Alluding to the celebratory gesture , the " High Five " name refers to the five flyover ramps handling the left @-@ turn movements that tower over the landscape . The interchange is as high as a 12 @-@ story building , and includes 43 bridges spread across five levels ( the " High Five " ) , 710 support tiers , and 60 miles of additional highway . The highest ramps are 120 feet ( 37 m ) above ground . The lanes of US 75 , which are on the bottom level , are 20 feet ( 6 m ) below ground level , giving the structure a total height of 140 feet from bottom to top As part of the project , I @-@ 635 was widened to include four dedicated high @-@ occupancy vehicle lanes ( HOV lanes ) that are barrier @-@ separated and reversible .