Interstate 11 (I-11) has a current length of 22.8 miles and runs on a mostly northwest-southeast alignment in Nevada, running concurrently with U.S. Route 93 (US 93) between the Arizona state line and Henderson.
I-11 plans going forward
As first proposed in the 2012 Moving Ahead for Progress in the 21st Century Act, the highway was only authorized from Casa Grande, Arizona, to Las Vegas. This was to provide a Las Vegas-Phoenix freeway link. Phoenix and Las Vegas are the two largest neighboring cities in the United States not connected by an interstate highway.
Further extensions of the I-11 corridor to the north (toward Reno and to the south toward Nogales, Arizona) were approved by the 2015 Fixing America’s Surface Transportation Act.
In addition, the relatively new concept of “megapolitan” urban regions means that I-11 is now considered a key connector to unify the triangle formed by Las Vegas, Phoenix and Los Angeles. The highway triangle consists of I-15 to the north and west, I-10 to the south and I-11 on the east.
The proposed numbering of this highway does not currently fit the normal pattern of the Interstate Highway System (IHS) grid. Currently it would run east of I-15; therefore it should be numbered greater than 15. However, I-17 has already been built east of the I-11 alignment in Arizona. This makes it impossible to fit I-11 Interstate number into the national grid and remain within the traditional numbering system. However, the new plan to extend 1-11 north from Las Vegas to Reno would place that portion of I-11 west of I-15. Therefore, it would fit into the national grid numbering system.
Plans for a longer interstate
Currently the proposed segments of I-11 are tentatively planned to run from Nogales to near Reno, generally following the current routes of I-19, I-10, US 93 and US 95. Two existing highway segments need to be brought up to interstate standards: US 93 in Arizona from Wickenburg to the Nevada state line on the Mike O’Callaghan-Pat Tillman Memorial Bridge over the Colorado River; and US 95 in Nevada from the edge of the Las Vegas Valley to Tonopah. The exact I-11 route has not been determined yet except for these sections; however, several alternatives have been proposed for further study and refinement.
I-11 in Arizona
At this time, the southern end of I-11 will be at the junction with Interstate 19 Business Loop in Nogales, concurrent with that of I-19. Another alternative would be for 1-11 to follow Arizona State Route 189 from its intersection with I-19 to the Mariposa Port of Entry where it continues south as Mexican Federal Highway 15D. This would create a Nogales, Arizona/Nogales, Sonora Metro Area Bypass for high-density CANAMEX Corridor traffic.
As originally planned, I-11 would join I-10 in Tucson and continue to Casa Grande. However, alternatives were studied, and the recommended corridor alternative would split from I-19 near Sahuarita and travel around the Tucson Mountains as a bypass route around Tucson, and then run parallel to I-10 to Casa Grande. Under this plan the two interstates would be within miles of each other; a short connection to I-10 is proposed in Marana.
At or near the interchange with I-8 and I-10 in Casa Grande, Interstate 11 would diverge from I-10 and run in a generally westward and then northward direction as a bypass route around the Phoenix metropolitan area.
North of I-10 in Buckeye or Tonopah, highway planners have identified a general corridor roughly parallel to the Hassayampa River with two more specific corridor alignments.
The highway would then run concurrently with US 93 through northern Arizona, including running concurrently with I-40 in and near Kingman. The highway would then cross the Mike O’Callaghan-Pat Tillman Memorial Bridge into Nevada.
I-11 in Nevada
In Nevada, the highway currently begins at the Arizona state line on the Hoover Dam Bypass, then travels along the 15-mile bypass around Boulder City, which opened on August 9, 2018. It is signed concurrently with US 93 throughout. At mile marker 14, I-11 intersects and joins with US 95 heading north. Continuing northwest, the highway runs along a former 5-mile section of I-515 around Henderson before ending at the Henderson Spaghetti Bowl interchange with I-215 and SR 564.
At this time there are three alternative corridors that have been identified for I-11’s route through the Las Vegas Valley. Highway planners are in the process of determining the most viable option.
History of the route
As recently as 1997, US 93 was primarily a two-lane road in Arizona between Wickenburg and Hoover Dam. It was known for its dangerous curves and hills in the section between Wickenburg and I-40. In the late 1990s, the Arizona Department of Transportation (ADOT) began road construction to widen US 93 to four lanes. Some sections of the roadway were new, while other sections along US 93 were repaved with two new lanes constructed parallel to the original roadway.
Concurrently, Nevada and Arizona began considering what to do about US 93’s crossing of Hoover Dam. This had been a significant bottleneck for regional commerce; the road had hairpin turns, multiple crosswalks for pedestrians and steep grades. After the terrorist attacks of September 11, 2001, plans to construct a bridge to bypass the dam became crucial because the road was closed to trucks. This meant that commercial traffic had to detour through Bullhead City, Arizona, and Laughlin, Nevada, which caused severe transportation delays.
The completion of the Mike O’Callaghan-Pat Tillman Memorial Bridge on October 14, 2010, meant that most of the roadway is now a four-lane divided highway. In addition, the Federal Highway Administration (FHWA) approved the Nevada Department of Transportation’s (NDOT) environmental review of a bypass that would be built around Boulder City and then connect the end of the recently constructed Hoover Dam Bypass bridge east of Boulder City to I-515 west of Boulder City.
On March 21, 2014, Interstate 11 signs were installed along the US 93 corridor. On May 21, 2014, NDOT applied to the American Association of State Highway and Transportation Officials (AASHTO) to create the I-11 designation between the Arizona state line and the I-215/I-515 Interchange in Henderson. AASHTO approved this request, contingent on FHWA approval. During 2017 and 2018 segments of Phase 1 of the new I-11 were opened.
Phase 2 construction began on April 6, 2015 and was completed in August 2018. In March 2019, NDOT replaced I-515 signs along its southernmost five-mile section with signs for I-11.
The Nevada portion of the original I-11 corridor is a full freeway that meets current IHS standards from the Mike O’Callaghan-Pat Tillman Memorial Bridge on US 93 to US 95 northwest of Las Vegas. Although most of US 93 in Arizona has been upgraded to four lanes, some portions of that corridor are not built to IHS standards.
As of last year, Phase 4 is under construction. The US 93 Corridor Improvement Project will finish what was started in 1998 and will connect four sections of the divided highway to Wickenburg, which will allow more traffic on these now-congested roads. In addition, a direct interchange with I-40 and US 93 is planned.
Long-term corridor plans
Earlier, I-11 was projected to serve as an Intermountain West section of the nation’s long-term CANAMEX Corridor. transportation plans, with potential extensions south from Casa Grande to the Sonoran border, and north from Las Vegas through northern Nevada (potentially passing through Reno or Elko) and onward through either eastern Oregon–Washington or western Idaho before terminating at the Canadian border. As of December 2015, I-11 is projected to become the Intermountain West Corridor, extending from Phoenix and Las Vegas through Reno to the Pacific Northwest via central or eastern Oregon and central Washington to the Canadian Border. Feasibility studies for these corridor extensions began in July 2013 and were published in November 2014.