Background

Among Horrocks' most compelling redesigns because of its uniquely tailored functionality is the I-15/US-93 Garnet Modified Diverging Diamond Interchange (IDDI), north of Las Vegas, Nevada. A high volume of truck traffic prompted the effort; an almost steady stream of traffic was utilizing the intersection to access US-93, where Nevada's busiest truck stop is located, as well as access to the city landfill.

Project Details

Building on an existing diamond interchange, where traffic crosses to the opposite side of the roadway to allow uninhibited left and right turns, Horrocks added several free-flowing ramps to enhance efficiency allowing trucks to enter and exit I-15 without stopping. The redesign also included multiple bridge replacements and access improvements, resulting in significantly reduced travel times. The project also included major drainage improvements, structure innovations, and landscaping and aesthetics, enhancing more than just efficiency in this highly used transport corridor in southern Nevada.  

Outcomes

This uniquely modified interchange now accommodates an unusually high level of freight traffic with ease and provides efficient access to adjacent industrial and manufacturing enterprises, which are vital to the growing economy in Clark County. landscaping and aesthetic enhancements contribute to the surrounding area's cultural value and appeal, creating a significant asset to the country's infrastructure. Modifying an already innovative interchange to further enhance efficiency, Horrocks created a design yielding significant benefits in safety and mobility for the traveling public and those executing important county services.

Awards:

International Partnering Institution (IPI), Partnered Project of the Year, 2019