Rebecca W. Arnold, President Sara M. Baker, Vice President John S. Franden, Commissioner Carol A. McKee, Commissioner Mitchell Jaurena, Commissioner June 19, 2012 Planning & Programming Department TO: FROM: ACHD Commissioners, Director Wong Matt Edmond, Senior Transportation Planner SUBJECT: Ten Mile Corridor Intersection Analysis & Recommendations for Adoption Regular Agenda June 27, 2012 Commission Meeting Executive Summary The purpose of this memorandum is to identify how to address interim and long term (2035+) transportation improvement needs at the six major unimproved intersections on Ten Mile Road between I-84 and Kuna. If adopted, these recommendations will be added to the Master Street Map in order to improve the District s ability to preserve the appropriate right-of-way at intersections and provide a scope for future projects not identified in the Capital Improvements Plan (CIP). Based on the Ten Mile Analysis conducted, and in consideration of the findings and recommendations of the South Meridian Study Analysis and 2012 CIP update, staff makes the following recommendations for interim improvements and long term improvement/right-of-way preservation at each intersection. Additional details are included in Attachment 1. These recommendations include two changes from the previous configurations presented to the Commission: the Victory intersection reflects the configuration from the adopted CIP update, and the Hubbard intersection was changed from a single-lane to a multi-lane roundabout with two lanes on the Ten Mile approaches. Table 1: Recommended Interim Improvement and Long Term Improvement/ROW Preservation Proposed Improvements Intersection Recommended Interim Improvement Recommended Long-Term Improvement / Right-of-Way Preservation Traffic Control Device Estimated Timeframe Traffic Control Device Estimated Timeframe Ten Mile & Victory Interim Signal In Progress Ultimate 5 x 6 Signal 2016-2025 Ten Mile & Amity Interim Signal 2014-2018 (in FYWP) Ultimate 7 x 7 Signal 2023-2026 Ten Mile & Lake Hazel Single-Lane Roundabout 2015-2020 (add to FYWP prioritization) Dual-Lane Roundabout with SB bypass lane 2024 Ten Mile & Columbia Single-Lane Roundabout 2015-2020 (add to FYWP priortization) Dual-Lane Roundabout 2026 Ten Mile & Hubbard All-Way Stop TBD Multi-Lane Roundabout 2028-2033 Ten Mile & Deer Flat All-Way Stop TBD Single-Lane Roundabout 2035+ Ada County Highway District 3775 Adams Street Garden City, ID 83714 PH 208 387-6100 FX 345-7650 www.achdidaho.org
Background The opening of the Ten Mile Interchange prompted ACHD staff to analyze the transportation needs at the six major unimproved intersections along Ten Mile Road south of I-84. This analysis included the timing of interim improvements as well as the timing and configuration of ultimate improvements that would ensure efficient traffic operations through the year 2035. The following outlines a brief history of the Ten Mile Analysis: May 2011: Ten Mile Interchange opened. July 2011: ACHD staff completed initial Ten Mile Analysis of intersections. September 2011: Roundabout templates updated. December 2011: Work session with ACHD commission and staff brief to Kuna and Meridian city councils on findings of Ten Mile Analysis. January 2012: South Meridian Study traffic analysis began. Project limits included the area bounded by Linder, Lake Hazel, McDermott, and Overland. March 2012: Public involvement meeting and comment period May 2012: ACHD Commission adopted CIP update. June 2012: ACHD staff reconciled Ten Mile Analysis with CIP update and South Meridian Study. Facts and Findings During the public involvement meeting and ensuing public comment period, ACHD received 34 written comments. Approximately two-thirds of the comments were generally supportive of the improvements proposed, and a majority expressed support for roundabouts. About one-quarter of the comments were critical of the proposed improvements, and four expressed opposition to or concern over the proposed roundabouts. The most frequent comment against the proposed improvements was against installing an all-way stop at Hubbard or Deer Flat. Fiscal Implications Right-of-way is designated as impact fee eligible in the recently adopted CIP. Additional right-of-way must be dedicated as a condition of development. Programming of projects for construction will be done through the Five-Year Work Plan. Policy Implications This action will establish the first preservation footprints for intersections in the Master Street Map. Alternatives for the Ten Mile Corridor Intersection Analysis The Commission has the following alternatives: 1) Adopt the recommendations of the Ten Mile Analysis and add to the Master Street Map. 2) Adopt the recommendations of the Ten Mile Analysis with Commission-directed changes. 3) Remand the Ten Mile Analysis to staff with additional direction. Staff Recommendation Staff recommends Alternative 1: Adopt the recommendations of the Ten Mile Analysis and add to the Master Street Map. Attachment(s): 1. Discussion and Diagrams of Long-Term Intersection Recommendations 2. Letter from Mayor de Weerd 2
Attachment 1: Discussion and Diagrams of Long-Term Intersection Recommendations Ten Mile & Victory Intersection An interim signal is in the process of being installed at this intersection. for Ten Mile Road and 3 lanes for Victory Road. The Ten Mile Analysis forecasted this intersection would operate acceptably as a conventional intersection with dual thru/receiving lanes and a dedicated left turn lane on each approach, with the addition of a dedicated right turn lane on the southbound and westbound approaches. This indicated the possible need to expand Victory Road from 3 lanes as currently called for in the Master Street Map to 5 lanes. Since that time, however, the South Meridian Study determined that Victory Road would remain constrained to 3 lanes. Additionally, the CIP update and South Meridian Study determined that the intersection should have dual thru/receiving lanes and a left turn lane on the Ten Mile approaches, a single thru-receiving lane and dual left turn lanes on the Victory approaches, and dedicated right turn lanes on all approaches. Additionally, the City of Meridian has requested that ACHD preserve right-of-way for dedicated right turn lanes on all approaches at this intersection. Staff recommends preserving right-of-way in accordance with the improvements listed in both the CIP update and the South Meridian Study. Ten Mile & Amity Intersection An interim signal is programmed in the FYWP in Preliminary Development (PD). The Master Street Map currently prescribes preservation for 5 lanes for both Ten Mile Road and Amity Road. The Ten Mile Analysis forecasts this intersection would operate acceptably as a conventional 7x7 intersection with dual thru/receiving lanes, dual left turn lanes, and a dedicated right turn lane on each approach in 2035. This is consistent with the recently adopted CIP update and Meridian s request to preserve right-of-way of dedicated right turn lanes on all approaches. Although the South Meridian Study forecasts that only single left turn lanes would be needed on the north and south legs in 2035, these movements would be operating near capacity. Therefore, staff recommends preserving right-of-way in accordance with the Ten Mile Analysis and CIP update, with dual left turn lanes on the north and south legs. Ten Mile & Lake Hazel Intersection for both Ten Mile Road and Lake Hazel Road. The Ten Mile Analysis forecasts this intersection would operate acceptably as a dual lane roundabout with a southbound right-turn bypass lane in 2035. This is consistent with the recently adopted CIP update. The South Meridian Study is forecasting that this intersection would require a conventional 7x7 intersection to operate acceptably in 2035. This is due to the fact that the Ten Mile Analysis assumed Lake Hazel at 3 lanes and the South Meridian Study assumed Lake Hazel at 5 lanes. Staff recommends preserving right-of-way in accordance with the Ten Mile
Attachment 1: Discussion and Diagrams of Long-Term Intersection Recommendations Analysis and CIP update in order to maintain consistency with the proposed roundabout corridor to the south. Ten Mile & Columbia Intersection for Ten Mile Road and 3 lanes for Columbia Road. The Ten Mile Analysis forecasts that this intersection would operate acceptably as a dual lane roundabout in 2035. This is consistent with the recently adopted CIP update, and this intersection was not included in the South Meridian Study. Staff recommends preserving right-of-way in accordance with the Ten Mile Analysis and CIP update. Ten Mile & Hubbard Intersection for Ten Mile Road and 3 lanes for Hubbard Road. The Ten Mile Analysis forecasts that this intersection would operate acceptably as a single lane roundabout in 2035. This intersection was not included in either the CIP update or the South Meridian Study. Although the Ten Mile Analysis forecasts that a single lane roundabout would be adequate in 2035, staff recommends preserving right-of-way for a multilane roundabout, with dual lanes on the Ten Mile approaches, in order to accommodate the potential widening of Ten Mile to five lanes through the intersection. Ten Mile & Deer Flat Intersection for both Ten Mile Road and Deer Flat Road. The Ten Mile Analysis forecasts that this intersection would operate acceptably as either an all-way stop or a single lane roundabout in 2035. This intersection was not included in either the CIP or South Meridian Study. Although a single lane roundabout could not accommodate 5 lane road segments, as the Master Street Map is currently preserving for on Ten Mile and Deer Flat, no modeling to date has forecast future traffic volumes that would justify widening either of these roads to 5 lanes near this intersection. Therefore, staff recommends preserving for a single-lane roundabout at this intersection, and conducting follow-on analysis of whether the Master Street Map should continue to preserve for 5 lanes along the adjacent road segments.