# Interstate 10

Interstate 10 (I-10) is the southernmost transcontinental highway in the Interstate Highway System of the United States. It is the fourth-longest Interstate in the country at 2,460.34 miles (3,959.53 km), following I-90, I-80, and I-40. It was part of the originally planned Interstate Highway network that was laid out in 1956, and its last section was completed in 1990.
I-10 stretches from the Pacific Ocean at State Route 1 (SR 1, Pacific Coast Highway) in Santa Monica, California, to I-95 in Jacksonville, Florida. Other major cities connected by I-10 include (from west to east) Los Angeles, Phoenix, Las Cruces, El Paso, San Antonio, Houston, Baton Rouge, New Orleans, Gulfport, Mobile, Pensacola, and Tallahassee. Over one-third of its total length is within the state of Texas, where the freeway spans the state at its widest breadth.

## Route description

Lengths :
| | mi | km |
| CA | 242.54 | 390.33 |
| AZ | 392.33 | 631.39 |
| NM | 164.27 | 264.37 |
| TX | 881.00 | 1,417.83 |
| LA | 274.42 | 441.64 |
| MS | 77.19 | 124.23 |
| AL | 66.31 | 106.72 |
| FL | 362.28 | 583.03 |
| Total | 2,460.34 | 3,959.53 |

### California

Between its west terminus in Santa Monica, California, and the major East Los Angeles Interchange, I-10 is known as the Santa Monica Freeway. The Santa Monica Freeway is also called the Rosa Parks Freeway, named after the civil rights activist, for the segment beginning at I-405 (San Diego Freeway), and ending at I-110/SR 110 (Harbor Freeway). The segment between the East Los Angeles Interchange, in East Los Angeles, and the city of San Bernardino, 63 miles (101 km) long, is called the San Bernardino Freeway.
Other names exist for I-10. For example, from 1976 to 2022, a sign near the western terminus of the highway in Santa Monica proclaimed the highway to be the Christopher Columbus Transcontinental Highway. The state legislature authorized its removal in 2022 after years of lobbying by Native Americans.
I-10 is known to a considerably lesser degree as the Veterans Memorial Highway, and it is listed as a Blue Star Memorial Highway. In Palm Springs, I-10 is also named the Sonny Bono Memorial Freeway, named after the singer, actor, and politician, as a tribute to the late entertainer who served both as the mayor of Palm Springs, and as a US Representative. Another stretch a short distance east in Indio is proclaimed the Doctor June McCarroll Memorial Freeway, named after the nurse known for popularizing road lane striping.

### Arizona

In Arizona, the highway is designated the Pearl Harbor Memorial Highway. The portion through Phoenix is named the Papago Freeway, and it is a vital piece of the metropolitan Phoenix freeway system. This designation starts at State Route 101 (SR 101; Loop 101), near 99th Avenue, and continues eastward to the interchange southeast of downtown, which is the terminus of I-17.
Near Buckeye, the freeway has milemarkers posted every 0.2 miles (0.32 km) from 112.2 to 110.8 with the Interstate shield and direction of travel posted on the westbound lanes. On the eastbound lanes, milemarkers from 110.8 to 112.2 do not include the I‑10 shield and direction of travel.
From the southern terminus of I-17 to the southernmost junction with SR 202 (Loop 202), the highway is signed as the Maricopa Freeway. This name holds true as well for I-17 from its southern terminus to the Durango Curve south of Buckeye Road. From Loop 202 south to the eastern terminus of I-8 just southeast of Casa Grande, the highway is declared the Pearl Harbor Memorial Highway. The Arizona Department of Transportation also has maps that show it as the Maricopa Freeway, while the American Automobile Association and other sources show it as the Pima Freeway. The latter's name is used on a stretch of Loop 101 from Loop 202 to I-17.
Between I-17 in Phoenix and the I-19 interchanges in Tucson, I-10 is included in the federally designated CANAMEX Corridor, extending from Mexico City, Mexico, to Edmonton, Alberta.
In Tucson, between I-10 mileposts 259 and 260 are interchange ramps connecting I-10 with the northern terminus of I-19.
The highest elevation along I-10 occurs just east of Tucson, 20 miles (32 km) west of Willcox, at the milemarker 320 exit for the rest stop. The westbound lanes of I-10 briefly cross above 5,000 feet (1,500 m) above sea level.

### New Mexico

In New Mexico, I-10 more or less follows the former path of US Route 80 (US 80) across the state, although major portions of old US 80 were bypassed in the western New Mexico Bootheel and in Doña Ana County. I-10 passes through three southern New Mexico municipalities of regional significance before the junction with I-25: Lordsburg, Deming, and Las Cruces. Most of I-10 in New Mexico, between exit 24 and exit 135, is concurrent with US 70.
At Lordsburg is the western junction of US 70 and a concurrency; the two highways are joined all the way to Las Cruces. Several exits between Lordsburg and Deming are either for former towns (including Separ, Quincy, and Gage) or lack any town at all.
At Deming is the western junction of US 180, which also forms a concurrency with I-10 all the way to El Paso. One mile (1.6 km) north of Deming on US 180 is State Road 26 (NM 26) which serves as a short cut to north I-25 and Albuquerque.
I-10/US 70/US 180 continue east to Las Cruces which is the southern end of I-25. US 70 leaves I-10 (prior to the junction with I-25), heading northeast to Alamogordo and passing through the north side of Las Cruces. The junction with I-25 occurs just south of the New Mexico State University campus, on the southern end of Las Cruces. I-10/US 180 becomes concurrent with US 85 at the junction with I-25. I-10/US 85/US 180 then turns south to the Texas state line, crossing it at Anthony.

### Texas

From the state line with New Mexico (at Anthony) to State Highway 20 (SH 20) in west El Paso, I-10 is bordered by frontage roads South Desert for lanes along I-10 east (actually headed south) and North Desert for lanes along I-10 west (headed north). The Interstate then has no frontage roads for nine miles (14 km) but regains them east of downtown and retains them to Clint. In this stretch, the frontage roads are Gateway East for the eastbound lanes and Gateway West for the westbound lanes. All four frontage roads are one-way streets. Gateway East and Gateway West are notable, in particular, for the Texas Department of Transportation (TxDOT)'s liberal usage of the Texas U-turn at most underpasses of I-10 on this stretch.
I-10 is the western terminus for I-20, and the two highways intersect in Reeves County, about 41 miles (66 km) southwest of Pecos, at milemarker 186.
A small portion of I-10 from Loop 1604 to Downtown San Antonio is known as the Northwest Expressway or the McDermott Freeway, while another portion from downtown to Loop 1604 east is called East Expressway or José López Freeway. In Downtown San Antonio, it has a concurrency with I-35, and, throughout most of the northwest side of the city, it has a concurrency with US 87, which begins in Comfort, before turning off and heading east out of the city. Starting in San Antonio, it follows a more direct route of US 90, with occasional small concurrences.
In Houston, from the western suburb of Katy to downtown, I-10 is commonly known as the Katy Freeway. This section has as many as 18 lanes (12 main lanes and 6 mid-freeway high-occupancy toll [HOT]/high-occupancy vehicle [HOV] lanes, not counting access road turning lanes) and is one of the widest freeways in the world. The space for the expansion was the right-of-way of the old Missouri–Kansas–Texas Railroad. The section east of Downtown Houston is officially known as the East Freeway, although it is widely known by locals as the Baytown East Freeway due to a marketing push by Baytown, one of the largest cities in Greater Houston.
In Beaumont, it is known as I-10 south, south of Calder Avenue, and I-10 north, north of Calder Avenue. It is known as I-10 east from the I-10 curve to the Neches River, which is Beaumont's and Jefferson County's eastern boundary line. Continuing into Orange County and passing through the city of Orange at the easternmost end of Texas, and located at the base of the Sabine River bridge is the last I-10 milemarker in Texas, number 880, before entering into Louisiana. Approximately 36 percent of I-10's entire route is located within Texas; the longest segment of any signed Interstate within one state.

### Louisiana

In Lake Charles, a 13-mile (21 km) loop route signed as I-210 branches off of I-10 and goes through the southern portion of the city. In Lafayette, it serves as the southern terminus for I-49. Shortly afterward, there is an 18-mile (29 km) stretch of elevated highway between Lafayette and Baton Rouge known as the Atchafalaya Swamp Freeway, as it goes over the Atchafalaya River, across the Atchafalaya Basin Bridge, and the adjacent swamps. It crosses the Mississippi River at the Horace Wilkinson Bridge in Baton Rouge, where the eastbound lanes are the only portion of I-10 that is essentially one lane. After crossing the Horace Wilkinson Bridge, two lanes from I-110 south merge with two lanes I-10 east into three lanes with one of the eastbound lanes quickly becoming an exit only lane. After this, the highway is back to four lanes approaching the I-10/I-12 split. I-12 links Baton Rouge to Slidell and bypasses I-10's southward jog through New Orleans by remaining north of Lake Pontchartrain. On this route, I-10 serves as the southern terminus for I-55 in LaPlace and crosses over a portion of Lake Pontchartrain on the I-10 Bonnet Carré Spillway Bridge. In New Orleans, a stretch of I-10 from the I-10/I-610 Junction near the Orleans–Jefferson parish line to the US 90/US 90 Business (US 90 Bus.) junction is known as the Pontchartrain Expressway. A dip near the I-10/I-610 junction to travel under a railroad track is one of the lowest points in New Orleans and is highly susceptible to flooding. Buildups of rainwater dozens of feet deep (several meters) are commonplace during hurricanes. Near Slidell, I-10 serves as the eastern terminus of I-12 and the southern terminus of I-59; turning east to the Mississippi state line. The highway is known as the Stephen Ambrose Memorial Highway, named after the historian and writer, until the state line.
I-310 and I-510 are the built sections of what was slated to be I-410, which would have acted as a southern bypass of New Orleans. They function as spur routes serving lower density or suburban areas west and east of New Orleans respectively. I-610 is a shortcut from the eastern to western portion of New Orleans avoiding I-10's detour into the New Orleans Central Business District.

### Mississippi

I-10 in Mississippi runs from the Louisiana state line to the Alabama state line through Hancock, Harrison, and Jackson counties on the Gulf Coast. It passes through the northern sections of Gulfport and Biloxi while passing just north of Pascagoula and Bay St. Louis. It also passes right south of the NASA Stennis Space Center. The highway roughly parallels US 90.
The law defining the route of I-10 is Mississippi Code § 65-3-3.

### Alabama

I-10 crosses over the border from Jackson County, Mississippi, and it goes through Mobile County in southwestern Alabama. In Mobile, I-10 is the southern terminus of I-65. In downtown Mobile, I-10 goes through one of the few highway tunnels in Alabama, the George Wallace Tunnel under the Mobile River.
The speed limit of the eastbound approach is posted at 40 mph (64 km/h) because of the sharp downward curve approaching the tunnel. The highway then crosses approximately eight miles (13 km) of the upper part of Mobile Bay on the Jubilee Parkway, a bridge that local people call the "Bayway". The highway is next to Battleship Parkway. On the other side of Mobile Bay, the highway goes through the suburban area of Baldwin County before passing through Malbis, Loxley, and then on to the Perdido River to cross over into Florida.

### Florida

I-10 travels north of the cities of Pensacola and Tallahassee, serving the suburban areas within each respective city. In the former, a six-mile (9.7 km) spur route serves the downtown area, signed as I-110. Most of I-10 in Florida travels through some of the least-populated areas in the state, with large portions of I-10 west of I-295 in Jacksonville having only four lanes.
In Jacksonville, as in Arizona, I-10 is designated as the Pearl Harbor Memorial Highway. The route officially ends at the I-10/I-95 interchange northwest of Downtown Jacksonville. Throughout much of Florida, I-10 is also State Road 8 (SR 8), though it is not signed as such. (I-110 in Pensacola being known as SR 8A.)

## History

While the highway has existed as far back as 1957, the last section of the entire route to be completed was a section of the Papago Freeway from both I-17 interchanges (including the Deck Park Tunnel) in Phoenix, which opened in 1990.
Many widening projects have taken place on the interstate in the late 2000s. In Pensacola, Florida, a three-mile (4.8 km) stretch of I-10 was widened to six lanes in 2008. In Tallahassee, Florida, construction was completed in June 2009 on a project to widen a roughly eight-mile (13 km) stretch of I-10 to six lanes (eight in some places). In Tucson, Arizona, all exits between Prince Road and 22nd Street reopened after an extensive, three-year improvement project. I-10 was widened from six to eight lanes, and seven bridges and underpasses have been built to deal with congestion. I-10 from the I-8 interchange in Casa Grande to Marana was widened from four to six lanes from the second half of 2007, to its completion in 2009. Also in Arizona, from Verrado Way in Verrado, Buckeye, all the way to Avondale, the Interstate was widened throughout the late 2000s and early 2010s, with an HOV lane added between Estrella Parkway in Goodyear and Loop 101.
Texas formerly shared the highest speed limit in the nation with Utah's test section of I-15. The speed limit along I-10 from Kerr County to El Paso County was raised by the Texas Legislature to 75 mph (121 km/h) in 1999 and to 80 mph (130 km/h) in 2006. However, the nighttime maximum speed limit remained 65 mph (105 km/h), and the daytime truck speed limit was 70 mph (110 km/h). With 70,000 miles (110,000 km) of highway in Texas, the 432-mile (695 km) stretch of I-10, and 89 miles (143 km) of I-20, between Monahans and the I-10 interchange at the cusp of the Davis Mountains, only a small percentage of roads were affected. On September 1, 2011, nighttime speed limits were eliminated, and the statutory maximum speed limit in Texas was increased from 75 to 80 mph (121 to 129 km/h).
As far back as the 1990s, Florida and Alabama have considered a connector that would link Dothan, Alabama, with I-10. In 2008, a proposal to make this new highway a toll road and to expedite its construction to complete it in five years surfaced. In 2012, federal funds previously set aside for the connector were allocated to other projects. In 2014, Florida sought bids for a feasibility study.

## Junction list
### California

    SR 1 in Santa Monica
    I-405 on the Mar Vista–Palms–West Los Angeles neighborhood line
    I-110 in Downtown Los Angeles
    I-5 in Boyle Heights; the highways travel concurrently through Boyle Heights.
    SR 60 in Boyle Heights
    US 101 in Boyle Heights
    I-710 on the Monterey Park–Alhambra city line
    I-605 in Baldwin Park
    SR 57 / SR 71 on the Pomona–San Dimas city line
    I-15 in Ontario
    I-215 in Colton
    Future I-210 / SR 210 in Redlands
    SR 60 in Beaumont
    SR 79 in Beaumont
    SR 111 near Palm Springs
    SR 62 in Whitewater
    SR 86 near Indio
    SR 177 in Desert Center
    US 95 in Blythe; the highways travel concurrently to Quartzsite, Arizona.

### Arizona

    US 95 / SR 95 in Quartzsite
    US 60 southwest of Brenda
    SR 85 in Buckeye
    SR 303 in Goodyear
    SR 101 on the Avondale–Tolleson city line
    SR 202 in Phoenix
    I-17 / US 60 in Phoenix
    SR 202 / SR 51 in Phoenix
    I-17 / US 60 in Phoenix
    SR 143 in Phoenix
    US 60 in Phoenix
    SR 202 on the Phoenix–Chandler city line
    I-8 in Casa Grande
    I-19 in Tucson
    US 191 north-northwest of Cochise; the highways travel concurrently to northeast of Willcox.

### New Mexico

    NM 80 south-southwest of Lordsburg
    NM 338 southwest of Lordsburg
    NM 146 north of Hachita
    NM 28 in Las Cruces
    US 70 in Lordsburg; the highways travel concurrently to Las Cruces.
    US 180 in Deming; the highways travel concurrently to El Paso, Texas.
    I-25 / US 85 on the Las Cruces–University Park line. I-10/US 85 travels concurrently to El Paso, Texas

### Texas

    I-110 / US 54 in El Paso
    US 62 / US 180 in El Paso
    US 90 in Van Horn
    I-20 in Reeves County
    US 67 west of Fort Stockton; the highways travel concurrently to east-southeast of Fort Stockton.
    US 285 in Fort Stockton
    US 385 in Fort Stockton; the highways travel concurrently to east-southeast of Fort Stockton.
    US 190 west-southwest of Iraan
    US 277 in Sonora
    US 83 / US 377 in Junction. I-10/US 83 travels concurrently to north of Segovia.
    US 290 northwest of Mountain Home
    US 87 in Comfort; the highways travel concurrently through San Antonio.
    I-410 in San Antonio
    I-35 in San Antonio; the highways travel concurrently through Downtown San Antonio.
    I-35 / US 90 in San Antonio. I-10/US 90 travels concurrently to west-southwest of Seguin.
    I-37 / US 281 in San Antonio
    I-410 / SH 130 in San Antonio; I-10/SH 130 travel concurrently until east of Seguin.
    US 90 in Seguin
    US 183 in Luling
    US 90 east of Waelder
    US 77 in Schulenburg
    US 90 east-northeast of Schulenburg
    US 90 west-southwest of Glidden
    US 90 east of Columbus; the highways travel concurrently to Sealy.
    US 90 in Sealy; the highways travel concurrently to west-southwest of Brookshire.
    US 90 in Katy; the highways travel concurrently through Houston.
    I-610 in Houston
    I-45 in Houston
    I-69 / US 59 in Houston
    I-610 / US 90 in Houston
    US 69 / US 96 / US 287 in Beaumont; the highways travel concurrently through Beaumont.
    US 90 in Beaumont
    US 90 in Beaumont; the highways travel concurrently to Toomey, Louisiana.

### Louisiana

    I-210 east of Sulphur
    US 90 west-southwest of Westlake; the highways travel concurrently through Lake Charles.
    US 171 in Lake Charles
    I-210 east-northeast of Lake Charles
    US 165 east-northeast of Iowa
    I-49 / US 167 in Lafayette
    I-110 in Baton Rouge
    I-12 in Baton Rouge
    US 61 southeast of Sorrento
    US 51 in LaPlace
    I-55 in LaPlace
    I-310 west of Kenner
    I-610 in New Orleans
    US 61 in New Orleans
    US 90 in New Orleans
    I-610 in New Orleans
    US 90 in New Orleans
    I-510 in New Orleans
    US 11 in New Orleans
    US 190 in Slidell
    I-12 / I-59 in Slidell

### Mississippi

    US 49 in Gulfport
    I-110 in D'Iberville

### Alabama

    US 90 on the Theodore–Tillmans Corner line.
    I-65 in Mobile
    US 90 / US 98 in Mobile
    US 90 / US 98 east of Mobile
    US 90 / US 98 in Daphne

### Florida

    US 29 on the Brent–Ensley CDP line
    I-110 on the Brent–Ensley–Ferry Pass CDP line
    US 90 in Ferry Pass
    US 331 in DeFuniak Springs
    US 231 south of Cottondale
    US 90 in Midway
    US 27 in Tallahassee
    US 319 in Tallahassee
    US 90 in Tallahassee
    US 19 north-northeast of Capps
    US 221 south-southeast of Greenville
    US 90 southeast of Falmouth
    US 129 north-northeast of Live Oak
    I-75 south of White Springs
    US 41 northwest of Five Points
    US 441 in Lake City
    US 90 southwest of Sanderson
    US 301 south-southwest of Baldwin
    I-295 in Jacksonville
    US 17 in Jacksonville; the highways travel concurrently through Jacksonville
    I-95 / US 17 in Jacksonville

## Auxiliary routes

* Los Angeles, California: I-110, I-210, I-710
* San Bernardino, California: I-210
* El Paso, Texas: I-110
* San Antonio, Texas: I-410
* Houston, Texas: I-610
* Lake Charles, Louisiana: I-210
* Baton Rouge, Louisiana: I-110
* New Orleans, Louisiana: I-310, I-510, I-610, I-910 (Unsigned)
* Biloxi, Mississippi: I-110
* Pensacola, Florida: I-110
* Business routes of Interstate 10
Another I-310 is proposed to connect to Gulfport, Mississippi as well.