Design Overview Section 4 Standard Plans for Design Fall, 2017 Ann Johnson, PE Services Brady Rutman, SRF Consulting Group Overview Design Basics Recommendations: The Zone System Driveway Crossings Pedestrian Curb Ramp Standard Plans Types of Curb Ramps Design Details Alternate Accessible Pedestrian Signals APS Compliance Checklist 2 Public Rights of Way Accessibility Guidelines (PROWAG) Adopted by MnDOTin 2010 Minimum 4 foot wide Pedestrian Access Route (PAR) with a maximum cross slope of 2% is required. The PAR must be continuous and unobstructed. The PAR shall connect accessible elements, spaces and facilities. Cross Slope Steep cross slopes are inconvenient and hazardous Require extra effort by wheelchair users to move forward Become slippery when wet, icy or snowy 3 FHWA: Designing Sidewalks and Trails for Access (2001) 4 1
Longitudinal Slope Sidewalks adjacent to an existing roadway may follow, not exceed the grade of the road. When outside the typical roadway section, recommended maximum grade of 5% Longitudinal Slope On trails or sidewalks on independent alignments, slopes exceeding 5% must be treated as ramps. 8.3% max for a maximum rise of 30 in. with 5-by 5-ft level landings between segments At 8.3% grade, 30 in. rise = 30 ftlong Ramps with a rise greater than 6 in. require handrails. (Does not apply to curb ramps) 5 6 Longitudinal Slope Reduce the impacts of steep or long grades: Decrease cross slope, even to 0% Provide signs that indicate: Grade and length Less steep alternate routes Consider providing handrails Consider providing a refuge or place to rest offline Cross Slope Solution: Pick up elevation change outside the pedestrian access route Consider bus stops when using this design to be sure standards are still met 7 8 2
The Zone System (Recommended, Not Required) Establishing a buffer area between sidewalk and traffic creates a safer and more pleasant place to walk and makes it easier to meet all ADA requirements. The Zone System Roadway Furniture Zone Pedestrian Zone (contains the PAR) 9 10 The Zone System Parking Roadway The Zone System Maintain a 5 wide path when doors of a building are open 3 clearance recommended between building and PAR when doors open toward the PAR Pedestrian Zone (contains the PAR) Furniture Zone 11 12 3
Protruding Objects When obstacles mounted on posts can be approached from the side, they shall not protrude more than 4 inches. Pole-mounted objects that can only be approached from the front shall not protrude more than 12 inches into the sidewalk corridor. Surface Requirements Sidewalks must: Be firm, stable and slip-resistant Be smooth no rough textures, large openings or gaps Avoid using surface treatments that limit usability FHWA: Designing Sidewalks and Trails for Access (2001) 13 14 Surface Continuity Bricks, cobblestones and other textured pavement create: Increased rolling resistance Tripping hazards Painful vibrations to people with brittle bones or spinal cord injuries in wheelchairs Potential maintenance issues Strongly discouraged by PROWAG Surface Continuity Tolerances: Up to ¼ inch: No Treatment ¼ to ½ inch: Bevel Surface (Max grade of 50%) Minimizes the amount of exertion from a wheelchair user Minimizes tripping hazards for all others More than ½ inch: Replace sidewalk panel 15 16 4
Gaps and Grates Grates to have spaces no more than 1/2 inch wide in direction of travel (ADA Standard) Elongated openings shall be placed so that the long dimension is perpendicular to the main direction of travel. Bus Stops PROWAG requires bus boarding and alighting areas to provide a clear length of 8 ft. minimum, measured perpendicular to street, and a clear width of at least 5 ft. Slopes no steeper than 2%. 17 Mn/DOT Road Design Manual, Chapter 11 18 Driveway Crossings Maintenance Maintenance of facilities, both seasonal and repair-related, is required to remaining ADA-compliant. 19 20 5
Driveway Crossings Driveway Crossings Perpendicular Driveway To be used when the driveway PAR is level with or above the top of curb and sidewalk is separated from the road Perpendicular Driveway Sidewalk continues, full width and level, through the driveway Maintain level passage (continuous PAR profile) 21 22 Driveway Crossings Driveway Crossings Perpendicular Offset Driveway To be used when sidewalk is attached to curb Design Option in a Retrofit: Secure additional ROW from adjacent property in order to improve pedestrian access on narrow sidewalks Perpendicular Offset Driveway Sidewalk bends around sloped portion of the driveway 23 24 6
Driveway Crossings Parallel Driveway To be used with ROW constraints prevent use of a level landing and when sidewalk is attached to curb Acceptable Design: Less desirable because it forces users to negotiate two ramps instead of one level surface, also subject to snow and ice collection in the PAR Driveway Crossings Parallel Driveway Sidewalk drops down to elevation of street from both sides 25 26 Driveway Crossings Driveway Crossings Driveways built like driveways encourage slowerspeed turns. Driveways built like intersections encourage higher-speeds. PAR still needs to meet slope and surface requirements 27 28 7
If longitudinal slope exceeds 5 percent, or there is a change in direction, landings must be provided on any pedestrian facility. Maximum ramp slope is 8.3 percent. Maximum length of initial ramp is 15 feet. Slopes and dimensions are absolute. ADA Standards and PROWAG allow no tolerance for exceeding these maximums. Standard Plans Legend 2017: - Ramp Slope Ranges - Landing Areas -Curb Heights X 29 30 Standard Plans - Sheet 1 NOTES: Landings shall be located anywhere the pedestrian access route changes direction, at the top of ramps that have running slopes greater than 5%, and if the approaching walk is inverse grade greater than 2%. Landing 31 32 8
NOTES: Landings shall be located anywhere the pedestrian access route changes direction, at the top of ramps that have running slopes greater than 5%, and if the approaching walk is inverse grade greater than 2%. NOTES: Landings shall be located anywhere the pedestrian access route changes direction, at the top of ramps that have running slopes greater than 5%, and if the approaching walk is inverse grade greater than 2%. Landing 5%-8% Landing 33 34 Curb Ramp Types Perpendicular ramp Tiered perpendicular ramp Parallel ramp Fan ramp Depressed corner Diagonal ramp (not recommended) One-way directional ramp Combined directional ramp 35 Perpendicular Ramp is perpendicular to the curb line Landing S 36 9
Tiered Perpendicular Used where the initial curb ramp cannot make up the elevation difference, so a secondary ramp is needed Parallel Ramp is parallel to the curb line Landing occurs at the bottom of the ramp F Landing S F S Landing S 37 38 Fan Ramp is radial at back of curb, 5% max slope Landing at top of ramp Modified Fan Similar to Fan; Use when ROW is constrained Note 2: 4 min. depth landing required across top of ramp 4 min. 2 Note 8; 7 Min top radius grade break required to be constructible. 39 40 10
Depressed Corner Ramps on approaching walk lead to Landing at bottom Fan Ramps preferred over Depressed Corners due to likelihood of ponding at depressed corner Diagonal Ramp Shall only be used after all other curb ramp types have been evaluated and deemed impractical S S Landing Landing 41 42 Pedestrian Curb Ramp Standard Plans - Sheet 2 Diagonal Ramp 4 x4 clear space required within crosswalk 43 44 11
Pedestrian Curb Ramp Standard One-Way Directional Detectable Warnings to be placed perpendicular to travel at the closest location to the curb with full sidewalk/trail width Note 7: Max 2% slope in all directions and drain to flow line. SHALL be constructed integral with curb and gutter. Directional with Detectable Warnings at Back of Curb When placement of warnings in Standard One-Way Directional exceeds 5 offset from back of curb Note 13: Concrete walk shall be formed and constructed perpendicular to the back of curb. Maintain 3 between edge of domes and edge of concrete. 45 46 Directional with Detectable Warnings at Back of Curb When placement of warnings in Standard One-Way Directional exceeds 5 offset from back of curb Note 13: Concrete walk shall be formed and constructed perpendicular to the back of curb. Maintain 3 between edge of domes and edge of concrete. Directional Ramp Walkable Flare 2% Max. 8%-10% SLOPE 47 48 12
Combined Directional Landing shared by two separate directional ramps at a twoway crossing S Landing S Combined Directional Preferred over Fan/Depressed Corner due to increased clarity of crossing direction Note 3: Min 3 Curb Height (4 Preferred) between domes Note 4: The bump between ramps should not be in direction of pedestrian travel 49 50 Initial curb ramps landings shall be constructed within 15 from the back of curb, with 6 from the back of curb being the preferred distance. Secondary curb ramp landings are required for every 30 of vertical rise when longitudinal slope is greater than 5% Contraction joints shall be constructed along all grade breaks. ¼ deep visual joints shall be used at the tops of concrete flares adjacent to walkable surfaces. Initial Landing Within 15 BOC Secondary Landing Every 30 of Vertical Rise 51 52 13
Pedestrian Curb Ramp Standard Plans - Sheet 3 To ensure initial ramps and initial landings are properly constructed, landings SHALL be cast separately. Follow sidewalk reinforcement details on sheet 6 and the Special Provisions. Prosecution of Work (ADA). 53 54 Curb and Gutter Details Any vertical lip at the flow line shall not be greater than ¼ Perpendicular and parallel ramps can have a maximum 5% gutter slope because the pedestrian s path of travel is perpendicular to the gutter flow line. Curb and Gutter Details: Positive flow line drainage shall be maintained through the PAR at 2% maximum. No ponding shall be present in the PAR Curb ramp types where the pedestrian s travel is not perpendicular to the gutter flow line (i.e. directional, depressed corners and fan ramps) shall have a flattened gutter slope of 2% to 3%. 55 56 14
Curb and Gutter Details Curb machine Placement Optional Sill Curb when sidewalk is at back of curb Curb and Gutter Details Outflow Gutter 5% Max. Note 3 Begin Gutter slope transition 10 outside of all curb ramps. 57 58 Standard Plans - Sheet 4 Side Treatments When adjacent to pavement, flares shall be constructed at 8-10% max slope. When adjacent to turf, 1:6 graded flare is generally preferred. 1:6 8% - 10 % 59 60 15
Side Treatments A walkable surface is defined as a paved surface adjacent to a curb ramp without raised obstacles that could be mistakenly traversed by a user who is visually impaired. A walkable Flare is a concrete flare constructed adjacent to a curb ramp with a slope of 8% - 10% Detectable Edge at Quadrant All constructed curbs must have continuous detectable edge for users with visual impairments. Curb transitions are considered detectable edges when the taper starts within 3 of the edge of truncated domes. Non- Walkable Surface 1:6 Walkable Flares 8%-10% Walkable Surface 61 0 0 3 MINIMUM CURB HEIGHT / 4 PREFERRED CURB TAPER 0 0 62 Pedestrian Approach Nose Detail Note 15: 3 for both upstream and downstream side on medians and splitter islands Detectable Edge Without Curb and Gutter Detectable warnings shall be place 1 from edge of bituminous roadwayn for visual contrast (MnDOT recommendation) Best Practice: Match crosswalk width 1 1 3 2 2 3 63 64 16
Standard Plans - Sheet 5 Rail Crossing Nearest edge of detectable warning surface shall be placed 12 Minimum to 15 Maximum from the nearest rail. For skewed railways in no instance shall the detectable warning be closer than 12 measured perpendicular to the nearest rail. 65 66 Pedestrian Curb Ramp Vertical Face Curb V-curb adjacent to building V-Curb V-curb adjacent to landscape and outside sidewalk limits (preferred) 67 68 17
V-Curb V-curb adjacent to landscape and inside sidewalk limits Semi-Directional Ramp with Walkable Flare 69 70 Push Buttons Push Buttons Push Button Station 71 72 18
Standard Plans - Sheet 6 Standard Plan 73 74 Push Button Location Push Button Location 10 1.5-10 5 Max 75 76 19
Push Button Location Buttons at outside edge of crosswalks Push Button Station New Breakaway Pedestal Push buttons are improperly oriented 77 78 APS Push Button Station and Location Push Button Location 79 80 20
Maintenance Access Route (MAR) Compliance Checklist 1) Push buttons stations are properly placed and the push button faces are oriented properly. 81 82 Compliance Checklist 2) There must be a 4 x 4 landing adjacent to the push button. Compliance Checklist 3) Max 5 distance from crosswalk edge to push button face: 83 84 21
Compliance Checklist 4) 1.5 to 10 Distance from the push buttons to the back of curb (Ideally 4-6 ) Compliance Checklist: 5) Min 10 Distance between the push buttons 10 ft. minimum 85 86 Compliance Checklist: 6) 42 Push button height Compliance Checklist: 7) The push button needs an unobstructed side reach of 10 maximum. Height of 42 +/- 2 42 42 Side Reach 10 Maximum 87 88 22