Dwight D. Eisenhower National System of Interstate and Defense Highways | |
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Highway shields for Interstate 95 and Interstate 70, highways with true gaps and freeway gaps
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Interstate Highways in the 48 contiguous states
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System information | |
Formed: | June 29, 1956 |
Highway names | |
Interstates: | Interstate X (I-X) |
System links | |
There are gaps in the Interstate Highway system, where the roadway carrying an Interstate shield does not conform to the 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 things as at-grade crossings, traffic lights, undivided or narrow freeways, or movable bridges (lift bridges and drawbridges). This article deals with present-day gaps, as such examples were far more numerous during construction of the Interstate Highway System and the upgrading of existing roads to meet these standards, which did not occur everywhere at the same time. Temporary gaps, such as lane closures that reduce traffic to one lane and reduce speed limits, are also excluded.
True gaps are where two 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 two sections are either not physically connected at all, or they are connected but the connection is not signed as part of the highway. It should be noted that most of these gaps (except for the one on I-95) exist because the two segments are actually two unrelated highways that were built at different times, but assigned the same number; many times, the same number was assigned to the second segment with the intention of eventually connecting it to the first segment.
Freeway gaps occur 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 for vessels. This does not include facilities such as tollbooths, toll plazas, agricultural inspection stations, or border stations.