View source for List of gaps in Interstate Highways

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{{Original research|date=December 2024}}
{{Use mdy dates|date=March 2025}}
{{infobox state highway system
|title= Dwight D. Eisenhower National System of Interstate and Defense Highways
|shields={{infobox road/shieldmain/USA|type=I|route=69}} {{infobox road/shieldmain/USA|type=I|route=70}}
|caption=[[Highway shield]]s for Interstate&nbsp;69 and Interstate&nbsp;70, highways with true gaps and freeway gaps
|map=Map of current Interstates.svg
|map_alt=
|map_notes=Interstate Highways in the 48&nbsp;contiguous states
|formed= June 29, 1956<ref name=FAHA56>{{cite journal |last = Weingroff |first = Richard F. |title = Federal-Aid Highway Act of 1956, Creating the Interstate System |url = https://highways.dot.gov/public-roads/summer-1996/federal-aid-highway-act-1956-creating-interstate-system |journal = Public Roads |location = Washington, DC |publisher = [[Federal Highway Administration]] |volume = 60 |issue = 1 |date = Summer 1996 |access-date = March 16, 2012 }}</ref>
|length_mi=
|length_ref=
|interstate=Interstate X (I-X)
|us=
|state=
|notes=
|links=I
}}
[[File:Breezewood, Pennsylvania.jpg|thumb|right|I-70 briefly follows an at-grade portion of US 30 with traffic lights in Breezewood, Pennsylvania]]
There are gaps in the [[Interstate Highway System]] where the roadway carrying an Interstate shield does not conform to the [[Interstate Highway standards|standards]] set by the [[Federal Highway Administration]] (FHWA), the body that sets the regulations for the Interstate Highway System. For the most part, the Interstate Highway System in the [[United States]] is a connected system, with most freeways completed; however, some Interstates still have gaps. These gaps can be due to unconnected segments of the same route or from failure of the road to fully conform to Interstate standards by including such characteristics as at-grade crossings, traffic lights, undivided or narrow freeways, or movable bridges ([[vertical lift bridge|lift bridges]] and [[bascule bridge|drawbridges]]).

==True gaps==
True gaps are where multiple disjoint sections of road have the same Interstate highway number and can reasonably be considered part of "one highway" in theory, based on the directness of connections via other highways, or based on future plans to fill in the gap in the Interstate, or simply based on the shortness of the gap. The sections are either not physically connected at all, or they are connected but the connection is not signed as part of the highway. This list does not include different highways that share the same number, such as the two different [[Interstate 84 (disambiguation)|I-84s]] and [[Interstate 87 (disambiguation)|I-87s]], which despite appearances, were always intended as distinct highways and were never intended as a contiguous route.

===Interstate 26===
In North Carolina, [[Interstate 26]] has a gap from Forks of Ivy to Asheville at exit 4A of Interstate 240. This is because not all of the parts in the gap were built to Interstate standards. As of May 2025, [[Interstate 26 in North Carolina|Interstate 26]] is designated as Future I-26, [[U.S. Route 19 in North Carolina|US 19]], and [[U.S. Route 23 in North Carolina|US 23]], as well as a section also being concurrent with [[U.S. Route 25 in North Carolina|US 25]] and [[U.S. Route 70 in North Carolina|US 70]]. In an effort to build the gap to Interstate standards, construction of the overall "Asheville I-26 Connector" project started in the summer of 2024 and is expected to be completed no earlier than October 2031.<ref>{{Cite web |url = https://www.ncdot.gov/projects/asheville-i-26-connector/Pages/default.aspx |title = NCDOT: Asheville I-26 Connector |publisher = North Carolina Department of Transportation |accessdate = January 19, 2022 }}</ref>

===Interstate 42===
In North Carolina, [[Interstate 42]] has a gap from Clayton to Goldsboro. This is because the corridor that the Interstate will be on is not up to standards or is unbuilt.{{cn|date=September 2024}} North Carolina plans to complete I-42 entirely by 2032.{{cn|date=September 2024}}

===Interstate 49===
[[Interstate 49]] (I-49) currently has three sections: the original alignment from I-10 in [[Lafayette, Louisiana|Lafayette]] to I-20 in [[Shreveport]], one from [[Interstate 220 (Louisiana)|I-220]] near Shreveport to [[Texarkana, Arkansas|Texarkana]]; and the third section from I-40 near [[Alma, Arkansas]] to I-470/I-435 south of [[Kansas City, Missouri]]. A bypass south of [[Bella Vista, Arkansas]] was completed in 2021, and existed initially as [[Arkansas Highway 549]]; the latter designation is now used on a short section southeast of [[Fort Smith, Arkansas|Fort Smith]] that is several miles long. It is planned to be connected to an interstate with a project to construct a new roadway from Arkansas Highway 22 to Interstate 40 in Arkansas. I-49 from Fort Smith to Texarkana is still unbuilt. These gaps are expected to be eventually closed.

===Interstate 57===
Since November 7, 2024, [[Interstate 57]] currently has two sections: the original alignment from [[Interstate 55 in Missouri|Interstate 55]] in [[Sikeston, Missouri]], to [[Interstate 94 in Illinois|Interstate 94]] in [[Chicago|Chicago, Illinois]], and another section from [[Interstate 40 in Arkansas|Interstate 40]] in [[North Little Rock, Arkansas]], to [[U.S. Route 67 in Arkansas|U.S. Route 67]] and [[U.S. Route 412 in Arkansas|U.S. Route 412]] in [[Walnut Ridge, Arkansas]].<ref>{{Cite news |title = Arkansas to celebrate U.S. Highway 67’s designation as Interstate 57 on Thursday |url = https://www.whiterivernow.com/2024/11/02/arkansas-to-celebrate-u-s-highway-67s-designation-as-interstate-57-on-thursday/ |date = November 2, 2024 |access-date = November 7, 2024 |website = White River Now |location = Batesville, Arkansas |language = en-US }}</ref> The latter section is part of an unfinished southern extension of Interstate 57 that will extend the route to North Little Rock. Construction is currently underway on bridging the gap and making Interstate 57 continuous again.<ref>{{Cite web |last = Arkansas Department of Transportation |date = October 25, 2023 |title = Future Interstate 57 Alignment from Walnut Ridge to Missouri State Line Chosen |url = https://www.ardot.gov/news/23-365/ |access-date = November 13, 2024 |publisher = Arkansas Department of Transportation }}</ref>

===Interstate 69===
[[Interstate 69|I-69]] currently has several disconnected segments: the northernmost segment travels from near [[Evansville, Indiana]], to [[Port Huron, Michigan]]. A second alignment located entirely within the state of Kentucky runs from the Tennessee state line at [[Fulton, Kentucky|Fulton]] to [[Henderson, Kentucky|Henderson]]. On October 2, 2006, a segment of I-69 opened in [[Tunica County, Mississippi|Tunica]] and [[DeSoto County, Mississippi|DeSoto]] counties in Mississippi; this segment has since been continued (but is not signed) through [[Memphis, Tennessee]], to an intersection with [[U.S. Route 51|U.S. Highway 51]] on the north side. Between 2012 and 2015, a portion of [[U.S. Route 59|U.S. Highway 59]] (US&nbsp;59) between [[Rosenberg, Texas|Rosenberg]] and [[Cleveland, Texas]], extending through [[Houston]], became part of I-69.<ref>{{AASHTO minutes|year=2012S}}</ref><ref>{{cite web |date = February 28, 2013 |title = Alliance for I-69 Texas: More Houston Areas Freeway Added to Interstate 69 |url = http://www.i69texasalliance.com/NewsUpdates/update2.28.13.html |publisher = Alliance for I-69 Texas }}</ref><ref>{{cite web |date = March 26, 2015 |title = Texas Transportation Commission Minute Order |url = http://ftp.dot.state.tx.us/pub/txdot/commission/2015/0326/5.pdf |publisher = Texas Transportation Commission }}</ref> In South Texas, I-69's route splits into three spurs to cities on the U.S.–Mexico border, on which four segments are complete: a short segment of I-69E in [[Corpus Christi, Texas|Corpus Christi]] and another from [[Raymondville, Texas|Raymondville]] to the border in [[Brownsville, Texas|Brownsville]]; a short segment of I-69C in [[Edinburg, Texas|Edinburg]] and [[McAllen]]; and a very short segment of I-69W adjacent to the border in [[Laredo, Texas|Laredo]].

As of 2025, projects to connect these segments are in varying stages of development. Kentucky and Indiana began construction of the eastern bypass of Henderson and new [[Interstate 69 Ohio River Crossing|Ohio River Crossing]], connecting the Kentucky and Indiana sections, in 2022.<ref>{{Cite web |title = Ohio River Crossing: ORX Section 1 |url = https://i69ohiorivercrossing.com/orx-section-1/ |access-date = December 30, 2021 |website = I-69 Ohio River Crossing |publisher = [[Indiana Department of Transportation]] and [[Kentucky Transportation Cabinet]] }}</ref> This segment has a tentative completion date of 2031.<ref>[https://i69ohiorivercrossing.com/section-2-i-69-bridge/ Section 2: I-69 Bridge, I-69 Ohio River Crossing (Official Project Website)]</ref> Kentucky has plans to work with Tennessee to reconstruct the current interchange at the south end of their segment in [[South Fulton, Tennessee|South Fulton]] to provide a free-flow connection to the existing US&nbsp;51 freeway to Union City. Tennessee finished constructing a bypass of [[Union City, Tennessee|Union City]] in 2021 currently designated as SR&nbsp;690.<ref>{{Cite web |last = Latham |first = Angele |date = July 15, 2021 |title = Interstate 69 Bypass, part of 'last great American highway,' kicks off paving in Obion County |url = https://www.jacksonsun.com/story/news/2021/07/16/paving-interstate-69-bypass-obion-county-tennessee/7937940002/ |access-date = December 31, 2021 |website = The Jackson Sun |language = en-US }}</ref> A further bypass of [[Troy, Tennessee|Troy]] is proposed but not yet funded, which would complete a freeway-standard route from [[Interstate 155 (Missouri–Tennessee)|I-155]] in [[Dyersburg, Tennessee|Dyersburg]] to Henderson. Tennessee has deferred plans to complete the section between Dyersburg and Memphis to close the gap until the South Fulton–Dyersburg section is completed.<ref>{{Cite web |last = Irel |first = Jeff |date = January 19, 2021 |title = Updates on Interstate 69, Highway 14, an east-west corridor and the Megasite |url = https://covingtonleader.com/news/updates-on-interstate-69-highway-14-an-east-west-corridor-and-the-megasite/ |access-date = December 31, 2021 |website = The Leader |location = Covington, Tennessee |language = en-US }}</ref> The section from Memphis to Houston is the least developed; as of 2021, Mississippi has no current plans to extend I-69 further south, and the states of Louisiana and Arkansas have not funded construction of their portion of the proposed route (via [[El Dorado, Arkansas|El Dorado]] and [[Shreveport]]) between Mississippi and Texas, other than a two-lane southern bypass of [[Monticello, Arkansas]] designed to be incorporated into I-69 at a later date. Texas has continued to fund projects to upgrade U.S. 59, U.S. 77, U.S. 281, and other routes that would eventually form parts of I-69 in South Texas and East Texas, including the I-69W/C/E spurs.

===Interstate 74===
[[Interstate 74|I-74]] currently has five sections,<ref>{{cite web |first = Bob |last = Malme |url = http://www.duke.edu/~rmalme/prog74.html |title = I-74 North Carolina Progress Page |access-date = August 28, 2009 |url-status = dead |archive-url = https://web.archive.org/web/20100725101324/http://www.duke.edu/~rmalme/prog74.html |archive-date = July 25, 2010 }}{{sps|certain=y|date=August 2012}}</ref> the original segment heading northwest from [[Cincinnati|Cincinnati, Ohio]], to [[Davenport, Iowa]]; one from the [[Virginia]]–[[North Carolina]] line along [[Interstate 77|I-77]] south and east to a point southeast of [[Mount Airy, North Carolina]]; one traveling around [[High Point, North Carolina|High Point]] connecting with [[Interstate 85|I-85]] and reaching [[Interstate 73|I-73]], where the two are concurrent until Ellerbe; and from west of [[Laurinburg, North Carolina|Laurinburg]] to south of [[Lumberton, North Carolina]], at [[Interstate 95|I-95]]. [[North Carolina]] is currently{{when?|date=May 2023}} working on connecting all its sections of I-74.

===Interstate 86 (Eastern)===
The eastern [[Interstate 86 (Pennsylvania–New York)|I-86]] has had two sections since 2006. One travels for {{convert|197|mi}} from [[Interstate 90|I-90]] in [[North East Township, Erie County, Pennsylvania|North East, Pennsylvania]] (which is a town in the northwestern part of the state) to exit&nbsp;61 in [[Waverly, Tioga County, New York|Waverly, New York]]. The second section is a {{convert|9.9|mi|km|adj=on}} stretch outside of [[Binghamton, New York|Binghamton]] traveling from [[Interstate 81|I-81]] in [[Kirkwood, New York|Kirkwood]] to exit&nbsp;79 in [[Windsor (village), New York|Windsor]]. The gap is signed as [[Interstate 86 (Pennsylvania–New York)#Future|Future 86]]. I-86 will eventually travel from North East, Pennsylvania, to the [[New York State Thruway]] ([[Interstate 87 (New York)|I-87]]) near [[Harriman, New York]]. All the designated sections and gaps in New York are part of [[New York State Route&nbsp;17]].

===Interstate 99===
As of 2023, [[Interstate 99|I-99]] has two sections: one from the [[Pennsylvania Turnpike]] in [[Bedford, Pennsylvania|Bedford]] to [[Interstate 80 in Pennsylvania|I-80]] near [[Bellefonte, Pennsylvania|Bellefonte]], concurrent with [[U.S. Route 220|US&nbsp;220]], and one from the Pennsylvania–New York state line north to [[Interstate 86 (Pennsylvania–New York)|I-86]] in [[Corning (city), New York|Corning]], concurrent with [[U.S. Route 15|US&nbsp;15]]. Much of the intervening route, including the entire US 15 section between [[Interstate 180 (Pennsylvania)|I-180]] in [[Williamsport, Pennsylvania|Williamsport]] and the New York state line, has been constructed to freeway standards but as of yet is not signed as part of I-99.

The signing of the intervening route as I-99 will be completed when the route is upgraded to Interstate standards, connecting the two segments of I-99.

===Interstate 695===
When the [[Francis Scott Key Bridge (Baltimore)|Francis Scott Key Bridge]] in [[Baltimore]], Maryland, [[Francis Scott Key Bridge collapse|collapsed]] in March 2024, a segment of [[Interstate 695 (Maryland)|I-695]] would physically disappear for some time as a consequence of the bridge collapse.<ref name="Associated Press2">{{cite news |last = Skene |first = Lea |date = March 26, 2024 |title = Francis Scott Key Bridge in Baltimore collapses after ship struck it, sending vehicles into water |url = https://apnews.com/article/baltimore-bridge-collapse-53169b379820032f832de4016c655d1b |url-status = live |archive-url = https://web.archive.org/web/20240326110240/https://apnews.com/article/baltimore-bridge-collapse-53169b379820032f832de4016c655d1b |archive-date = March 26, 2024 |access-date = March 26, 2024 |work = [[AP News]] }}</ref> At the time of the collapse, the section of highway was legally Maryland Route 695, but this section was redesignated as I-695 by the [[American Association of State Highway and Transportation Officials]] in April 2024.<ref>{{AASHTO minutes |year = 2024S |access-date = June 7, 2024 }}</ref>

==Freeway gaps==
Freeway gaps occur where the Interstate is signed as a continuous route, but part, if not all of it, is not up to [[controlled-access highway|freeway]] standards. This includes [[drawbridge]]s where traffic on the Interstate can be stopped for vessels. This does not include facilities such as [[toll road|tollbooths]], toll plazas, agricultural inspection stations, or [[border checkpoint|border stations]].

===At-grade intersections===
====Major at-grade intersections====
[[File:I-78 Feeding Holland Tunnel jeh.jpg|thumb|Surface street section of I-78 in Jersey City, New Jersey]]

In urban and heavily developed areas, Interstates may travel along surface roads or have [[at-grade intersection]]s with stop signs or traffic lights. This usually happens because the Interstate started construction after the land was heavily developed and buildings such as residences and businesses and other roads would have to be removed to allow a freeway to pass through. Additionally, more developed land would have to be cleared for space to build interchanges to connect the Interstate and surface streets. This situation is extremely uncommon as Interstates are usually built around cities or through them on pre- or lightly developed land.

* [[Interstate 516|I-516]] downgrades to an expressway as it heads toward its eastern terminus. The expressway features a frontage road right turn and an at-grade intersection with Mildred Street close to the terminus at Montgomery Street and Derenne Avenue ([[Georgia State Route 21|SR 21]]) in [[Savannah, Georgia]]. Mildred Street southbound is closed by concrete barriers.
* [[Interstate 19|I-19]] between North West Street and its southern terminus at West Crawford Street at North Sonoita Avenue, in [[Nogales, Arizona]], consists of surface streets with traffic lights. The signage of this segment is intended to help direct traffic entering from Mexico to the nearest interstate.
* [[Interstate 69E|I-69E]] in [[Brownsville, Texas]] passes through an at-grade signalized intersection with University Boulevard, as well as a minor intersection with Courage Street, before passing through the [[Brownsville – Veterans Port of Entry]] and crossing the [[Veterans International Bridge at Los Tomates|Veterans International Bridge]].
* [[Interstate 169 (Texas)|I-169]] in [[Brownsville, Texas]] is a divided frontage road with no parts built to Interstate standard; it runs parallel to the SH 550 Toll [[Limited-access road|expressway]] and consists of a single 4-way stop intersection, a railroad crossing, and four traffic lights, two on each side. I-169 signage ends slightly east of Paredes Line Road to where the frontage road ends, approximately 4.1 miles from the I-69E interchange. The remaining portion of I-169, which ends at SH 48, is unsigned and has a 2-lane, limited-access toll-only segment starting from where FM 511 diverges.
* {{anchor|I70 Breezewood}}[[Interstate 70 in Pennsylvania|I-70]] uses part of [[U.S. Route 30 in Pennsylvania|US 30]] along a surface road in [[Breezewood, Pennsylvania]], at the eastern end of its concurrency with [[Interstate 76 (Ohio-New Jersey)|I-76]] on the [[Pennsylvania Turnpike]]. Traffic traveling eastbound on the turnpike must exit and travel a short distance on US 30 in order to continue south on I-70 heading to [[Hancock, Maryland]]. (The routing is similar for traffic following I-70 in the opposite direction: traffic traveling north on I-70 must exit and travel a short distance on US 30 in order to enter the turnpike.) This is one of very few instances of [[traffic light]]s on an Interstate. It was constructed this way because the original Interstate Highways act did not fund direct connections between an Interstate and a tolled road. There was formerly a sign of a policeman pointing at drivers leaving the Pennsylvania Turnpike to enter US 30, saying, "You! Slow Down!" Local businesses have lobbied to keep the gap to avoid a perceived potential loss of business.<ref>{{cite news |first = Manuel |last = Roig-Franzia |title = The Town That Stops Traffic: Travelers Encounter Way Station as Way of Life in Breezewood |newspaper = [[The Washington Post]] |date = November 22, 2001 |page = B1 |url-access = subscription |url = https://www.proquest.com/docview/409173468 |id = {{ProQuest|409173468}} }}</ref> Despite this, the Pennsylvania Turnpike has announced plans to close this gap by directly connecting I-70 to the Turnpike in September 2024.<ref>{{Cite web |title = PA Turnpike to Redesign Breezewood Interchange with a Connection to Interstate 70 |url = https://www.paturnpike.com/news/details/2024/09/24/pa-turnpike-to-redesign-breezewood-interchange-with-a-connection-to-interstate-70 |access-date = September 27, 2024 |publisher = Pennsylvania Turnpike Commission |language = en }}</ref> Completion of the construction is expected in 8-10 years.<ref>{{Cite web |title = PA Turnpike Selects Designer for Breezewood Interchange Project |url = https://www.paturnpike.com/news/details/2025/02/20/pa-turnpike-selects-designer-for-breezewood-interchange-project |access-date = March 30, 2025 |publisher = Pennsylvania Turnpike Commission |language = en }}</ref>
* [[Interstate 676|I-676]] has a surface street section at the west end of the [[Ben Franklin Bridge]] in [[Philadelphia|Philadelphia, Pennsylvania]], because of historically significant areas. Signage and the [[Federal Highway Administration]] consider I-676 to use the surface streets; the [[Pennsylvania Department of Transportation]] and the [[New Jersey Department of Transportation]] consider I-676 to be continuous across the [[Ben Franklin Bridge]], even though the bridge, built in 1926, is not up to Interstate standards. This does not specifically violate Interstate standards, however, as the two separated segments of I-676 are in different states.
* [[Interstate 78|I-78]] travels along a [[one-way pair]] of surface streets, 12th Street and 14th Street, in [[Jersey City, New Jersey]], between the end of the [[New Jersey Turnpike]] Newark Bay Extension and the [[Holland Tunnel]], which leads into [[New York City]]. Between the two aforementioned points are four signalized intersections.<ref>{{google maps |url = https://maps.google.com/maps?q=Jersey+City+NJ&t=h&ie=UTF8&ll=40.731861,-74.042729&spn=0.001785,0.004828&z=18&layer=c&cbll=40.731839,-74.042516&panoid=5dvrrt9-DUeW4FQkik1ltg&cbp=12,273.3558391375674,,0,3.999999999999998 |title = Intersection of 14th St (ostensibly 78 West) and Erie St  |access-date = August 28, 2009 }}</ref>
* [[Interstate 180 (Wyoming)|I-180]] in [[Cheyenne, Wyoming]] is an [[Limited-access road|expressway]] with no parts built to Interstate standard; the interchange with [[Interstate 80 in Wyoming|I-80]] is a simple [[diamond interchange]] with two traffic lights on I-180.
* [[Interstate 81 in New York|I-81]] near [[Alexandria, New York]] before the [[Thousand Islands Bridge]] across the [[Saint Lawrence River]] has intersections with an off-ramp leading from [[New York State Route 12|NY-12]] and a service road connecting from the bridge toll station to a police department while also intersecting NY-12.
* [[Interstate 587 (New York)|I-587]] in [[Kingston, New York]], has a [[traffic circle]] (with yield signs) at its northern terminus with the ramps leading to/from [[Interstate 87 (New York)|I-87]].

====Minor at-grade intersections====
Several Interstates in rural areas of the U.S. have minor [[at-grade intersection]]s (including median breaks) with farm access roads or authorized vehicle-only driveways used for highway maintenance or connection to nearby utility stations. This is usually due to the lack of an old highway, the need to provide access to property that was accessed via the road prior to its upgrade to an Interstate, and the high cost to construct an interchange for the small amount of traffic that would use such a connection or to build a [[frontage road]] parallel to the freeway to the nearest interchange.

* The northbound lanes of [[Interstate 5 in Washington|I-5]] in Washington intersect with an at-level [[Pedestrian crossing|crosswalk]] approximately {{convert|100|ft|m}} south of the [[Canada–United States border|border with Canada]]. This crosswalk allows pedestrians access to a monument that is part of [[Peace Arch Park]].
* [[Interstate 10|I-10]] in [[Hudspeth County, Texas]] has at least fifteen at-grade intersections containing median breaks with minor dirt or gravel roads.
* [[Interstate 520|I-520]] in [[Augusta, Georgia]] has an at-grade intersection with a gravel and asphalt road that provides access to Lovers Lane.
* [[Interstate 40 in North Carolina|I-40]] in the mountains of western [[North Carolina]] has at-grade access to several dirt roads, as well as a partially grade-separated interchange that lacks ramps or [[Right-in/right-out|RIROs]] where roads directly connect to the I-40 carriageways.
* [[Interstate 40 in Texas|I-40]] in western [[Texas]] has eight at-grade access points for cattle ranches with median breaks.
* [[Interstate 94 in Michigan|I-94]] at [[Fort Custer Training Center|Fort Custer]] west of [[Battle Creek, Michigan]] is the only instance of an Interstate freeway in Michigan to have a gated driveway (at 44th Street), which facilitates access of [[military vehicle]]s.<ref>{{cite web |author = Michigan Department of Transportation |author-link = Michigan Department of Transportation |date = n.d. |url = http://www.michigan.gov/mdot/0,4616,7-151-9620_11154-129683--,00.html |title = Road & Highway Facts |publisher = Michigan Department of Transportation |access-date = October 28, 2014 }}</ref>

===Undivided and narrow freeways===
[[File:I-93 Franconia Notch.jpg|thumb|right|Two-lane stretch of I-93 through Franconia Notch in New Hampshire]]
[[File:Thousand Islands Bridge.jpg|thumb|right|Two-lane stretch of I-81 on the Thousand Islands Bridge crossing part of the Saint Lawrence River]]
[[File:Mackinac Bridge.JPG|thumb|right|The Mackinac Bridge, which carries I-75, has no hard shoulders, and has only a {{convert|4|in|cm|adj=mid|-tall}} divider between the opposing directions]]

This section addresses [[two-lane freeway]]s and other narrow or undivided freeway sections of the Interstate, excepting instances of continuing routes using one-lane ramps and merge leads. Narrow gaps between opposing directions with jersey barriers taller than {{convert|4|ft|m|spell=in}} are excluded from this section; therefore the separation criterion is either a {{convert|4|ft|m|adj=mid|-tall}} wall, or a {{convert|100|ft|m|adj=mid|-wide}} median, whichever is greater.
* [[Interstate 335 (Oklahoma)|I-335]] in [[Oklahoma]] is a two-lane, undivided turnpike roadway with a length of {{cvt|0.7|mi|km}}, starting from the [[Interstate 40 in Oklahoma|I-40]] junction and ending at the SE 89th Street intersection, continuing south as McDonald Road.
* [[Interstate 40 in North Carolina|I-40]]'s western {{convert|15|mi|km}} in [[North Carolina]] in the [[Harmon Den Wildlife Management Area]] has several S-curves, a Jersey barrier with extremely narrow left shoulders and a few at-grade intersections albeit in [[RIRO expressway|RIRO style]].
* [[Interstate 555|I-555]] at its southern terminus through the I-55/[[U.S. Route 61|U.S. 61]]/[[Arkansas Highway 77|AR 77]] interchange becomes a two-lane undivided highway for {{cvt|0.34|mi|km}}.
* [[Interstate 70]] is one-lane only in these following locations:
**[[Interstate 70 in Kansas]] has only one lane for eastbound through traffic for several hundred feet in [[Kansas City, Kansas|Kansas City]] where the highway approaches the [[Intercity Viaduct|Lewis and Clark Viaduct Bridge]], which carries the highway over the [[Kansas River]] toward [[Kansas City, Missouri]]. [[Interstate 670 (Kansas–Missouri)|Interstate 670]], just a few blocks south provides an alternate route without this bottleneck.
** [[Interstate 70 in West Virginia]] has only one lane for approximately one thousand feet in [[Wheeling, West Virginia|Wheeling]],<ref>{{google maps |url = https://www.google.com/maps/dir/40.0720684,-80.7258906/40.0723382,-80.7224505/@40.072251,-80.7247183,222m/data=!3m2!1e3!4b1!4m2!4m1!3e0?hl=en |title=North America to 870 I-70 |access-date = April 15, 2021 }}</ref> where the highway enters the [[Wheeling Tunnel]] and crosses the [[Ohio River]] on the [[Fort Henry Bridge]]. Nearby [[Interstate 470 (Ohio-West Virginia)|I-470]] provides relief from this situation.
* The [[Mackinac Bridge]], which carries [[Interstate 75 in Michigan|I-75]] over the [[Straits of Mackinac]] between [[St. Ignace, Michigan|St. Ignace]] and [[Mackinaw City, Michigan|Mackinaw City]], Michigan, has no wide median or hard shoulders due to space constraints. Nor does it have a [[Jersey barrier]]; instead, it has either a {{convert|4|in|cm|adj=mid|-tall}} yellow divider between the opposing directions (where the inner lanes are a metal grate) or a flat double-yellow line (where the inner lanes are paved). The speed limit is also reduced to {{convert|45|mph|abbr=on|round=5}} for cars and {{convert|20|mph|abbr=on|round=5}} for trucks.  The highway returns to Interstate standard for about 50 miles until it reaches the [[Sault Ste. Marie International Bridge]], which carries undivided lanes to the [[Canada–United States border|Canada–US border]] in the middle of the bridge, where I-75 terminates.
* The [[Thousand Islands Bridge]], which carries [[Interstate 81 in New York|I-81]] over part of the [[Saint Lawrence River]], is an undivided two-lane road.
* [[Interstate 93 in New Hampshire|I-93]] is a two-lane divided parkway, or a "[[super two]]", through [[Franconia Notch]] in [[New Hampshire]]. A four-lane Interstate Highway was once proposed here, but the concept was abandoned because of environmental concerns, in part because of vibrations that could harm the [[Old Man of the Mountain, New Hampshire|Old Man of the Mountain]] rock formation (which collapsed in 2003 regardless). This section of highway was for many years marked as [[U.S. Route 3 in New Hampshire|US&nbsp;3]] and "To I-93", but these have now been replaced with regular I-93 signs. The Federal Highway Act of 1973 exempts this {{convert|7.6|mi|km|adj=on}} stretch from the Interstate Highway standards that apply elsewhere, and this highway is considered to be I-93 for all practical purposes.<ref>{{cite web |first = Richard |last = Weingroff |url = https://www.fhwa.dot.gov/infrastructure/intrstat.cfm |title = Interstate System Conditions and Performance |work = Highway History |publisher = Federal Highway Administration |date = April 7, 2011 |access-date = August 20, 2012 }}</ref> This section of I-93 in New Hampshire is now the only remaining multi-mile section of two-lane freeway on an Interstate Highway in the United States.{{citation needed|date=June 2018}} In addition, parking along portions of I-93 through Franconia Notch was permitted until early 2019 when barriers and signage were posted due to safety concerns.<ref>{{Cite web |url = https://www.unionleader.com/nh/outdoors/hikers-warned-not-to-park-along-franconia-notch-parkway-in-multi-agency-crackdown/article_9cecd64f-77cf-5041-815d-9cd24b51fa56.html |title = Hikers warned not to park along Franconia Notch Parkway in multi-agency crackdown |first = John |last = Koziol |website = UnionLeader.com |date = May 23, 2019 |accessdate = April 15, 2021 }}</ref>
* Some stretches of Interstate highway use a [[barrier transfer machine]] on some bridges to convert inner lanes from one direction to the other, where it would be too costly to upgrade/rebuild to a higher-capacity bridge. In any case the traffic distribution is strongly asymmetric depending on the hour of the day. This kind of bridge typically contains undivided lanes without the flexible Jersey barrier that is manipulated by machines.

===Movable bridges===
[[File:Interstate 280 - New Jersey westbound approaching Stickel Bridge.jpg|thumb|right|I-280 westbound approaching the movable Stickel Bridge over the Passaic River in New Jersey|alt=A six lane freeway in an urban area with a vertical lift bridge in the distance. A green sign with flashing lights on the right side of the road reads Drawbridge ahead 700 feet.]]
By Interstate standard, all bridges on the Interstate system must be fixed as to not interrupt the flow of traffic.  Several bridges on the system, however, are movable:
* [[Interstate 5|I-5]] crosses the [[Columbia River]] from [[Portland, Oregon]], to [[Vancouver, Washington]], on the [[Interstate Bridge]], a vertical-lift bridge. The [[Columbia River Crossing]] project sought to replace this bridge<ref>{{cite web |author = Project staff |url = http://www.columbiarivercrossing.org/ |title = Home |work = Columbia River Crossing |publisher = [[Oregon Department of Transportation]] and [[Washington State Department of Transportation]] |access-date = August 28, 2009 }}</ref> until being abandoned in 2013.<ref>{{cite news |last = Read |first = Richard |title = Bridge Funds to Nowhere: Some of the $175 million in work for the now-defunct Columbia River Crossing might be useful someday, but much of it is just gone<!--print-edition headline--> |newspaper = [[The Oregonian]] |location = Portland |page = A1 |date = July 5, 2013 |url = http://www.oregonlive.com/business/index.ssf/2013/07/columbia_river_crossing_spends.html#incart_m-rpt-2 |access-date = July 5, 2013 }}</ref>  However, in 2019, a new project was approved, scheduled to begin work in 2025.<ref>{{Cite news |last = Theen |first = Andrew |date = September 24, 2019 |title = Oregon and Washington: We'll start building a new Interstate Bridge by 2025 |url = https://www.oregonlive.com/commuting/2019/09/oregon-and-washington-well-start-building-a-new-interstate-bridge-by-2025.html |work = The Oregonian |access-date = May 11, 2023 }}</ref> 
* [[Interstate 110 (Mississippi)|I-110]] has a drawbridge across the Back Bay of Biloxi in [[Biloxi, Mississippi]].
* [[Interstate 64 in Virginia|I-64]]—the [[Hampton Roads Beltway]]—crosses the [[South Branch Elizabeth River]] in [[Chesapeake, Virginia]], on the [[High Rise Bridge]], which is a drawbridge, expected to be replaced by a larger fixed bridge. It opened in July 2022.<ref>{{Cite news |url = https://www.13newsnow.com/article/news/local/mycity/chesapeake/groundbreaking-on-i-64-widening-high-rise-bridge-project/291-506860993 |title = Groundbreaking on I-64 widening, High Rise Bridge project |date = January 12, 2018 |access-date = December 31, 2019 }}</ref><ref>{{Cite news |url = https://www.pilotonline.com/inside-business/article_1f82c230-f81a-11e8-b84d-7b36d0f4f734.html |title = I-64 High-Rise Bridge project could raise economic opportunities |date = December 4, 2018 }}</ref><ref>{{Cite web |date = July 15, 2022 |title = Chesapeake's new High Rise Bridge opens Saturday |url = https://www.13newsnow.com/article/news/local/mycity/chesapeake/chesapeake-new-high-rise-bridge-ready-to-open-i-64/291-e3c65534-3fc5-474a-9ded-ecea39c56f1d |access-date = December 17, 2023 |website = 13newsnow.com |language = en-US }}</ref>
* [[Interstate 264 (Virginia)|I-264]] has a drawbridge, the [[Berkley Bridge (Virginia)|Berkley Bridge]], crossing the [[Elizabeth River (Virginia)|Elizabeth River]] in [[Norfolk, Virginia]].
* [[Interstate 278|I-278]] has a drawbridge across the [[Bronx River]] in [[New York City]].
* [[Interstate 280 (New Jersey)|I-280]] has a [[vertical-lift bridge]], the [[Stickel Memorial Bridge]], crossing over the [[Passaic River]] between [[Newark, New Jersey|Newark]] and [[Harrison, New Jersey]].
* [[Interstate 95 in the District of Columbia|I-95]]/[[Interstate 495 (Capital Beltway)|I-495]] pass together as the Capital Beltway over the [[Potomac River]] on the [[Woodrow Wilson Bridge]], a double-leaf bascule span. Even though the original bridge was replaced in the 2000s, the new bridge also has a draw span, albeit with more vertical clearance resulting in fewer openings than the old bridge—about 65 per year, an average of about one every six days.
* [[Interstate 695 (Maryland)|I-695]] has a drawbridge over [[Curtis Creek]], south of [[Baltimore]] and just west of the [[Francis Scott Key Bridge (Baltimore)|Francis Scott Key Bridge]]. This section of the Baltimore Beltway is not part of the Interstate Highway System, however, and is officially Maryland Route 695 despite the Interstate signage on the highway.<ref name="annearundelHLR">{{Maryland HLR |link= yes |year= 2007 |county1= Anne Arundel |accessdate= April 15, 2009}}</ref><ref>{{cite web |author = Highway Services Division |publisher = Maryland State Highway Administration |url = http://www.sha.maryland.gov/OBD/movablebridges.pdf |title = Movable Bridges on State Maintained Highways |access-date = October 18, 2010 |year = 2010 }}</ref>

===Freeway-to-freeway crosspaths without direct connection===
* [[Interstate 271|I-271]] in Ohio lacks a direct interchange with the [[Ohio Turnpike]] (I-80); traffic interchanges between the two via [[Interstate 77 in Ohio|I-77]] and [[Ohio State Route 8]], which both pass nearby.
* [[Interstate 475 (Ohio)|I-475]] has no direct interchange with the [[Ohio Turnpike]] ([[Interstate 80 in Ohio|I-80]]/[[Interstate 90 in Ohio|I-90]]) near [[Toledo, Ohio|Toledo]], though there is an indirect connection via [[U.S. Route 20 in Ohio|US 20]] and Dussel Drive.
* The Pennsylvania Turnpike Northeast Extension ([[Interstate 476|I-476]]) does not have a direct interchange with [[Interstate 78 in Pennsylvania|I-78]] in [[Allentown, Pennsylvania|Allentown]], though there is an indirect connection via [[U.S. Route 22 in Pennsylvania|US 22]] and [[PA 309]]. I-476 also has an indirect connection to [[Interstate 81 in Pennsylvania|I-81]] in [[Dupont, Pennsylvania|Dupont]] via a short stretch of [[Pennsylvania State Route 315|PA 315]], in addition to a direct connection at the turnpike's northern terminus in [[Clarks Summit, Pennsylvania|Clarks Summit]]. Additionally, while it connects directly to [[Interstate 80 in Pennsylvania|I-80]] near [[White Haven, Pennsylvania|White Haven]], the freeway-grade is disrupted when the ramps intersect [[Pennsylvania Route 940|PA 940]].
* [[Interstate 42]] connects to [[Interstate 95 in North Carolina|Interstate 95]] via [[U.S. Route 70 in North Carolina|U.S. Route 70]] in [[Selma, North Carolina]].
* [[Interstate 81 in Pennsylvania|I-81]] connects to the [[Pennsylvania Turnpike]] (I-76) via a {{convert|1.11|mi|km|adj=on}} stretch of [[U.S. Route 11|US 11]] in [[Carlisle, Pennsylvania]].
* The [[Massachusetts Turnpike]] ([[Interstate 90|I-90]]) passes over [[Interstate 391|I-391]] without interchange in [[Chicopee, Massachusetts]]. The overpass is about {{convert|1|mi|km|spell=in}} north of the I-391 southern terminus at [[Interstate 91|I-91]], and approximately {{convert|1.4|mi|km}} from the Mass Pike interchange with I-91 and [[U.S. Route 5|US 5]].
* [[Interstate 95 in New Jersey|I-95]] ([[New Jersey Turnpike#Route description#Extensions|NJ Turnpike Pearl Harbor Memorial Extension]]) passes under [[Interstate 295 (Delaware–Pennsylvania)|I-295]] without interchange in [[Columbus, New Jersey]]
* [[Interstate 195 (Maryland)|I-195]] passes over [[Interstate 895 (Maryland)|I-895]] without interchange near [[Halethorpe, Maryland]].
* [[Interstate 295 (Delaware–Pennsylvania)|I-295]] passes over the [[Pennsylvania Turnpike]] (I-276) without direct interchange in [[Bristol Township, Pennsylvania]], though an interchange is under construction that will provide direct connection.
* [[Interstate 99|I-99]] has connection gaps with the [[Pennsylvania Turnpike]] (I-70/I-76) and [[Interstate 80 in Pennsylvania|I-80]] in central Pennsylvania, both through at grade roads near [[Bedford, Pennsylvania|Bedford]] and [[Bellefonte, Pennsylvania]]. The latter is expected to become freeway-grade as part of I-99's aforementioned northern extension.

====Proposed====
* [[Birmingham Northern Beltline|I-422]] (proposed) would have no direct freeway connection to its parent [[Interstate 22|I-22]], though the two routes would cross near [[Adamsville, Alabama]].

==Connection gaps==
[[List of auxiliary Interstate Highways|Auxiliary Interstates]] (also known as three-digit Interstates) are intended to connect to their parent either directly or via a same-parented Interstate (like [[Interstate 280 (California)|I-280]] in California being connected to [[Interstate 80 in California|I-80]] via [[Interstate 680 (California)|I-680]]). Often, these connection gaps occur to eliminate concurrencies between other three-digit routes. Freeway gaps (signed or [[unsigned highway|unsigned]]) that officially connect auxiliary routes to the parent are excluded.

===Current examples===
<!--
*** list in numerical order by PARENT route number, please ***
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* [[Interstate 210 and State Route 210 (California)|I-210]] in California does not currently connect directly to [[Interstate 10 in California|I-10]] or any of its spurs according to freeway signage. It was signed all the way to I-10 until 1998, when [[California State Route 57]] replaced the portion of I-210 through [[Covina, California|Covina]] and [[San Dimas, California|San Dimas]] to provide a proper connection to current State Route 210. The former portion of I-210 now known as SR 57 still remains on the [[Interstate Highway System]] federally defined as Interstate 210<ref name="NHS">{{cite map |author = Federal Highway Administration |title = National Highway System: Los Angeles, CA |url = http://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/southern_california/losangeles_ca.pdf |archive-url = https://web.archive.org/web/20150518093019/http://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/southern_california/losangeles_ca.pdf |url-status = dead |archive-date = May 18, 2015 |scale = Scale not given |publisher = Federal Highway Administration |access-date = February 5, 2012 }}</ref> maintaining its connection to I-10, but it is not signed as per [[Caltrans]] tradition to sign state highways by their state definition over their federal definition. State Route 210, built as an extension to replace Route 30, connects to I-10 further east in [[Redlands, California|Redlands]], and California is petitioning to have that portion signed as I-210 as well. When that happens, this gap will close.{{cn|date=May 2023}}
* [[Interstate 238|I-238]] does not have a parent.  It was previously a part of [[California State Route 238]] that was built to Interstate standards, and it was added to the Interstate system using the same number it had as a state highway.  It was upgraded to be an auxiliary route of [[Interstate 80 in California|I-80]], but no three-digit combinations were available at the time the route was designated an interstate.  Additionally, the exit numbers continue the mileage from the state highway instead of starting over from 1.<ref>{{cite web |author = Cooper, Casey |url = http://gbcnet.com/roads/I-238/ |title = Indigestion 238 |publisher = Casey's Roads and Highways Page |access-date = January 26, 2013 }}{{unreliable source?|failed=y|date=December 2013}}</ref>
* Due to [[highway revolts]] in [[New York (state)|New York state]] forcing the interstate to terminate prematurely, none of the spurs of [[Interstate 78|I-78]] in New York City ([[Interstate 278|I-278]], [[Interstate 478|I-478]], [[Interstate 678|I-678]], [[Interstate 878|I-878]]) connect to the parent road I-78, nor is there any surface street with a state route designation with the same number that continues with a solid connection. I-78 was planned to extend southeast through New York City via the [[Lower Manhattan Expressway]], [[Williamsburg Bridge]] and [[Bushwick Expressway]], then east along what is now I-878 and north along what is now [[Interstate 295 (New York)|I-295]]. I-78 would have then split into two branches (the current I-295 and [[Interstate 695 (New York)|I-695]]), which would have both terminated at [[Interstate 95 in New York|I-95]].<ref>{{cite map |url = http://www.nycroads.com/history/1960_metro-1/ |publisher = [[Rand McNally and Company]] |title = New York City |year = 1960 |access-date = April 15, 2010 }}
* I-95 is shown on the [[Hutchinson River Parkway]] north of the [[Bruckner Interchange]], but the [[:File:New York, New York 1955 Yellow Book.jpg|1955 "Yellow Book" map]] shows the I-78 route on the [[Bruckner Expressway]].</ref><ref name="airport-reqs">{{Cite book |url = http://classify.oclc.org/classify2/ClassifyDemo?wi=2551801 |title = A Report on Airport Requirements and Sites in the Metropolitan New Jersey–New York Region |publisher = [[Port of New York Authority]] |year = 1961 |page = 73 |oclc = 2551801 }}</ref> I-478 comes the closest, and would have intersected I-78 as part of the [[Westway (New York)|Westway]] project;<ref>{{cite book |url = https://books.google.com/books?id=G4A2AQAAMAAJ |title = West Side Hwy Project, New York: Environmental Impact Statement |publisher = [[New York State Department of Transportation]]; [[Federal Highway Administration]] |year = 1977 |language = en |access-date = March 19, 2018 }}</ref>{{Rp|10}} this project was later canceled.<ref>{{Cite news |url = https://www.nytimes.com/1985/10/07/nyregion/the-legacy-of-westway-lessons-from-its-demise.html |title = The Legacy of Westway: Lessons from Its Demise |last = Roberts |first = Sam |date = October 7, 1985 |work = The New York Times |access-date = March 22, 2018 |language = en }}</ref> I-278, the only I-78 spur to leave New York City, was planned to extend northwest to I-78 at [[New Jersey Route 24|Route 24]].<ref>* {{cite map |publisher = New Jersey Department of Transportation |title = Union County Sheet 1 |year = 1967 |url = http://mapmaker.rutgers.edu/UNION_COUNTY/UnionCoHighway1967_1.gif |access-date = February 13, 2010 }}
* {{cite map |publisher = New Jersey Department of Transportation |title = Union County Sheet 2 |year = 1967 |url = http://mapmaker.rutgers.edu/UNION_COUNTY/UnionCoHighways1967_2.gif |access-date = February 13, 2010 }}</ref> Since all the spurs are interconnected, only one of them needs to be eventually connected to its parent route for all of them to conform to numbering standards.
* [[Interstate 585|I-585]] in South Carolina currently does not connect directly to [[Interstate 85 in South Carolina|I-85]]. Until 1995, I-85 was routed along present-day [[Interstate 85 Business (Spartanburg, South Carolina)|I-85 Business]]. In that year, I-85 was moved to the north to bypass Spartanburg while I-85 Business took over its former route, leaving I-585 without a connection to its parent route until upgrades to the existing [[U.S. Route 176|US 176]] highway are complete.<ref>{{cite web |url = http://info2.scdot.org//GISMapping/GISMapdl/Greenville_Spartanburg_Metro_2018.pdf |title = Greenville Spartanburg Metro 2018 |publisher = SCDOT |date = April 2021 |access-date = May 30, 2021 }}</ref>
* As of July 2022, [[Interstate 587 (North Carolina)|I-587]] in North Carolina does not connect with its parent route, [[Interstate 87 (North Carolina)|I-87]]. Upgrades to the existing [[U.S. Route 264|US 264]] freeway from [[U.S. Route 64 in North Carolina|US 64]] to [[Interstate 95 in North Carolina|I-95]] to Interstate standards, as well as extending I-87 via upgrades to US 64, will connect I-587 with its parent route.
* [[Interstate_335_(Oklahoma)|I-335]] in Oklahoma will not have a connection with its parent route, [[Interstate_35_in_Oklahoma|I-35]], until an extension of the road to [[Purcell,_Oklahoma|Purcell]] is built.
*At the present, [[Interstate 369 (Texas)|I-369]] in Texas does not connect to its parent route, [[Interstate 69 in Texas|I-69]].  I-369 is proposed to extend south via [[U.S. Route 59 in Texas|US 59]] to [[Tenaha, Texas|Tenaha]], where it will intersect with I-69 after its own extension via US 59 from [[Cleveland, Texas|Cleveland]], then via [[U.S. Route 84 in Texas|US 84]] from Tenaha to the [[Louisiana]] state line near [[Joaquin, Texas|Joaquin]].
* Numerous three-digit Interstate routes are unsigned on some portions, leading some to think there are connection gaps. These so-called connection gaps do not have internal unsigned concurrencies on other Interstate highway segments between the "parent route" and signed terminus.{{Examples|date=August 2024}}

==See also==
* {{portal-inline|U.S. Roads}}

==References==
{{Reflist}}

==External links==
* [http://www.roadfan.com/mtrfaq.html misc.transport.road FAQ]

{{interstates}}

{{DEFAULTSORT:List Of Gaps In Interstate Highways}}
[[Category:Interstate Highway System|Gaps]]
[[Category:Lists of roads in the United States|Interstate gaps]]
[[Category:Movable bridges on the Interstate Highway System| ]]