Table 5.3 Horizontal Clearances to Trees and Shrubs: Urban Shoulders

Posted / Design Speeds

Minimum Horizontal Clearance(1)

Tree Size(2)  < 4 inches

< 35 mph

4-ft.

40 to 45 mph

8-ft.

Tree Size(2)  > 4 inches

< 35 mph

8-ft.

< 35 mph
(Commercial Area(3))

4-ft.

8-ft. in median

40 mph

10-ft.

16-ft. in median

45 mph

14-ft.

22-ft. in median

(1)From center of tree to face of curb

(2)Tree size is diameter of the tree at maturity, measured at 6-inches above the base of the tree.

(3)In a Central Business District and/or where commercial businesses are typically directly adjacent to the right-of-way.