Interstate 77 - History

History

Officially designated to run from Port Huron to Charlotte, I-77 appeared on the original Interstate system route numbering plan in 1957. The part of Interstate 94 from Detroit northeast to Port Huron, Michigan was originally planned as I-77 in 1957; the current I-77 was I-79. When the current Interstate 79 was added in Pennsylvania, the I-77 designation was moved to its current route, but the I-77 in Michigan also remained in the 1958 numbering plan. It soon became part of I-94.

Originally, I-77 was to terminate at Interstate 85 in Charlotte. However, Congress, in its 1969 amendments to the Interstate Highway Act, added an extension of I-77 from I-85, through a rapidly-growing corridor from downtown Charlotte (along an upgrading of US 21 already under construction in some places), into South Carolina near Rock Hill. The highway under this plan was to continue to Columbia, South Carolina, terminating at an interchange with Interstate 20. Collector / distributor ramps to both Alpine and Percival Roads were proposed later on to more efficiently route traffic to and from the Fort Jackson military reservation and the I-77 / I-20 corridors. Additionally, SC-277 was put on the books as well to bring southbound traffic from I-77 directly into the heart of downtown Columbia.

By the late 1970s, the southern terminus of I-77 near Columbia, South Carolina was amended to a grade-separated interchange with SC 12 (Percival Road) with mile markers signed accordingly. This extension was completed in 1986. That same year, the first phase of an interstate spur (to be named Interstate 326) between SC 760 (Jackson Boulevard) and Interstate 26 was opened as far as Bluff Road (SC-48). 1989 saw a two-mile (3 km) extension to the east, adding interchanges at Shop Road (later SC-768) and Garner's Ferry Road / Sumter Highway (US 76/US 378).

The decision to extend I-77 from SC 12 and SC 760 (five miles between the two roads) was made before I-326 was opened, so the southern portion was never signed as such, instead re-designated by SC DOT as SC-478. The northern part of extension was completed as far as Forest Drive in early 1993, with the final 3 miles (4.8 km), including the SC-760 interchange, opened to traffic in 1995. The mile markers and exit numbers for Interstate 77 were adjusted accordingly as the extension was completed. As the Percival Road to I-26 section was under construction, southbound traffic on I-77 was detoured, by "Temporary I-77" signage, via I-20 and I-26 to bypass Columbia.