Legislation requires that a ramp be provided at pedestrian walkways, which are intersected by curbs. SHA standard ramps are generally compliant with the currently accepted guidelines. However, the standards do not address all potential conditions and constraints. Additional ramp designs are provided within the referenced guidelines. In cases where none of these standards or designs is appropriate, the designer is required to provide detailed designs for the special ramps. The following principles shall be followed for the application of standards and special designs (See Figure 1):

• Ramps shall be perpendicular to the curb (even on a radius).
• Each side of the ramp shall have an equal run.
• Ramp running slopes shall be 12:1 maximum. A 10:1 maximum slope is acceptable in areas of existing sidewalks/roadways.
• All slopes shall be measured independent to the surrounding terrain. Therefore, the length of the ramp is solely dependent on the height of the curb (for example, a 6 in. curb with a 12:1 ramp slope should have a 6 ft length).
• The transition between the ramp and gutter shall be smooth. The gutter shall have no lip at the curb.
• Compound slopes in the path of travel shall be avoided.
• Cross-slope on ramps shall be 2% maximum.
• Side flares shall be sloped at 12:1
• Minimum width on sidewalk ramps shall be 40”. The width of multi-use trail ramps shall equal the width of the trail.
• A level landing shall be provided at the top of perpendicular and diagonal ramps or where a change in travel direction is required. This landing should be 60” x 60” – less only where severe physical constraints are present.
• The ramp, not including side slopes, shall be located at least 2’ within the limits of crosswalk striping.
• A construction tolerance for new sidewalk ramps is ± 1%.
• Ramps shall be located to minimize pedestrian exposure to traffic.
• Drainage shall be considered in locating ramps – avoid close proximity to sumps.
• Pedestrian railings should be considered for use on a case by case basis. For safety reasons, railings may be considered when providing a sidewalk adjacent to steep slopes.

FIGURE 1

A CURB RAMP

The image above shows:

Curb Ramp: Isometeric view of a curb ramp as currently defined. The illustration is based on the old "perpendicular" stype ramp.