The most important factor for Public Works is how a fence hinders visibility. Tall, solid fences can block visibility for a car exiting a property. This is especially important in areas that have sidewalks. With a tall solid fence, a car backing out of a driveway, and a child on a bicycle on the sidewalk will not be able to see each other until it is too late. With the varied terrain and irregularly shaped lots in Mill Valley, the amount of sight distance necessary to be preserved is decided on a case-by-case basis. However, if you are submitting a fence application near a driveway or a road, it is suggested you start with a design that limits the fence height to 30 inches within a 10-foot triangular area on either side of the driveway or road.