As the beltway passes under I-15, it changes from Interstate to county highway still maintaining freeway status as it heads nearly due west. Passing Decatur Boulevard, two one-way frontage roads (which formerly carried the initial beltway facilities) appear on either side of the highway. At Durango Drive, the roadway curves northward. The frontage roads end as the highway reaches Tropicana Avenue, but the freeway continues briefly west and then north again to intersect Charleston Boulevard (SR 159) near Red Rock Canyon. As it passes north through the community of Summerlin (part of the city of Las Vegas), it meets the Summerlin Parkway freeway at a recently upgraded system interchange.