Exit 0

There are several places with a highway interchange labeled as Exit 0 (zero). In some U.S. states (including Massachusetts), this is the point where a highway begins, usually at another highway. Motorists driving on such a road must exit onto the other highway in one direction or the other. While this occurs everywhere, only some places officially designate this as an exit numbered "0". A few exits (or visitor centers) are right at a state line, and if the state uses a mile-log system, then the numbering system itself requires that the exit number be zero, though some states renumber the exit as "Exit 1". An example of this is the exit on Interstate 44 for Baxter Springs, Kansas, which is less than one-half mile from Oklahoma, but is signed as Exit 1.

Explanation

The distinction is between "ordinal numbers" (first, second, third, ...), which are used for "order", and "cardinal numbers" (0, 1, 2, 3, ...), which are used for "quantity". Some states number their exits using ordinal numbers, beginning with 1 (meaning first), but other states using cardinal numbers that measure distance from a starting point. In the latter case, the starting point is labelled zero, because the exit occurs at a distance of zero from the starting point of the highway.

Exit numbers that measure distance are cardinal numbers, while exit numbers that identify a position in a sequence are ordinal numbers. Similar distinctions occur in numbering the floors of a building, and in numbering the years in history. See Floor numbering and Year zero.

Occurrences

At state lines

*Interstate 10 in western Texas, at the border with New Mexico (see Anthony, Texas and Anthony, New Mexico)
*Interstate 40 in western Texas, at the border with New Mexico (see Glenrio, Texas/New Mexico)
*Interstate 65 in Jeffersonville, Indiana, immediately after the John F. Kennedy Memorial Bridge crosses the Ohio River from Louisville, Kentucky
*Interstate 70 in northern West Virginia, at the border with Ohio (in Wheeling, West Virginia on Wheeling Island)
*Interstate 90 in western Montana, at the border with Idaho
*Interstate 90 in northwestern Indiana, at the border with Illinois (in Hammond, Indiana approaching the Chicago Skyway)

At other highways

*Colorado at US-36 and Interstate 25 North. The exit is at the western terminus of I-270 in the Denver metro area.
*Massachusetts
*New Brunswick
*New Jersey the beginning/end of the Garden State Parkway, approaching Cape May.
*Terminus of the Trans-Canada Highway in Horseshoe Bay, West Vancouver, British Columbia
*Halifax Bicentennial Drive terminates at Bayers Road and the final exit to Joseph Howe Drive is listed as Exit 0.
*In Indiana near Louisville, KY, the western terminus of I-265 is labeled as Exit 0 at the ramps for I-64.
*Also in Indiana at the junction of I-469 and I-69 south of Fort Wayne. The final exit of I-469 splits into Exits 0A and 0B.
*Pennsylvania at the junction of Pennsylvania Route 66 and U.S. Route 119. This exit is divided into exits 0A and 0B.
*In Iowa near Iowa City, the southern terminus of I-380 ends with Exits 0A and 0B at the junction of I-80 and US 218/IA 27.
*In Illinois the southern terminus of I-155 near Lincoln is designated as Exit 0, and it splits into Exits 0A and 0B.

External resources

* [http://www.theslowlane.com/98tripd/exit0.html Photo of I-90 Exit 0 at the Idaho / Montana border]
* [http://illi-indi.com/Gallery.php?id=2789&section=30901&terminus=Western+Terminus Photo of I-90 Exit 0 at the Indiana / Illinois border]
* [http://modena.intergate.ca/personal/pl8s/TCH/1E_4B.jpgPhoto of Trans-Canada Exit 0 at Horseshoe Bay, British Columbia]
* [http://www.aaroadtrips.com/i-070b_wv.html Photos of Exit 0 signs along Interstate 70 in West Virginia]
* [http://www.interstate-guide.com/i-155_il.html Photos of road signs along interstates near Lincoln, IL]
* [http://www.teresco.org/pics/signs/20031108/exit0.jpgPhoto of I-10 Exit 0 in western Texas]
* [http://www.okroads.com/dandm/i40tx.html Page containing photo of I-40 in western Texas]