As of September 2007 , these signs have been replaced and use only the sequential exit number scheme. Exit numbers on I-295 have since been converted to mile -based numbers. The Federal Highway Administration (FHA) generally requires exit numbers (mile -based or sequential) on the Interstate Highway System; the FHA established that requirement in 1970.
The Manual of Uniform Traffic Control Devices (MUTED) encouraged use of mileposts and exit numbering by 1961. The FHA granted California an exception due to the cost of installing and maintaining additional signage.
Interstate 5, US 101, and then CA 11 (now I-110/CA 110) were numbered for short distances from downtown Los Angeles. Freeway connections were unnumbered, and junction numbers were only shown on plates, not on gore signs.
Originally, the initial completion date for this project was set as November 2004. However, the 2006 edition of the California MUTED removed any sort of compliance deadline for the exit numbers.
Nine states as of June 2008 , mostly in the Northeast, and the District of Columbia use sequential numbering schemes on at least one highway, although the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTED) requires these jurisdictions to transition to distance-based numbering. Although a ten-year compliance period was proposed for the new edition of the MUTED, a compliance date for this change was ultimately not adopted with the 2009 edition, meaning that the transition is accomplished through a systematic upgrading of existing signing and there is no specific date by which the change must be implemented.
Some of the states that currently have sequential numbering either have or intend to request a waiver from the Federal Highway Administration to retain their current numbering systems, while others have planned a gradual transition to mileage-based exit numbering over time as existing signage reaches the end of its serviceable life and is replaced. Older exit numbering schemes sometimes use cardinal directions (E, N, S, W; often E-W or N-S) depending on the directionally of the cross route(s), for example Interstate 93 in New Hampshire uses exits 15E and 15W for the cloverleaf interchange with U.S. Route 202 in Concord which is signed “east” and “west” at the interchange.
(As of 2019, New Hampshire is the only state to have never used distance-based exits, including “experimental” dual exit/ mile numbers/letters.) An example of sequentially-numbered exits in Connecticut on the Charter Oak Bridge, CT 15 / U.S. 5.
Work was to start in January 2016 to convert all highway exit numbers, though local opposition caused the state to halt immediate plans and re-evaluate the scheme. and the State Highway Administrator, Tom Violin is quoted in a Worcester Telegram & Gazette.
An interactive map showing existing and new exit numbers is located at http://newmassexits.com/. New Hampshire DOT has reportedly received permission to use Federal funding to convert to mileage-based, but has yet to announce a formal plan for conversion.
Rhode Island will complete its transition to mile -based exit numbers statewide by 2021. Governor Phil Scott reached an agreement with the Federal Highway Administration to use a dual sequential/ mile -based exit numbering system starting in 2020.
I-19 currently has all exit numbers and distances in kilometers, but speed limits in miles per hour. The road has received funding for the distances to be changed back to miles, but in response to local opposition against exit number changes, the Arizona Department of Transportation had decided to spend the money on other roads instead.
Similarly, the U.S. Route 54 freeway from El Paso to the New Mexico border also uses sequential exit numbering. Alaska : the Johansen Expressway three interchanges with sequential exit numbers.
Currently, I-49 from I-40 in Alma to Bentonville in northwest Arkansas follows the old numbering system off its old designation I-540. The exit numbers and mileage are derived from their distance from where the Fort Smith section of I-540 begins at the Oklahoma state line.
California uses exit numbers on all of its non- interstate highways statewide when they are built to freeway standards. Exit numbers on Routes 2A, 40, 184, 349, and unsigned SR 695 are mileage-based; these changes include the eastern end of the former Connecticut Turnpike.
The Wilbur Cross Parkway, eastbound, takes over the Merritt's sequential numbering. Toll roads under the Central Florida Expressway Authority also use distance-number exits.
The Lee Roy Salmon Expressway in Tampa uses a sequential-based exit numbering system. Exits on the controlled-access portion of New Circle Road (KY 4), which surrounds the urban core of Lexington, are numbered on the standard distance-based system.
Numbering increases in clockwise order, starting and finishing at the interchange with Nicholasville Road (US 27) near New Circle's southernmost point. All roads within the state's parkway system of former toll roads (some of which have been converted to Interstates, with others in the process of conversion) use the same distance-based numbering system used on interstates.
Maryland Route 32 has a peculiar distance-based exit set up in that the exits are numbered from east to west from Interstate 97 to Maryland Route 108 so that the eastern terminus of MD 32 starts at mile 0. The first exception was US 52's freeway portion through Rochester, which received mileage-based exit numbers in 2004 as part of a major widening project.
All other highways are mile -based, except for the Brigantine Connector in Atlantic City, which uses letters for exits. Other freeways (US-70 east of Las Cruces and NM 423 in Albuquerque) have no exit numbers due to their relatively short lengths.
In New York, most highways in the New York City metro region of this type use sequential numbering (an exception is the Belt Parkway system, which uses directional suffixes (N, S, E, W) and alphabetical suffixes.) Expressways and freeways without interstate designations upstate have unnumbered interchanges.
Some at-grade intersections (level junctions) have posted numbers; former examples are the Laconic State Parkway, NY 17, and within New York City, NY 27 along only the section of Linden Boulevard east of Kings Highway. Current examples are the Bronx River Parkway and, within New York City, NY 27 along Conduit Avenue only.
Interchanges in Westchester County were prefixed with W (e.g., W5), Putnam with P, Duchess with D, and Columbia with C. The Laconic Parkway received mile -based exit numbers in the summer of 2017 as part of an ongoing sign replacement project. In North Carolina, non- interstate freeways formerly did not use exit numbers.
Beginning in the 1990s, all interchanges on U.S. highways have been assigned exit numbers, either when they were constructed, or when the signage was updated. There is still an incomplete conversion, as some highways which have not been upgraded in many decades (such as portions of the U.S. 64 freeway in Nash County) lack exit numbers.
However, Ohio Department of Transportation Districts 2 and 6 have begun to employ exit numbers on non-Interstates using the south or west entrance into the state or highway beginning as the point of origin, and District 3 measures them from the south or west entrance into the respective county. In the 1990s, the Oregon Department of Transportation began numbering most sections of its freeways with mile -based exits, starting with US-26 and OR-217 west of Portland.
(These exits are based on internal limited-access road mileage; see State highways in Oregon for an explanation on these differences.) Pennsylvania's non- Interstate highways that have numbered exits are still numbered sequentially (such as the freeway portion of PA 28 between Pittsburgh and Kit tanning) except the toll roads that are part of the Pennsylvania Turnpike system.
The Leigh Valley Thruway (US 22) through Bethlehem and US 30 between York and Lancaster have no exit numbering, but do have mileposts that reflect the appropriate distance from the Ohio border. Tennessee generally does not post exit numbers on its non- Interstate freeways, except Nashville's partial beltway TN 155 (Briley Parkway).
Due to a major reconstruction project in the 1990s, which combined many exits, these jump from 8B to 20B. SH 130 uses mile -based exits starting at 497 and decreases to 411 at its northern terminus.
Exits on other freeways are based on a statewide reference system where the exit number is determined by the distance from either the northernmost (northwest corner of the Texas Panhandle, for north-south routes) or westernmost (Texas/New Mexico/Mexico tripping, near El Paso, for east-west routes) geographic reference point in Texas. Utah's higher-density freeways have exit numbers, including UT-154 (Angered Highway), UT-201, and UT-67 (Legacy Parkway).
Ten miles of US-89 in Davis County and US-40 / US-189 between I-80 and UT-32 are signed with exit numbers. Vermont does not use the mileage-based system on non-Interstates, although supplemental “Mile point Exit” placards indicating the mile -based exit number are being added to existing signage, with two exceptions: VT 127 and VT 289 in the Burlington area.
The numbers would have been continuous if the Christensen County Circumferential Highway were completed. The numbers start at Manhattan Drive just north of Burlington and end at Interstate 89 near Williston.
Freeway sections of US-4 and US-7 in the western part of the state use sequential numbering. Two exceptions are SR-14 from Vancouver to Camps (since the 1990s) and SR-16 from Tacoma to near Gig Harbor (since 2006, possibly to extend along all of SR-16 to its northern terminus in Worst), both milepost-based.
West Virginia has only one non- interstate with exit numbers, the US 22 freeway in Weirton. Originally, the initial completion date for installing exit numbers statewide was set for November 2004.
But because of California's budget concerns, exits (especially in the Greater Los Angeles and San Francisco Bay areas) have generally been numbered only when signs needed to be replaced. The state may eventually replace all older overhead signs (and thus add exit numbers) as part of an energy-saving measure: in 2014, Roads & Bridges reported that the California Department of Transportation was testing types of reflective sheeting to eliminate the need for electrical-sign lighting.
As of December 2020, Routes 9, 17 (Middletown section), 72, 82 and SR-571 are in the process of transitioning from sequential to mile -based numbering as part of ongoing sign replacement projects. Two short freeways whose exits were previously unnumbered, Route 184 and Route 349 in Proton received mileage-based exit numbers starting in 2018 as part of a sign replacement project that includes I-95 from New London to the Rhode Island state line (this section of I-95 will retain sequential exit numbers for the time being until signs along the entire length of I-95 are updated and ready for conversion).
As highways are converted to mile -based exit numbers, sequential numbers will be posted on “Old Exit XX” placards on advance guide signs and gore signs for at least two years following the conversion. Mile -based exit numbers on Interstate 4 in Volusia County, Florida circa 2003.
From the 1990s through the 2010s, Illinois gradually added exit numbers to its remaining toll interstates. Exits on I-69 between Indianapolis and the Michigan state line underwent a second renumbering in 2012, when the first portion of the I-69 extension to Evansville opened that year.
Massachusetts had planned to start transition from sequential to mile -based exit numbers in 2016, but was halted due to local opposition from residents of Cape Cod. Mass DOT sought an exemption for the Mid-Cape Highway from the renumbering requirement due to local concerns, which was denied by the FHA.
The state has no timeline for converting its remaining highways to mileage-based numbering, although it appears that NOT and NY STA will gradually transition to mile -based exit numbers through sign replacement projects, as evidenced by a sign replacement and exit numbering contract for the Laconic State Parkway completed in 2017, and a similar contract to replace signs and renumber exits on I-84 starting in late 2018. On routes where exit numbers are converted, “Old Exit XX” placards will be placed alongside advanced guide signs for a period of time for motorists to adjust to the new numbering system.
A third contract has been awarded to add mile -based exit numbers to Routes 4, 78, and 403 starting in the middle of 2019. As of January 2021, I-95 is the only highway remaining in the state that uses sequential numbering.
The route originally curved around the west of Ne phi, but was changed to the east. The original surveyor measurements did not reflect this change, and DOT corrected this error after GPS systems began to give wrong mileage directions.
Vermont reached an agreement with the Federal highway Administration in 2019 to use dual sequential/ mile -based exit numbers. The agreement stipulates that Vermont must convert to mile -based exit numbers during the next round of sign replacements, planned for some point in the 2030s.
Virginia did not post temporary placards indicating the former exit numbers after the conversion. The Pennsylvania Turnpike had sequential numbers when its first section opened on October 1, 1940, eventually using Exits 1 to 30 for the mainline from Ohio to New Jersey.
In the early 1950s, New Jersey's Garden State Parkway opened, probably the first road to use distance-based exit numbers. The Gulf Freeway (US 75, later Interstate 45) in Houston, Texas had sequential numbers by 1956.
The numbering scheme started at the freeway's northern end in downtown Houston, and counted up towards the southeast and Galveston. Massachusetts started handing out exit numbers in the 1950s to its freeways in and around the Boston area, with an uncommon system of making sure every freeway's intersection with Route 128 was an “Exit 25”, numbers increasing away from Boston.
^ Laconic State Parkway to get exit numbers, The Journal News, Sep 4, 2016 ^ a b Patch, David (February 10, 2007). “Cal trans tests reflective sheeting for guide-sign visibility and cost savings”.