A typical driveway slope can range from one percent to 15 percent. A driveway should normally have a minimum slope of one percent to be able to provide for enough drainage of stormwater runoff during rainfall events. A driveway should usually have a maximum slope of 15% for safety reasons.
The actual slopes used for the design of a proposed driveway will depend on the local ordinances. There might even be requirements where there are slope requirements for a certain distance from the start of a driveway before the requirements change for the rest of the driveway.
How Driveway Slopes Are Shown on a Plan
Driveway slopes can be shown on a plan through proposed contours that are usually included on the grading plan. It would take some measuring off of the plans along with some calculations to determine the actual numbers of the slopes. However, these numbers might already be labeled directly on the plans.
Driveway slopes can also be found labeled on the proposed profiles (side views) of the proposed driveway. Reviewing the profiles is a good way to graphically see the slopes of the driveway.
Factors to Consider in Determining a Driveway Slope
The following are some of the factors that should be considered in determining a driveway slope.
1) The slope of the existing ground
2) The proposed grading adjacent to the driveway
3) Proximity of the proposed driveway to property boundaries
Find the Right Balance
The design of a driveway can be complicated with one of the elements including being able to find the right balance of slopes to use. Care should be taken to choose slopes that will provide proper drainage for the driveway while maintaining a safe path for those who use the driveway.