Answer: We could slow the speed limit down, or add more stop signs/lights. We could also try adding a safer sidewalk.
Explanation: If we slowed down the speed limit, the cars wouldn't go so fast. Bikes are affected by speed and air, and could tilt if the speed is too high. Most places have very bumpy sidewalks, and could flatten the tires or slow the bicyclist down. Stoplights show the cars that other people need to go, and adding more could help the bicyclist know if it is safe to move.