The myth still exists that a tree’s roots are a mirror image of its crown.  This is not only far from the truth, it is also dangerous to tree health.  In reality, the life-giving roots are usually:

• Spreading to a distance of 1- to 2-times the height of the tree
• Growing within about 2 feet of the surface

So, give ‘em room!  Remember where they are at when you dig a trench, pave, or change the soil grade.  Also, when planting street trees, use a search engine to find out how Silva Cells or C-U Structural Soil can give tree roots a place to safely grow.