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HomeMy WebLinkAboutMONTAVA - PHASE G & IRRIGATION POND - BDR210013 - SUBMITTAL DOCUMENTS - ROUND 3 - VARIANCE REQUEST kimley-horn.com 13455 Noel Road, Two Galleria Office Tower, Ste 700, Dallas, TX 75254 (972) 770-1300 July 11, 2022 Max Moss, President HF2M Colorado 430 N College Ave. Suite 410 Fort Collins, CO 80524 Re: Montava Master Planning – Timberline Road Variances Memorandum INTRODUCTION In preparing the engineering design for Timberline Road for the Montava development, the Larimer County Urban Area Street Standards (LCUASS) have been referenced for the applicable design parameters associated with the proposed Major Collector Road that is Timberline Road from Mountain Vista Dr to Country Club Road. Timberline Road reflects the vision of Montava as a walkable and bikeable corridor with accessible public space routes and a separated ped-bike path with the goal of implementing the principles to be a Vision Zero corridor. Key components of Timberline Road that are purposefully proposed consist of:  Low-speed intersections that separate and reduce the number and potential severity of conflict points.  Pavement markings and signage that are reflective of road user behavior and understanding to reduce clutter and prolonged decision-making  Aesthetic features that reinforce the pedestrian and bicyclist as the safety priority while maintaining reciprocal sight distance for all users and their variable operating speeds IDENTIFIED VARIANCES Table 1 contains the associated variance requests for the proposed engineering design of Timberline Road with respect to the Larimer County Urban Area Street Standards. Each variance has been labeled with the section where it is found in the LCUASS, the LCUASS value, the value being proposed for Timberline Road, and the reason for the variance request. Table 1 - Montava Timberline Road LCUASS Variance List Variance Request No. LCUASS Section Design Criteria Reason for the Variance Request 1 Table 7-3 Provide 150ft minimum tangent between successive curves or at intersections Adjacent to the Chesapeake and Longwood intersections, Timberline Road is proposed to use reverse curvature to slow vehicle speeds prior to the intersections (Zero tangent between successive horizontal curves). Approximately 30- feet of tangent is provided from the perimeter of the intersection to the first horizontal curve. 2 Table 7-3 Major Collector requires minimum 600ft horizontal radius Adjacent to the Chesapeake and Longwood intersections, Timberline Road is proposed to use 50ft minimum radii to slow vehicle speeds kimley-horn.com 13455 Noel Road, Two Galleria Office Tower, Ste 700, Dallas, TX 75254 (972) 770-1300 Variance Request No. LCUASS Section Design Criteria Reason for the Variance Request prior to the intersections. The additional width required for larger trucks (larger wheelbase vehicles) would be accommodated via a truck overtracking pad (“truck blister”). The centerline alignment of the Timberline corridor maintains the 600ft minimum horizontal radius value, it is only the lane geometries/curbs that would make use of the smaller radii to purposefully reduce vehicle speeds. 3 7.7.6.B Drive-over combination curb and gutter on Local Roadways only. Use drive-over combination curb and gutter (truck blisters) at the Chesapeake and Longwood intersections and at the Country Club Road roundabout to provide accommodation for vehicles larger than the largest anticipated Fire Department apparatus. 4 8.2.8 WB-50 design vehicle accommodation (at Major Collector and Local Residential the vehicle may have to back up to complete the turn) No variance appears to be required if Chesapeake and Longwood are classified as Residential Local streets. 5 Appendix I, B.3 All single-lane roundabouts shall be designed to allow single passenger cars, pickups, single unit (SU) trucks and fire trucks (B-40, BUS-45 AND WB-45) to proceed without requiring the use of the truck apron. Vehicles larger than the largest Fire Department apparatus will be accommodated by truck blisters, a 3-inch rise sloped and mountable curb that includes rigid pavement beyond the curb where the wheel paths of larger vehicles can be accommodated without encroaching into vegetated or pedestrian/bicycle-designated areas. This variance would be applicable at the Country Club roundabout. 6 Appendix I, B.3 In the determination of vehicular travel/turning paths, the gutter pans may not be considered as part of the traveled way, and vehicles shall not be proposed to utilize these areas while negotiating the roundabout. As such, the designer shall assume a two-foot (2’) offset from the face of To reduce vehicle speeds to provide enhanced safety for pedestrians and bicyclists the proposed lanes at the roundabout are intentionally being designed to be too narrow for vehicles larger than a SU-30. Truck blisters will accommodate larger vehicles. These larger vehicles would make use of the gutter pans within the traveled way. This variance would be applicable at the Country Club roundabout. kimley-horn.com 13455 Noel Road, Two Galleria Office Tower, Ste 700, Dallas, TX 75254 (972) 770-1300 Variance Request No. LCUASS Section Design Criteria Reason for the Variance Request curb when defining acceptable truck paths 7 Appendix I, B.3 All roundabouts shall be designed to accommodate the passage of a WB-67 vehicle Use of a WB-67(MOD) design vehicle per the memo drafted on July 1, 2022. The WB-67(MOD) design vehicle has a 53-foot trailer with a 41-foot wheelbase and is considered to be more conservative than the largest truck that is anticipated to access Montava. A WB-67 would be an over-conservative design vehicle that would result in excess widths of travel lanes and larger radii that can lead to faster vehicle speeds through an intersection. This variance would be applicable at all roundabouts proposed within Montava. Currently the variance would apply to the proposed 2x2 roundabout at Mountain Vista and Timberline and the single-lane roundabout at Country Club and Timberline. RECOMMENDATION The engineering design parameters proposed for which variance requests are being made within this memorandum are not unique to Montava. Key principles to safer multi-modal corridors start with narrowed lanes and strategically include such design elements as chicanes, reduced radii values for slower speeds while accommodating larger vehicles with overtracking pads (truck blisters), and context-focused selection of design vehicles. Many Vision Zero agencies are moving towards these similar parameters to reduce high severity crashes in their communities. It is our recommendation that these variance requests be submitted to the City of Fort Collins for review and consideration for a safer Timberline Road.