Exit number

In some countries, such as the United States and Canada,[1] it is also marked on a sign in the gore.

Exit numbers typically reset at political borders such as state lines.

A milder version of this has been recently used on the West Side Highway, also in New York, where only the major intersections are numbered (possibly to match the planned exits on the cancelled Westway freeway).

As a means of educating motorists, some state highway maps include a brief explanation of the exit numbering system on an inset.

There are also occurrences of this happening on the New Jersey Turnpike; the original interchanges opened in 1951, with newer exits as recently as 1982.

For instance, the Hutchinson River Parkway in New York was renumbered so that its northernmost exit, 27, became 30.

However, the Merritt Parkway, which continued the Hutchinson's exit numbers in Connecticut, was not renumbered.

As more highways were built, states and countries began to experiment with distance-based (mile-based or kilometer-based) exit numbers.

The first mile-based system known was implemented on the Garden State Parkway in New Jersey in the late 1950s.

Distance based numbering is the norm for most highways in the United States and Canada.

Examples of highways with an exit 0 are British Columbia Highway 1 on the mainland, Interstate 70 in Wheeling, West Virginia, along the West Virginia–Ohio border, and Interstate 90 on the Montana side of the Idaho–Montana border.

One reason for starting with a number higher than 1 is that the maintaining agency expects that the highway will be extended.

Distance-based exit numbering is used in Queensland, although there is not a consistent approach for defining the datum.

Victoria and New South Wales have partially implemented sequential exit numbering on selected urban motorways.

For instance, the M31 Hume Motorway in New South Wales has exit numbering between Prestons and Campbelltown.

At one time, it referred to junctions on the Autostrada del Sole[4] by number, and published same on toll tickets; though these may not have been posted on signs.

In the United Kingdom they are frequently referenced in the media as the number with "J" on front of it, with for example Junction 58 being referred to as "J58"; as such this abbreviated term has entered popular usage.

In the Republic of Ireland, junction numbers have existed since the opening of the first section of the M50 motorway in 1990.

Instead of replacing existing ramp and link signs, the exit numbers were added as supplementary information.

However, the exit signs now not only indicate the distance number, but they also display the Chinese code-name for the interchange.

Exit numbers on Interstate 4 in Volusia County, Florida . In this case, mile-based exits 111A and 111B had been sequential exits 53CA and 53CB, as the 'OLD 53CA' tab shows.
On a road with distance-based exit numbering, the exit number (shown here on a gore sign) matches a nearby mile or kilometer marker.
Puerto Rico is the only place in the United States that uses Spanish like the "Salida 5B" sign.
The New Jersey Turnpike at exit 8. This interchange was opened in 1951.
The New Jersey Turnpike at exit 8A several miles north of exit 8. This interchange was opened in the 1970s, which is why the suffix exists.
Exit 40 along the Capital Beltway (I-495) circling Washington, D.C., which is located at milepost 40
An exit sign (kilometer-based) on Quebec Autoroute 640 in Quebec
Exit numbers in most countries in Continental Europe
Exit 10 at the intersection of the highway 20 on the highway 4 ( E8 / E75 ) in Oulu, Finland
A UK motorway sign showing a junction number (25)
An exit number on a Québec Autoroute
Exit gore sign in the Philippines