Historically used in the planning and development of roadway projects, straight-line diagrams are graphic illustrations of the construction history of North Carolina's Interstate, U.S., and N.C. route systems for a particular period.

In 2004, the N.C. Department of Transportation discontinued the creation and updates of diagrams and other geometric information on the diagrams (pavement type, width, shoulders, etc.) no longer accurately reflect current road information.

The most accurate geometric information is now available in the latest release of the NCDOT Road Characteristics Arcs.

The latest Interstate diagrams are listed below in PDF format.

For additional historic and other current roadway information, including U.S. and N.C. route diagrams, contact Getaneh Admasu at (919) 835-8462.

By Interstate

I-26

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1002601 View Buncombe 0 Henderson 10.09 1965 - 1998
1002601A View Buncombe 0 Henderson 10.09 1997 - 2000
1002602 View Henderson 10.09 Polk 13.14 1965 - 2000

I-40

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1004001 View Haywood 0 Haywood 20 1959 - 1997
1004001A View Haywood 0 Haywood 20 1995 - 1998
1004002 View Haywood 20 Haywood 28 1974 - 1996
1004002A View Haywood 20 Haywood 28 1997 - 2001
1004003 View Haywood 27 Buncombe 10 1963 - 1996
1004003A View Haywood 27 Buncombe 10 1996 - 2001
1004004 View Buncombe 10 McDowell 0 1954 - 2000
1004005 View Buncombe 39.19 McDowell 5.33 1954 - 1999
1004006 View McDowell 5.33 McDowell 24 1960 - 1999
1004007 View McDowell 24 Burke 17.94 1956 - 2000
1004008 View Burke 17.94 Catawba 0 1956 - 2000
1004009 View Catawba 0 Catawba 10.89 1975 - 1998
1004010 View Catawba 10.89 Iredell 11.23 1953 - 1998
1004010A View Catawba 10.89 Iredell 11.23 1999
1004011 View Iredell 12 Davie 6.45 1953 - 1999
1004012 View Davie 6.45 Davie 17.31 1969 - 1993
1004013 View Davie 17.31 Forsyth 6.35 1959 - 1993
1004014 View Forsyth 6.35 Guilford 1.53 1990 - 2001
1004015 View Guilford 1.53 Guilford 10.53 1957 - 1997
1004015A View Guilford 1.53 Guilford 10.53 1998
1004016 View Guilford 10.53 Guilford 14.50 1957 - 1997
1004016A View Guilford 10.53 Guilford 14.50 1995 - 2000
1004017 View Guilford 14.19 Guilford 16.58 1953 - 1996
1004017A View Guilford 14.19 Guilford 16.58 1994 - 2000
1004018 View Guilford 16.58 Alamance 4 1953 - 1997
1004018A View Guilford 16.58 Alamance 4.73 1990 - 2000
1004019 View Alamance 4.73 Orange 7.45 1953 - 1995
1004019A View Alamance 4.73 Orange 7.45 1990 - 1993
1004020 View Orange 7.45 Orange 19.22 1987 - 1998
1004021 View Durham 0 Durham 9.36 1986 - 1998
1004022 View Durham 9.36 Wake 10 1961 - 1998
1004023 View Wake 10.81 Wake 20.80 1977 - 1999
1004024 View Wake 20.80 Wake 27.56 1986 - 1999
1004025 View Johnston 0 Johnston 19 1986 - 1999
1004026 View Johnston 19 Sampson 9 1988 - 2000
1004027 View Sampson 9 Duplin 8 1988 - 2000
1004028 View Duplin 8 Duplin 28 1986 - 2000
1004029 View Pender 0 Pender 20 1982 - 2002
1004030 View Pender 20 New Hanover 5.40 1983 - 2002

I-40 BUS

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1904001 View Forsyth 0 Guilford 2.17 1949 - 2001

I-73

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1007301 View Montgomery 0 Randolph 8.12 1964 - 1996

I-74

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1007401 View Surry 0 Surry 4 1975 - 1980
1007402 View Surry 4.5 Surry 17 1993 - 1998

I-77

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1007701 View Mecklenburg 0 Mecklenburg 12.50 1966 - 2000
1007702 View Mecklenburg 12.50 Mecklenburg 28.88 1975 - 2001
1007703 View Mecklenburg 27.88 Iredell 14.79 1962 - 1999
1007704 View Iredell 14.79 Iredell 34.85 1959 - 1995
1007705 View Iredell 34.85 Iredell 38.56 1973 - 1995
1007706 View Yadkin 0 Surry 2.97 1964 - 1998
1007707 View Surry 2.97 Surry 22.90 1974 - 1998

I-85

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1008501 View Cleveland 0 Gaston 11.85 1955 - 1996
1008501A View Cleveland 0 Gaston 11.85 1995 - 2001
1008502 View Gaston 11.85 Gaston 19 1961 - 1995
1008502A View Gaston 19 Mecklenburg 17.25 1996
1008503 View Gaston 19 Mecklenburg 17.25 1958 - 2001
1008503A View Gaston 19 Mecklenburg 17.25 1994
1008504 View Mecklenburg 17.25 Cabarrus 12.29 1968 - 2001
1008505 View Cabarrus 12.29 Rowan 6.36 1957 - 2001
1008506 View Rowan 6.36 Davidson 5 1940 - 2001
1008507 View Davidson 5.30 Randolph 0 1978 - 2000
1008508 View Randolph 0 Guilford 6.50 1981 - 2001
1008509 View Guilford 6.7 Guilford 11.65 1955 - 1997
1008509A View Guilford 6.7 Guilford 11.65 1997
1008510 View Orange 0 Orange 1.21 1960 - 1988
1008511 View Orange 1.21 Durham 13.20 1942 - 1977
1008512 View Durham 13.20 Granville 19 1954 - 1999
1008512A View Durham 13.20 Granville 19 1995 - 1998
1008513 View Granville 19 Vance 6 1954 - 1998
1008514 View Vance 7 Warren 10.64 1959 - 1999

I-95

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1009501 View Robeson 0 Robeson 20 1955 - 1997
1009502 View Robeson 20 Cumberland 1.30 1955 - 2000
1009503 View Cumberland 1.32 Cumberland 17.5 1960 - 2000
1009504 View Cumberland 17.5 Harnett 6.95 1955 - 1995
1009504A View Cumberland 17.5 Harnett 6.95 1998
1009505 View Harnett 7 Johnston 18.15 1955 - 1995
1009505A View Harnett 7 Johnston 18.15 1985 - 1995
1009506 View Johnston 18.15 Wilson 7.75 1957 - 1996
1009506A View Johnston 18.15 Wilson 7.75 1993 - 2001
1009507 View Wilson 7.75 Nash 11.35 1977 - 1994
1009508 View Nash 11.45 Nash 20 1978 - 1983
1009509 View Nash 19.50 Halifax 13 1966 - 1993
1009510 View Halifax 14 Northampton 7.55 1960 - 1999

I-95 BUS

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1909501 View Cumberland 0 Cumberland 16 1957 - 1988
1909502 View Nash 0 Nash 5 1967 - 1991

I-240

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1024001 View Buncombe 0 Buncombe 10 1950 - 1991
1024001A View Buncombe 0 Buncombe 10 1993 - 2001

I-277

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1027701 View Mecklenburg 0 Mecklenburg 5 1970 - 1989

I-440

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1044001 View Wake 0 Wake 16 1962 - 1991
1044001A View Wake 0 Wake 16 1993 - 2000

I-540

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1054001 View Durham I-40 Wake Creedmoor Rd. 1997 - 2001

I-485

Straight Line Diagram From County County Milepost To County County Milepost Project Completion Date Range
1048501 View Mecklenburg SR-1143 Mecklenburg US-521 1993 - 2001
1048502 View Mecklenburg ? Mecklenburg approx 1 mi W of Providence Road 1991 - 2001
1048503 View Mecklenburg ? Mecklenburg ? 1997 - 2001