Comprehensive Transportation Plan - March 2019

MULTI-USE PATH DESIGN GUIDELINES

Longitudinal Grades Longitudinal grade is also referred to as running grade. In 2011, the United States Access Board (USAB) issued the Advance Notice of Proposed Rulemaking (ANPRM) on Accessibility Guidelines for Shared Use Paths and, in 2013, a supplemental notice of rulemaking (SNPRM) to provide clarification on the longitudinal grade requirements. Table F-4 provides regulatory constraints that would include federal, state, or local laws with the purpose of preserving threatened or endangered species; the environment; or archaeological, cultural, historical, or significant natural features that would be adversely affected by the additional gradient. However, USAB acknowledged that there will be circumstances in which full compliance with the grade requirements may not be practical due to physical or regulatory constraints. Physical constraints would include existing terrain or infrastructure, right-of-way availability, notable natural features, or any similar existing physical constraint. The suggested minimum longitudinal grade is 0.5 percent. The information below provides more clarity about special cases for implementation. Guidelines x Multi-use paths will not exceed the general grade established for the adjacent street or highway, within a highway or street right-of way. x Maximum 5% grade within a highway or street right-of-way. Table F-4. Maximum Running Slope and Segment Length when Physical or Regulatory Constraints Exist RUNNING SLOPE OF TRAIL SEGMENT MAXIMUM LENGTH OF SEGMENT Steeper Than But Not Steeper Than 1:20 (5%) 1:12 (8.33%) 200 feet 1:12 (8.33%) 1:10 (10%) 30 feet 1:10 (10%) 1:8 (12%) 10 feet If the terrain requires steep runs longer than the allowable distance, resting intervals need to be provided at the top and bottom of each segment. A resting interval is also required any time the running slope exceeds 1:20 (five percent). Resting intervals may be provided within or adjacent to the path tread. When the resting area is within the path tread, it must be 60 inches long and at least as wide as the path. When the resting area is adjacent to the path, it must be 60 inches long and 36 inches wide and provide a minimum 4-foot by 4-foot turning space. The surface of the resting area cannot exceed 1:48 (two percent) in any direction. Ramps and Landings Curb ramps provide access between the multi-use path and roadway for people using wheelchairs, strollers, walkers, crutches, handcarts, bicycles, and for pedestrians with mobility impairments who have trouble stepping up and down high curbs. Curb ramps must be installed at all intersections and midblock locations where pedestrian crossings exist, as mandated by federal legislation (1973 Rehabilitation Act and 1990 Americans with Disabilities Act). The running slope of a curb ramp must not exceed 1:12 (8.33%). Guidelines x Detectable warnings need to be placed across the path width, adjacent to the roadway. x Proposed Rights of Way Accessibility Guidel ines (PROWAG) states handrails are required on ramp runs with a rise greater than 6 inches, but are not required for pedestrian circulation paths. x Any side flares associated with the ramp must be outside the path width. Figure F-6. Typical Pavement Structural Sections for Multi-Use Paths Surface Material

The specific pavement section for multi-use paths is dependent on the site specific soils, loads, and construction practices. According to AASHTO, cement concrete typically has a longer service life, reduced susceptibility to cracking and deformation from roots and weeds, and a more consistent riding surface after years of use and exposure to natural elements. A drawback of cement concrete pavements is that pavement markings (such as centerlines) can have a lower contrast against the concrete surface. Asphalt includes a smooth surface, but is less durable with a typical life expectancy of 15-20 years. Unpaved surfaces are typically only appropriate on rural paths, where the intended use of the path is primarily recreational, or as a temporary measure to open a path before funding is available for paving. Within the Town of Morrisville asphalt should be used for paths outside of roadway rights-of-way, and concrete should be used for paths within roadway rights-of-way. Figure F-6 on this page shows a range of materials that may be used for multi-use paths.

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