[2][3] The latter name alludes to the highway's original purpose of bypassing the urbanized areas of Santa Fe and thereby relieving it from shipments of hazardous waste.

North of the freeway, NM 599 briefly enters La Cienega, a census-designated place, and crosses West I-25 Frontage Road, which provides access to a horse racetrack (formerly known as Downs at Santa Fe).

Northwest of the frontage road, the speed limit increases from 45 to 65 mph (70 to 105 km/h) for approximately two miles (3.2 km), as the expressway turns to the north and leaves La Cienega.

[4] As the highway leaves the industrial and residential area near the intersection with Airport Road, the speed limit increases to 55 mph (90 km/h) as the expressway curves to the northeast and crosses the Santa Fe River.

Continuing northeast the expressway begins a long moderate climb through rolling terrain with grasses and juniper shrubs punctuated by mostly light residential development, as the road follows (at a distance) Santa Fe's northwestern boundary, until it reaches a dumbbell interchange (Exit 6) with South Meadows Drive (CR 62).

[4] Beyond the Camino La Tierra/Paseo Nopal interchange, the expressway assumes a more east–northeasterly course, re-enters the city limits of Santa Fe, and passes through largely open space (that is projected to be developed).

After an intersection with Camino De Las Montoyas the route turns to the south–southeast and reaches its highest point at a diamond interchange (unnumbered exit) with Ridgetop Road.

As the expressway crosses under Ridgetop Road the speed limit decreases to 45 mph (70 km/h) and the highway descends promptly into a canyon named Cañada Rincon.

Much of the funding for construction of the route was supplied by the United States Department of Energy so that WIPP-bound waste from LANL would not have to pass through the center of Santa Fe.