List of gaps in Interstate Highways

For the most part, the United States Interstate Highway System is a connected system, with most roads completed. However, some Interstates have gaps. There are several cases covered here:

Related Topics:
United States - Interstate Highway System

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• True gaps, where two sections of road are intended to be part of the same Interstate, but the two sections are not physically connected, or are only connected by non-Interstates, or are connected but the connection is not signed as part of the highway
• Freeway gaps, where the Interstate is signed as a continuous route, but part or all of it is not up to freeway standards; this includes drawbridges, where traffic on the Interstate can be stopped by boats
• Connection gaps, where a three-digit Interstate does not connect to its two-digit parent via a freeway-standard connection

Not covered here are a few other cases worth mentioning:

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• Gaps in Interstate Highway standards, such as shoulder widths and bridge clearances, since these are too frequent
• Two-digit Interstate numbers which are meant to be repeated, one on each side of the country, namely I-76, I-84, I-86 and I-88
• Gaps on the Interstates in Alaska and Puerto Rico, since those are not held to the same standards
• Places where Interstates cross but don't connect via a freeway-standard connection
• Places where a three-digit Interstate connects to its parent via another three-digit Interstate of the same parent; the numbering system allows for this
• Sometimes, near toll booths (e.g. Mackinac Bridge toll booth), a brief segment of the Interstate will have a median break with a double-yellow line but have at least 4 lanes total (i.e. Super-4).
 
List of gaps in Interstate Highways: True gaps ►