Interstate 84 is an unusual interstate: it consists of two non-contiguous segments. The western segment runs 770 miles from Portland, Oregon to Echo Junction, Utah (where it terminates at I-80). The eastern segment runs 233 miles from Dunmore, Pennsylvania across New York and Connecticut to Sturbridge, Massachusetts (where it terminates at I-90). The two segments are not connected and serve completely different regions.
For freight, the western I-84 is the principal alternative to I-90 for Pacific Northwest traffic moving inland, particularly for produce and lumber from the Columbia Basin and the Snake River plain. It traces the route of the Oregon Trail and is the only interstate connection between Portland and the Salt Lake City freight hub. The eastern I-84 is a short connector linking the I-80 corridor in Pennsylvania to Boston via Hartford.
Geographically the western segment includes some of the most challenging interstate terrain in the country: the Columbia River Gorge (with severe crosswinds and ice events), Cabbage Hill / Deadman Pass in Oregon (a sustained 6% grade), the Blue Mountains, and the Snake River Canyon. The eastern segment is mostly rolling New England terrain.
- Two non-contiguous segments: western (OR-ID-UT) and eastern (PA-NY-CT-MA)
- Western segment follows the historic Oregon Trail
- Includes Cabbage Hill / Deadman Pass (OR), one of the steepest interstate grades
- Crosses the Columbia River Gorge with severe crosswind exposure
- Eastern segment connects I-80 in PA to I-90 in MA via Hartford
- Western segment is toll-free; eastern is mostly toll-free
- Combined length of both segments: approximately 1,000 miles