You can create a rough texture on a concrete ramp by brushing the surface with a broom before it hardens. Ramps should have level landings at the top and bottom. The top landing keeps the user from rolling or falling backward when trying to open or close the door. The bottom landing allows the user to make an easy transition to level ground. Landings should be at least as wide as the ramp leading to it, and should have a minimum length of 60 inches.
Guardrails keep people and wheels safely on the ramp at all times.
Edging a few inches high should be mounted along the edge of the ramp. Handrails on both sides of the ramp. Use wood, since metal may be uncomfortable to use in wintertime. A shelter from the weather. If you've built your ramp close to the house, consider putting a small extension on the house roof to cover the ramp and protect users from bad weather.