Dwight D. Eisenhower National System of Interstate and Defense Highways
Highway shields for Interstate 35E and Interstate 69W
The 1958 Interstate Highway System plan included many suffixed Interstates.
System information
Formed	June 29, 1956[1]
Highway names
Interstates	Interstate X (I-X)
System links
Interstate Highway System Main Auxiliary Suffixed Business Future

In the United States, there are currently eight routes in theInterstate Highway System that are signed with letter suffixes to the route number.Interstate 35 (I-35) splits intoI-35E andI-35W in theDallas–Fort Worth metroplex in Texas, and similarly splits intoI-35E andI-35W in theMinneapolis–St. Paul area in Minnesota. Other suffixed Interstates includeI-69C,I-69E andI-69W inSouth Texas, andI-480N in Ohio, which is designated as such on mile markers but is otherwise unsigned. The state ofMaryland has four unsigned suffixed Interstate designations that are designated by theMaryland State Highway Administration, rather than by theFederal Highway Administration (FHWA).

There were once many more suffixed Interstates, as thethree-digit Interstates were not designated until after all major routes were assigned numbers. Most of these were spurs; the suffixed route did not return to its parent. In 1980, theAmerican Association of State Highway and Transportation Officials (AASHTO) abolished the majority of suffixes due to confusion, renumbering them as three-digit Interstates. For example,I-15E in California has since becomeI-215.

Number	Length (mi)	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed	Notes
I-5W	—	—	I-5 inTracy, CA	I-5 inDunnigan, CA	—	—	Replaced byI-580,I-80 andI-505
I-5E	—	—	I-5 inTracy, CA	I-5 inDunnigan, CA	01958-01-011958	01982-01-011982	Replaced by I-5
I-15E	—	—	I-15 inTemecula, CA	I-15 inDevore, CA	01973-01-011973	01982-01-011982	Renumbered fromI-215 in 1973 and back to I-215 in 1982
I-15W	—	—	I-15 inMurrieta, CA	I-15 inSan Bernardino, CA	01957-01-011957	—	BecameI-15 in 1957
I-15W	—	—	I-80N inRupert, ID	I-15 inPocatello, ID	01958-01-011958	01980-01-011980	BecameI-86 in 1980; was also planned asI-82N
I-24W	—	—	I-55 inHayti, MO	I-40 inJackson, TN	—	01964-01-011964	Did not connect toI-24; renumberedI-155
I-35W	85.20	137.12	I-35 inHillsboro, TX	I-35 inDenton, TX	01959-01-011959	current
I-35E	96.76	155.72	I-35 inHillsboro, TX	I-35 inDenton, TX	01959-01-011959	current
I-35W	—	—	I-35 inWichita, KS	I-70 inSalina, Kansas	—	01976-01-011976[2]	RenumberedI-135[2]
I-35W	41.78	67.24	I-35 inBurnsville, MN	I-35 inForest Lake, MN	01960-01-011960	current
I-35E	39.34	63.31	I-35 inBurnsville, MN	I-35 inForest Lake, MN	01970-01-011970	current	Trucks over 9,000 lb (4,100 kg) gross weight prohibited between MN 5 and I-94
I-59B	—	—	Bypass forI-59 aroundBirmingham, AL		—	—	RenumberedI-459
I-69W	1.43	2.30	Fed. 85D atMexican border onWorld Trade International Bridge atLaredo, TX	US 59/Loop 20 in Laredo, TX	02014-01-012014	current	Partially completed
I-69C	18.02	29.00	I-2/US 83/US 281 inPharr, TX	US 281/FM 490 inEdinburg, TX	02013-01-012013	current	Partially completed
I-69E	81.00	130.36	East Rio Grande Valley segment:US 77/US 83/University Boulevard inBrownsville, TX Corpus Christi area segment:US 77 inKingsville, TX	East Rio Grande Valley segment:US 77 nearRaymondville, TX Corpus Christi area segment:I-37/US 77 inCorpus Christi, TX	02011-01-012011	current	Partially completed
I-70S	—	—	I-70 inWashington, PA	I-70/I-80S inNew Stanton, PA	01958-01-011958	01964-01-011964	Became part of I-70 and former I-70 became parts ofI-79 andI-76
I-70N	—	—	I-70 inFrederick, MD	I-83/I-95 inBaltimore, MD	01958-01-011958	01973-01-011973	BecameI-70
I-70S	—	—	I-70 inFrederick, MD	I-66/I-95 inWashington, DC	01958-01-011958	01973-01-011973	BecameI-270
I-75E	—	—	Bypass forI-75 aroundTampa-St. Petersburg, FL		—	01973-01-011973	RenumberedI-275; later swapped with I-75 in 1973
I-80N	—	—	I-5 inPortland, OR	I-80 inEcho, UT	01958-01-011958	01980-01-011980	BecameI-84
I-80S	—	—	I-25/I-70 inDenver, CO	I-80 inBig Springs, NE	01958-01-011958	01980-01-011980	BecameI-76
I-80N	—	—	I-80 inNeola, IA	I-29 inLoveland, IA	—	01973-01-011973	Became part ofI-680, thenI-880 after I-680 was split
I-80N	—	—	I-80/I-90 inLorain County, OH	I-80S/SR 5 inBraceville Township, OH	01960-01-011960	01962-01-011962	Redesignated as I-80
I-80S	—	—	I-80 inYoungstown, OH	I-295 inCamden, NJ	—	01970-01-011970	Extended west toLodi, OH, by 1962 over former I-80; east end truncated toMonroeville, PA, and the part east of Monroeville renumberedI-76 in 1964; the rest became part of I-76
I-81S	—	—	I-81 inScranton, PA	I-80 at Crescent Lake	—	01964-01-011964	Formerly I-82, became I-81E (now I-380)
I-81E	—	—	I-81 inScranton, PA	I-80 inScotrun, PA	01964-01-011964	01973-01-011973	Formerly I-81S, became I-380
I-82S	—	—	Burley, ID	Tremonton, UT	01957-01-011957	—	BecameI-84
I-82N	—	—	Burley, ID	Pocatello, ID	01957-01-011957	—	BecameI-86
I-90N	—	—	Buffalo, NY	Canadian border atLewiston, NY	01957-01-011957	01959-01-011959	Original designation for I-190 in New York, renamed I-190
I-94N	—	—	Muskegon, MI	I-94 inGrand Rapids, MI	01957-01-011957	01959-01-011959	BecameI-196 in 1959[3] and thenI-96 in 1964[4]
I-95E	—	—	East Providence, RI	-	01957-01-011957	01959-01-011959	RenumberedI-195
I-180N	—	—	I-80N	Boise, ID	—	01980-01-011980	This was the only suffixed three-digit Interstate (until I-480N in Ohio was designated); all other spurs of suffixed routes had no suffix; becameI-184
I-270Y	2.10[5]	3.38	I-270 inBethesda, MD	I-495 inBethesda, MD	01975-01-011975	current	Signed as I-270 Spur; designated internally by MDSHA asI-270Y.
I-480N	1.99[6]	3.20	I-480 inMaple Heights, OH	US 422 inWarrensville Heights, OH	01974-01-011974	current	Signed as I-480 on guide signs and reassurance markers, signed as I-480N on mile markers
I-495X	1.50[5]	2.41	I-495 inBethesda, MD	Clara Barton Parkway inCabin John, MD	01965-01-011965	current	Also known asCabin John Parkway; designated internally by MDSHA as I-495X; unsigned; trucks are not allowed on the length of the freeway
I-895A	0.71[5]	1.14	I-895B inBrooklyn Park, MD	I-97 inFerndale, MD	01965-01-011965	current	Unsigned. Internally designated by MDSHA as I-895A
I-895B	2.67[5]	4.30	I-895 inBrooklyn Park, MD	Governor Ritchie Highway inGlen Burnie, MD	01965-01-011965	current	Unsigned. Internally designated by MDSHA as I-895B
Former

• U.S. Roads portal
• List of divided U.S. Routes

• Kirby, J.P.; et al."Frequently Asked Questions - What are/where all the suffixed Interstates?".misc.transport.road.

• Interstate Highway System
• Lists of Interstate Highways

• Articles with short description
• Short description is different from Wikidata
• Use American English from July 2025
• All Wikipedia articles written in American English
• Use mdy dates from August 2016