In February 1994, the American Society of Civil Engineers (ASCE) named the Dwight D.  Eisenhower System of Interstate and Defense Highways (the Interstate Highway System, or IHS) one of the “Seven Great Construction Wonders of America.” As the ASCE correctly observed, our interstate system is “the greatest public works project in history.”

The interstate system does not only link the nation, but it has significantly boosted economic productivity and helped to sustain a more than ten-fold increase in the GDP since construction of the system began in 1956. 

Interstate 10

Interstate 10 (I-10) is one of four transcontinental interstates (I-40, I-80 and I-90 are the others) in the IHS. It is also known as the Christopher Columbus Transcontinental Highway. This interstate highway serves as a major connector for cities, seaports, tourism, military and energy assets located along its path.

Interstate 10 serves the southern tier of the U.S. and runs east from the Pacific Coast Highway (State Route 1) in southern California to its junction with I-95 in Jacksonville, Florida. I-10 travels through eight states including (from west to east): California, Arizona, New Mexico, Texas, Louisiana, Mississippi, Alabama and Florida. It traverses  the desert Southwest, the widest part of Texas and several southeastern states. 

Trucks moving along I-10 in west Texas. (Photo: Texas DOT)

The total length of Interstate 10 is 2,460.34 miles. It is the fourth-longest of all the interstate highways. The length by state from west to east is:

California – 242.54
Arizona – 392.33
New Mexico – 164.27
Texas – 881.00
Louisiana – 274.42  
Mississippi – 77.19
Alabama – 66.31
Florida – 362.28

Major cities along I-10’s route include (from west to east) Los Angeles, Phoenix, Tucson, Las Cruces, El Paso, San Antonio, Houston, Baton Rouge, New Orleans, Gulfport, Mobile, Tallahassee and Jacksonville. About one-third of its length is within the state of Texas.

West I-10/US 70 and North US 99 at the San Bernardino Interchange. This was the temporary southern terminus of I-15 (later I-15E, I-215). Circa 1958. (Photo: AARoads, original attribute unknown)

The route

Within California, I-10 begins in Santa Monica, just east of the Pacific Ocean. The highway is heavily traveled in Los Angeles and it briefly joins Interstate 5. Interstate 10 leaves the greater Los Angeles metro area about 70 miles east of downtown Los Angeles. Just beyond the narrow San Gorgonio Pass I-10 enters the relatively rural desert. Desert cities along I-10 in California include Palm Springs, Indio and Blythe.

Phoenix, Arizona is the next major city along the route of I-10. It forms a freeway loop with I-17 through downtown Phoenix and then runs in a southeastern direction toward Tucson. It continues in a  southeastern direction, and then turns northeast toward Bowie.

Crossing the Peloncillo Mountains, I-10 enters New Mexico. This area is prone to high winds and dust storms. I-10 was built on the former routes of U.S. 70 and U.S. 80 east across open desert to Deming and Las Cruces.

This map shows the route of I-10 and some of the cities it runs through or near. (Map:

Entering Texas near the border with Mexico and the Rio Grande near El Paso, I-10 then crosses the vast expanse of west Texas. Because it runs through a rural area with extremely low traffic volumes, this stretch of the interstate is posted with an 80 mile per hour speed limit.

East of Van Horn, I-10 runs along the northern reaches of the Davis Mountains, and splits from I-20 in a rural area east of Fort Kent. Approaching San Antonio from the northwest, I-10 becomes a suburban freeway.

It then becomes a busy commuter route, and forms part of a loop encircling downtown San Antonio with I-35 to the west and U.S. 90 to the south. In addition, I-10 either follows the route or parallels U.S. 90 all the way to Houston. Nearing Houston, the freeway grows to 16 lanes along the Katy Freeway through Houston’s western suburbs. Continuing eastward, the highway leaves Texas at Orange.

Congested traffic in Houston. (Photo: CultureMap Houston)

When it enters southern Louisiana, I-10 passes areas of timberland, agricultural crops and bayous. The high connects the urban centers of Lake Charles, Lafayette and Baton Route. Because of the terrain, several major sections of I-10 are elevated in Louisiana, including the Acadian Thruway heading to Baton Rouge and along the edges of Lake Pontchartrain. I-10 and I-12 join and then they split; I-10 loops southward into New Orleans and I-12 is a bypass east into coastal Mississippi.

Interstates 10 and 12 reconnect at Slidell, just west of the Mississippi state line. I-10 crosses the Gulf Coast through the northern reaches of Gulfport, Biloxi and Moss Point, Mississippi. 

In Alabama, I-10 heads northeast toward Mobile. The interstate circumvents Mobile Bay through the George Wallace Tunnel in downtown Mobile and across the Mobile Bayway. The highway traverses rural areas again east of Loxley and enters Florida west of Pensacola. 

In Florida, I-10 travels through Pensacola before turning inland from Escambia Bay. The highway parallels the northern boundaries of Elgin Air Force Base, crosses the Apalachicola River, and runs eastward toward Tallahassee.

Interstate 10 traverses rural areas of northern Florida, then meets I-75 outside Lake City and crosses through the Osceola National Forest toward Jacksonville. In Jacksonville I-10 widens into a six- and eight-lane urban freeway, ending at I-95.


While parts of I-10 were built as far back as 1957, the last section of the highway to be completed was a section of the Papago Freeway from both I-17 interchanges in Phoenix, which did not open until 1990 (see main photo above).

Sections of the I-10 bridges over Lake Pontchartrain were destroyed by Hurricane Katrina. (Photo: Lousiana DOT)

While the majority of I-10 was completed in the 1970s, construction on it has really never ended. Widening projects in and near major cities along its route have occurred almost continuously, while major bridges have been rebuilt (such as the bridges across Lake Pontchartrain in southeastern Louisiana, which were severely damaged by Hurricane Katrina and the I-10 bridges across Escambia Bay in northwest Florida that were damaged by storm surge during Hurricane Ivan).

The I-10 bridges over Lake Pontchartrain. (Photo: Louisiana DOT)