What is the maximum slope percentage recommended for parking lots without requiring grading?

The maximum slope percentage recommended for parking lots without requiring grading is commonly set at 3%. This figure is rooted in considerations for safety, accessibility, and drainage. A slope of 3% provides a gentle incline that facilitates ease of movement for vehicles and pedestrians, minimizing the risk of slipping, particularly in wet conditions. It also ensures that those with mobility impairments can navigate the space without undue difficulty.

Additionally, maintaining a lower slope helps manage rainwater runoff more effectively, reducing potential flooding issues and encouraging proper drainage. Steeper slopes would complicate these issues and could necessitate additional design solutions, such as grading or the installation of drainage systems, in order to meet safety and functional standards.