[header] How to operate a wheelchair safely outdoors [title] Stay on even surfaces. [step] Uneven surfaces can make any wheelchair get off balance. Even when someone is pushing a wheelchair, an uneven surface can cause harm. 
Users and caregivers alike need to stick to slopes that only go up to a gradient of 20% and are dry, solid, and straight. [substeps] Avoid inclines, slopes, staircases, and curbs.