Interstate 10


Interstate 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, 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 in Santa Monica, California, to I-95 in Jacksonville, Florida. Other major cities connected by I-10 include Los Angeles, Phoenix, Tucson, 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

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, and ending at I-110/SR 110. The segment between the East Los Angeles Interchange, in East Los Angeles, and the city of San Bernardino, 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 U.S. 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, 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 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, 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, west of Willcox, at the milemarker 320 exit for the rest stop. The westbound lanes of I-10 briefly cross above above sea level.

New Mexico

In New Mexico, I-10 more or less follows the former path of US Route 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 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. north of Deming on US 180 is State Road 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, 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 to State Highway 20 in west El Paso, I-10 is bordered by frontage roads South Desert for lanes along I-10 east and North Desert for lanes along I-10 west. The Interstate then has no frontage roads for 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 '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 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 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 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 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 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 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.