Depressed freeways are usually located at a depth of 16-ft or more below the surface of adjacent streets. Major streets pass over this type of freeway, and the depression reduces noise while also allowing surface streets to cross at grade.

Front slopes are not generally used beyond the shoulder of depressed freeways, and in such cases, back slopes should not exceed a slope of 1V:3H. Retaining walls along the freeway should preferably be located a minimum of 2-ft beyond the outer shoulder edge. Minimum median widths should be 10 to 22-ft, and any increase should be in multiples of 12-ft to allow for the addition of more through lanes in the future. Where ROW is extremely limited or costly, walled sections with overhanging frontage roads may be utilized.