When parking facing downhill, what is the rule you must follow?

When parking facing downhill, the correct approach is to turn your wheels towards the curb. This practice is important because it helps to prevent the vehicle from rolling into the street if the parking brake fails. By directing the wheels towards the curb, if the vehicle does begin to roll, it will come to a stop against the curb rather than moving into the roadway, which greatly enhances safety for both the vehicle and surrounding traffic.

Other options do not align with this safety measure. Keeping your wheels straight does not offer any protection from the vehicle rolling away. Applying only the handbrake provides some level of security but can be insufficient if the brakes fail, while the guideline to park no closer than 10 feet from the curb does not directly address the critical safety measure of positioning the wheels when parked downhill.