
Garden City, ID 83714
Rbeckman@whpacific.com
Phone: 208-275-8715
Staff Contact: Erika Bowen
Traffic Technical Engineer
Erika.Bowen@itd.idaho.gov
Phone: 208-265-4312 ext. #7
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Traffic Findings for Consideration
1. Proposed Development
The proposed Shadow Glen Subdivision includes 257 single-family homes, a gym and daycare center. The
expected buildout is 2026.
2. Vicinity Map
3. Trip Generation:
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4. Trip Distribution:
5. Traffic Impact Study
Dated: January 3, 2020
a. Executive Summary
CR Engineering prepared a traffic impact study for the proposed Shadow Glen Subdivision. Below is an
executive summary of the findings as presented by CR Engineering. The following executive summary is not
the opinion of ITD staff. ITD Staff has reviewed the submitted traffic impact study for consistency with ITD
policies and practices and may have additional and/or varied requirements beyond what is noted in the
summary.
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6. ITD Policy Review
a. Proportionate Share Contribution
ITD District 3 has issued Memo 39-Development Proportionate Share Contribution as a means to request
equitable contribution from developers to improve public facilities needed to serve new growth and
development.
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b. Jurisdictional Authority
ITD does not have jurisdictional authority to require improvements from the developer. A formal letter
of request will be sent to the City of Caldwell requesting them to include any mitigation to the State
highway system in their development agreement.
7. Staff Comments Recommendations
Intersection of US 20/26 and Ward Road
The Shadow Glen TIS shows that the intersection of US 20/26 and Ward Road has failing movements and v/c
ratios exceeding 0.90 at 2026 buildout (AM and PM Peak) for specific movements. The overall intersection
operates at a LOS B. Analysis included improvements that are to be constructed by ITD’s project: KN 22165
Smeed to Middleton Widening. See Appendix A. The deficient movements are eastbound left, westbound
left, northbound right and southbound right.
KN 22165 is building out US 20/26 to the ultimate configuration of the US 20/26 corridor. See Strip Map
image below. The eastbound left and westbound left turning movements show a 95th percentile queue
length of 46ft (AM) / 86ft (PM) and 116ft (AM) / 128ft (PM), respectively. The turn bays can accommodate
these storage lengths. See Appendix B and C for details.
Staff does not recommend requesting proportionate share for any mitigation improvements at the
intersection of existing US 29/26 and Ward Road.
Intersection of US-20/26 and Middleton Road
The Shadow Glen TIS shows that the intersection of US 20/26 and Middleton Road has failing movements
and v/c ratios exceeding 0.90 at 2026 buildout (AM and PM Peak) for specific movements. The overall
intersection operates at a LOS D. Analysis included improvements that are to be constructed by ITD’s
project: KN 22165 Smeed to Middleton Widening. See Appendix A. The deficient movements are eastbound
left, southbound left, northbound thru.
KN 22165 is only partially widening the US 20/26 and Middleton Road intersection. ITD estimated the design
and construction costs of a half-continuous flow intersection to be $16,239,692. See attached estimate in
Appendix D.
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2026 Site Traffic (Original TIS Traffic Volumes)
*Per Chhang Ream’s email. ITD shall use 168 PM Peak hour trips through the US 20/26 and Middleton Road
intersection to calculate proportionate share.
AM PM
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2040 Total Traffic (KN 07826…Only PM totals analyzed in study)
Staff recommends the developer pay a total proportionate share of $373,512 (2.3%) towards future CFI
improvements at the intersection of US 20/26 and Middleton Road. Proportionate share needs to be
provided prior to occupancy of the development.
*ITD Staff Recommendations are intended to assure that the proposed development will not place an undue burden
on the existing State Highway system within the vicinity impacted by the proposed development.
** Recommendations included in ITD’s Staff Technical Report along with any development conditions (see associated
Permit Committee Agenda/Minutes) is only valid for the period of one year from the date of the TIS report. ITD
reserves the right to request an updated TIS to reflect current traffic conditions if an approved encroachment
application and/or proportionate share contribution are not obtained/provided within one year.
8. Appendices
Appendix A 2026 Buildout Year Total Traffic
Appendix B 2026 Buildout Ward Road HCM Analysis
Appendix C KN 22165 Ward Road Preliminary Pavement Striping Plans
Appendix D Cost Estimate: Middleton Road and US 20/26 Half-CFI
PM Site = 168 PM Total = 7,343 PM % = 2.3
Proportionate Share for US 20/26 and Middleton Road half-CFI Intersection Improvements
Avg % = 2.3
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Appendix A 2026 Buildout Year Total Traffic
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Appendix B 2026 Buildout Ward Road HCM Analysis
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Appendix C KN 22165 Ward Road Preliminary Pavement Striping Plans
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Appendix D Cost Estimate: Middleton Road and US 20/26 Half-CFI
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