Interstate, toll roads and major US highways. Line segments were reselected via attribute code for interstate, and toll roads. Major US highways were selected visually to complete road networks between interstates and toll roads. Additional US highways were selected where other major roads were sparse. Information describing each line segment is contained in the line attribute table mjroad.
Information describing each line segment is contained in the line attribute table stateroadsdd.
Line segments were reselected via attribute code representing US highways. Additional US highways were selected where visually selected to correct miscoded line segments. Information describing each line segment is contained in the line attribute table usroad.