To: Honorable Mayor and Members of Town Council
From: Tony Marusiak, Public Works Project Manager
Title
Resolution Approving the First Amendment to the Town of Castle Rock Services Agreement between Short Elliott Hendrickson Inc., and the Town for the Founders Parkway/Fifth Street/Ridge Road Intersection Improvement Design
Body
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Executive Summary
The purpose of this memo is to obtain approval of an amendment to the contract between the Town and Short Elliott Hendrickson Inc. (SEH), for the design of the Founders Parkway/Fifth Street/Ridge Road Intersection Improvement Design.
The attached resolution (Attachment A) approves the amendment to the contract with SEH. The approved amendment will allow staff to move forward with the design.
History of Past Town Council, Boards & Commissions, or Other Discussions
The original services agreement was presented to the Public Works Commission on May 1, 2017. The Commission unanimously recommended Town Council to approve the resolution. At the May 2, 2017 Town Council meeting, Council unanimously approved the resolution. Staff will present the amendment to the Public Works Commission on February 5, 2018; results will be presented at the Council Meeting.
Discussion
The Town instructed the consultants who submitted design proposals to assume a standard intersection widening in order to compare fees. The selected consultant (SEH) was also required to provide conceptual design alternatives for three intersection control options to be assessed from a cost/benefit perspective. The three options chosen were: standard intersection widening, roundabout, and continuous flow intersection. The attached technical memo (Attachment B) outlines the analysis of each alternative. The following is the recommendation:
After reviewing each of these three options for level of service, cost, and other associated issues, we feel that a roundabout, Alternative 2, would be the preferred alternative for this project.
Alternative 2, the two lane roundabout, operates at the best level of service and has the lowest conceptual cost, and could be expanded to three lanes in the north-south direction to accommodate future buildout.
In general, roundabouts have proven to be safer and more efficient than signalized intersections. A bypass lane will be installed for traffic traveling westbound on State Highway 86 which will alleviate congestion, particularly during the morning rush hour. The attached exhibit (Attachment C) is a conceptual layout of the roundabout.
After the design team determined a roundabout to be the most cost effective and beneficial alternative for the intersection, the scope change required feedback from CDOT which delayed completion. The change in intersection design, along with the time it took to coordinate review meetings to gain CDOT approval, creates the need to update the scope, fee, and design schedule. Currently, the Town has paid out a total of $62,824.61 at the 2017 rates for survey, cost benefit analysis of the intersection alternatives, and conceptual designs. The roundabout design will be paid out at 2018 rates.
The original schedule had the standard intersection widening design to be completed by December 31, 2017. The revised schedule has the roundabout design to be completed by December 31, 2018. The Town’s current five-year CIP has the construction for the project scheduled for 2021.
Budget Impact
The funds necessary for the engineering design have been included in the project’s 2017 budget as stated below.
Fund Account Number Amount
Founders Parkway/Crowfoot Valley 135-3175-431.78-69 $ 340,000
Road/Ridge Road Intersection
Original Council Authorized Contract Amount: $240,195
Proposed Council Authorized Contract Amount: $294,293
SEH has provided an additional cost of $54,098 to complete the project with the scope changed to a roundabout design and the 2018 rate increases for a new “not-to-exceed” services agreement cost of $294,293. The remaining budget will be $45,707.
Staff Recommendation
Staff recommends the Town Council approval of the Resolution as introduced by title.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Attachments
Attachment A: Resolution
Attachment B: Technical Memorandum
Attachment C: Conceptual Layout of Roundabout