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HomeMy WebLinkAbout2023-10-23 ACHD Waltman Design Memo Alexis Pickering,President Jim D.Hansen,Vice-President ACHD David McKinney,Commissioner Kent Goldthorpe,Commissioner `� Miranda Gold,Commissioner *... October 18, 2023 To: Ethan Mansfield - Hawkins Companies Becky McKay - Engineering Solutions Subject: Concept Design for Development Mitigation - Meridian Road and Waltman Road Intersection Ethan and Becky, Thank you for submitting the January 2023 memo prepared by Six Mile Engineering which proposed phased alternative improvements at the Meridian Road/Waltman Lane intersection to address the traffic impacts of the proposed Tanner Creek and Meridian IC Commercial developments. ACHD previously acted on both applications and based on the findings of the traffic impact study for the Meridian IC Commercial (which included the traffic from Tanner Creek) the Meridian Road/Waltman Lane intersection would exceed ACHD's Acceptable Level of Service Thresholds. ACHD staff report did not recommend any mitigation at the intersection due to right-of-way constraints, impacts to existing businesses, and substantial intersection redesign and construction, making the recommended mitigation infeasible. The memo prepared by Six Mile was in response to comments and feedbackthat were made during Meridian City Council meetings. A three-phase concept design is presented in the memo; the first two designs did not require any additional right-of-way dedication and the final phase did. ACHD's review focused on the two designs that did not require additional right-of-way dedication. ACHD was not consulted during the preparation of the memo. After reviewing the information provided, ACHD does not recommend making any modifications to the Meridian Road/Waltman Lane intersection. Under all concept designs, modifications to the existing northbound travel lanes and storage on the 1-84 SPUI would be impacted or reduced to benefit the site, negatively impacting the SPUI's operations of both the interchange and the ramps. The intersections in this area operate in an atypical coordinated signal system and the priority operation in this area is the movement of vehicles on Meridian Road on and off 1-84 and through the City of Meridian, not the accommodation of the turning movements of development-related traffic. ACHD's concerns also extend to the impacts of proposed modifications to the Central Road and Corporate Drive intersections at Main Street and Progressive Drive. While the proposed improvements may benefit the Tanner Creek and Meridian IC developments in the short term, they will likely negatively impact the already congested area roadways and con netting you to more Ada County Highway District•3775Adams Street•Garden City,ID•83714-PH 208 387-6100-FX 345-7650•www.achdidaho.org intersections. The proposed changes without significant widening increase corridor travel times and interchange queue lengths,further compounding existing congestion in this area. The priority for agency stakeholders in this area is the operations of the Meridian Road/1-84 SPUI interchange; reduction of turn lane queues and on-ramp access should not be considered to accommodate development applications. ACHD believes there are other alternatives not taken into consideration such as converting Central Drive/Waltman Lane and Corporate Drive to a one-way couplet. This is anticipated to reduce both queue lengths and the impacts to Meridian Road and the 1-84 interchange system. The City of Meridian has previously approved several commercial projects in this area which generate a significant amount of vehicular traffic.As such, additional congestion is expected during the peak hours; especially combined with the interstate access at Meridian Road. If the City of Meridian wants to allow the proposed developments to move forward, then higher levels of congestion need to be accepted. If higher levels of congestion are not acceptable to the city, then a reduction in scope/scale of the development or revisions to the phasing to coincide with ACHD's planned capital improvement projects should be considered, as noted in ACHD's Mitigation Policy (§7106.7). Although ACHD does not have any planned improvements in the vicinity of the site, there are area improvements planned which should improve traffic conditions on Meridian Road and the Meridian Road/1-84 SPUI interchange. ACHD's Integrated Five Year Work Plan currently has the Linder Road overpass scheduled for construction in 2026-2027 and ITD's SH-16 extension project is in various stages of construction. Both projects provide additional north/south connectivity and travel options for the western portion of Ada County. After discussion of the projects (Tanner Creek and Meridian IC Commercial) with City of Meridian staff, ACHD was tasked to analyze the impacts if only the single-family portion of the Tanner Creek and onlythe Free-Standing Discount Superstore (Target) were constructed prior to the completion of ACHD's Linder Road overpass project. Based on the information included in the traffic impact studies prepare for both developments and under this limited scenario, the roadway segment of Waltman Lane is anticipated to operate at an acceptable level of service threshold and the intersection of Meridian Road/Waltman Lane is anticipated to slightly exceed ACHD acceptable level of service thresholds. It is likely that the intersection would operate better than reported in the traffic impact studies once the stub streets to the adjacent neighborhoods are connected and Cooperate Drive is extended to intersect Waltman Lane, making this a viable alternative. In summary, ACHD will not be making any revisions to the staff reports for Tanner Creek or Meridian IC Commercial (CPA and AZ). The City of Meridian should consider the phasing/timing of both projects as they relate to ACHD's Linder Road overpass project. The City and ACHD may need to look at alternatives for alleviating traffic congestion in this area, such as the conversion of two-way streets to one-way couplets. connecting you to more Ada County Highway District•3775Adams Street•Carden City,ID•83714-PH 208 387-6100-FX 345-7650•www.achdidaho.org Please let me know if you have any questions. Mindy Mindy Wallace,AICP Planning Review Supervisor Development Services CC: Sonya Allen -City of Meridian Bill Parsons-City of Meridian Brian McClure-City of Meridian connecting you to more Ada County Highway District•3775Adams Street•Carden City,ID•83714-PH 208 387-6100-FX 345-7650•www.achdidaho.org