The Nevada Department of Transportation (NDOT) and the Regional Transportation Commission of Southern Nevada (RTC) in the US are jointly developing the Interstate 11 Boulder City Bypass, which will connect Las Vegas with Phoenix.

The project includes the construction of a four-lane road with interchanges at I-11/US 95 and I-11/US 93. It also includes reconfiguration of the interchange at the US 93/State Route 172 Hoover Dam Exit.

Final environmental impact statement for the 15.5-mile (25km) project was completed in 2005. Ground-breaking for the first phase of the project was conducted in April 2015, while the construction is scheduled to be completed by January 2018. Construction of the phase two of the bypass began in 2015, while completion is scheduled for October 2018.

The $318m freeway project construction is being undertaken in two phases and expected to create approximately 4,000 direct and indirect jobs in the region.

Interstate-11 Boulder City Bypass details

The freeway connecting Las Vegas and Phoenix was designated as Interstate 11 under the 2012 surface transportation reauthorisation programme, also known as the Moving Ahead for Progress in the 21st Century Act (MAP-21).

“The $318m freeway project construction is being undertaken in two phases and expected to create approximately 4,000 direct and indirect jobs in the region.”

Concrete pavement was opted for the project instead of asphalt due to its longevity, a step that is also expected to reduce 13-28% in maintenance costs in the long-run.

The project will also construct a Northbound Truck Climbing Lane, Southbound Scenic Vista Parking Area, and ten new bridge structures. 

The visual elements of the project will include the construction of a 1,200ft-long, 28ft-wide, cast-in-place textured, multi-coloured concrete wall, which will be coated with an anti-graffiti film and feature graphics highlighting the construction of Hoover Dam.

Despite containing lower levels of naturally occurring asbestos (NOA) concentrations, RTC and NDOT will utilise EPA-recommended mitigation measures throughout the project to minimise exposure to dust potentially containing NOA. They will also conduct air monitoring to ensure the effectiveness of the mitigation measures throughout the construction stage.

Two-phased development

The first phase of the two-phased development project will include the construction of a 2.5 mile-long, four-lane concrete interstate freeway between Silverline Road and Foothills Drive.

The completion of the first phase will minimise traffic congestion, enhance safety, and increase travel and commerce between Arizona and Nevada. In addition, a full diamond interchange at Railroad Pass will be constructed with a loop ramp.

Other components of the phase will include the construction of a 1.5-mile (2.4km) asphalt frontage road linking Henderson with the Railroad Pass interchange, replanting 20,000 cactuses, placing decorative rock, and installing five miles (8km) of tortoise fencing.

The second phase includes the construction of 12.5-mile (20.1km) section from I-515 to US 93 near the new Hoover Dam Bypass Bridge. It will link the project from Silverline Road to the Nevada Interchange, which was developed as part of the Federal Highway Administration’s Hoover Dam Bypass project.

The second phase is being constructed by RTC, but NDOT will take over the maintenance responsibility upon completion.

Construction details

As of February 2017, Fisher Industries completed 62% of the project while LVP completed 90% of the grading, started construction of nine bridges out of 11, and excavated more than five million cubic yards of rocks.

LVP completed 65% of the work on the second phase of the project by the end of 2016.

In 2014, the RTC entered agreements with the Western Area Power Administration (Western) and the Colorado River Commission (CRC) to relocate their electrical transmission facilities, which come in the way of the Bypass alignment.

As of February 2015, Western relocated all their facilities, while CRC relocated its facilities by June 2015.


Expected to cost $83m, the first phase will be completed using $68m in federal funding and $10m of RTC/FRI funds (Fuel Revenue Indexing), while the remaining $5m will be funded by the state.

The US Federal Government will provide $181.2m for the $235m second phase, while the FRI will provide the remaining $53.8m.

Contractors involved with the I-11 Boulder City Bypass

Fisher Sand and Gravel won a $83m contract in October 2014 for the first phase of the project.

Las Vegas Paving won the design-build contract for the second phase works in January 2015. CA Group was engaged as the lead engineer for the phase two.