On single-building commercial sites, the accessible route is straightforward: from the accessible parking space to the building entry, at compliant slopes. On campus sites — schools, medical centers, corporate campuses, shopping centers, multi-building complexes — the accessible route network becomes a design challenge that can reshape the grading plan, the building placement, and the site circulation.

What the Code Requires

The Americans with Disabilities Act (ADA) and ADA Standards for Accessible Design require an accessible route from public transportation stops, accessible parking, and public sidewalks to every accessible building entrance, and between every building and facility on the site. The accessible route must connect all elements that people with disabilities need to use.

Key requirements for the accessible route:

• Minimum clear width: 36 inches (44 inches in some corridors). 60 inches where two wheelchair users must pass each other.
• Running slope: 5 percent maximum (1:20). Running slopes exceeding 5 percent must comply with ramp requirements (maximum 8.33 percent, handrails, landings every 30 feet of rise).
• Cross-slope: 2 percent maximum (1:50). This is the most restrictive and most frequently violated slope requirement on accessible routes.
• Surface: Firm, stable, and slip-resistant. No loose gravel, sand, or uncompacted soil. Concrete, asphalt, pavers, and compacted decomposed granite (in some applications) qualify.
• Changes in level: Up to 1/4 inch may be vertical. Between 1/4 and 1/2 inch must be beveled at 1:2 maximum. Changes greater than 1/2 inch require a ramp or elevator.

The Campus Challenge

On a campus with multiple buildings at different elevations, the accessible route must connect all buildings while maintaining the slope limits. If Building A is at elevation 100 and Building B is at elevation 108, the accessible route between them must cover the 8-foot elevation change at no more than 5 percent running slope — which means the route must be at least 160 feet long. If the site design places the buildings 100 feet apart, the direct path has an 8 percent slope and does not comply. You either need a longer, switchback route, a ramp with landings, or you need to redesign the grading to reduce the elevation difference.

Common Solutions

• Switchback paths: Accessible routes that serpentine across the slope to maintain compliant running slopes. Effective but consume significant site area.
• Ramps with landings: Ramp segments at up to 8.33 percent slope with level landings (60 inches minimum length) every 30 inches of vertical rise. Ramps need handrails on both sides, edge protection, and clear landings at the top and bottom. They are the standard solution for short elevation changes (2 to 5 feet).
• Elevators or lifts: For larger elevation changes or constrained sites where exterior ramps are impractical. Elevators are required in most multi-story buildings, but exterior elevators are expensive and introduce maintenance and security considerations.
• Regrading: Adjusting building pad elevations to reduce the grade difference between buildings. This is the most effective solution when it is possible, because it eliminates the need for ramps and switchbacks.

The 2 Percent Cross-Slope Problem

Maintaining 2 percent maximum cross-slope on an accessible route that traverses a sloped site is the most common design failure. The natural tendency is to let the path follow the existing terrain, which creates cross-slopes wherever the path traverses a slope that is steeper than 2 percent in the direction perpendicular to the path.

For example, a sidewalk running north-south along a hillside that slopes 5 percent east-west will have a 5 percent cross-slope unless the sidewalk is built on a bench cut into the hillside. The bench creates a retaining wall (or a graded slope) on the uphill side and an elevated edge on the downhill side. This is expensive, but it is the only way to maintain the 2 percent cross-slope requirement on sloped terrain.

Design Process for Campus Accessible Routes

1. Map all destinations. Every building entry, parking lot, transit stop, outdoor gathering area, and recreational facility that is open to the public must be connected by an accessible route.
2. Identify the shortest paths. For each pair of connected destinations, determine the shortest feasible route. If the direct path exceeds 5 percent running slope or 2 percent cross-slope, identify alternative routes.
3. Run the slope calculations. For each proposed accessible route segment, calculate the running slope and cross-slope from the grading plan. Civil 3D and similar software can generate slope analysis maps that show where the surface exceeds the ADA limits.
4. Design solutions for non-compliant segments. Ramps, switchbacks, regrading, or alternative routes. Document the accessible route on the plans with slope arrows and callouts showing the running slope and cross-slope at critical points.
5. Verify at the driveway crossings. Every point where the accessible route crosses a driveway or vehicular path must maintain 2 percent maximum cross-slope. This is where most violations occur.

Signage and Wayfinding

On large campuses, the accessible route may not be the most direct route between destinations. When the accessible route diverges from the general pedestrian path, directional signage is required to guide people with disabilities to the accessible route. Signs must include the International Symbol of Accessibility and directional arrows.

Common Plan Check Comments

• "Provide an accessible route between Building A and Building B. Show running slope and cross-slope at all segments." — The reviewer wants to see the route on the plan with slope values annotated.
• "Cross-slope exceeds 2% at the accessible route crossing of the driveway at grid line X." — Redesign the driveway grade or provide a separated crossing with compliant slopes.
• "Running slope exceeds 5%. If the slope exceeds 5%, the path is a ramp. Provide handrails and landings per ADA Standards Section 405." — Either reduce the slope or design the segment as a ramp with all ramp requirements.