California Department of Transportation
 

 

Q How wide are freeway lanes?
   
A.

This question is not exactly the easiest to answer because, depending upon when the original portion of a freeway was constructed, the widths can vary. They can also vary a little where lanes have been added to a freeway and there is no more room for expansion.

Overall, the following widths are fairly standard through the state.

An eight lane freeway would consist of an outside shoulder, four travel lanes, an inside shoulder and then on the other side, lanes going in the opposite direction, would be the inside shoulder, 4 travel lanes and an outside shoulder.

Outside Shoulders are generally 10' 4 lanes of travel way are 48' (12' per lane) Inside Shoulders are 8' So overall an eight-lane freeway would be 132' wide on an average.

Inside shoulders can vary from 5' to 8', Outside shoulders can vary from 5' to 10' and travel lanes depending upon the type of highway can vary from 10' to 15'.