is a western bypass of Macon, shortening the trip for through I-75 traffic. The Georgia Department of Transportation maintains only 16 percent of the roads in the state. The other 84 percent are the responsibility of the counties and cities; 75 percent of those roads are county roads. GDOT maintains approximately 18,000 miles of state routes and has maintained this mileage cap since the early 1970s. This has led to a significant shift of road responsibility from state responsibility to local governments. This is because the state highway system has not been allowed to grow in proportion to the massive overall road system growth due to rapid population increases statewide over the past 40 years. This has left many urbanized counties forced to maintain many miles of arterial routes and a few freeways due to inability to get these roads onto the state highway system. Freeing the Freeways The Freeing the Freeways program is the largest urban expressway reconstruction project of the late 20th century. The program involved widening the all the interstate highways within the beltway of Atlanta. The Federal Highway Act of 1976 allowed states for the first time to use federal highway dollars to widen and build new interchanges on existing highways. This change to federal policy and subsequent similar changes in the 1978 Surface Transportation Assistance Act and 1981 Federal-Aid Highway Act allowed Georgia to rebuild metro Atlanta interstates with 90/10 federal support. The project cost $1.5 billion and doubled Atlanta's freeway lane miles from . The project sought to increase lanes from six to eight on I-20, I-75, I-85, and I-285 and 10 lanes on the downtown connector involved and was phased over 13 years between 1976 and 1988. During this time, auxiliary interstates in the Atlanta metropolitan area would be constructed and open including Interstate 575 (construction began in 1979 and was completed in 1985) and Interstate 675 (construction began in 1982 and was completed in 1987). Widening of I-285 took place first, in order to allow drivers to bypass the construction when it took place within the beltway. Construction began on the northern arc of I-285 from Paces Ferry Road just west of I-75 to Chamblee Tucker Road just east of I-85 in 1976, and it was completed by 1978. The radiating expressways were then upgraded. By July of 1985, I-75 and I-85 had both been widened from the Brookwood Split to north