Interstate 84 (I-84): Both Routes, Miles by State and Safety Data

How long is I-84?

The FHWA Route Log, January 2026 edition, credits I-84 with 965.46 miles, counting both roads. The western road makes up 733.06 of them: 375.68 in Oregon, 275.83 in Idaho and 81.55 in Utah. The eastern road has 232.40: 54.88 in Pennsylvania, 71.41 in New York, 97.90 in Connecticut and 8.21 in Massachusetts. Oregon holds the most I-84 mileage and Massachusetts the least.

Wikipedia puts the western road at 769.62 miles end to end. Most of the gap is in Utah, where I-84 and I-15 share pavement for about 40 miles between the Tremonton area and Riverdale. The Route Log books those 35.98 shared miles to I-15, so Utah shows 81.55 miles in the table against Wikipedia's 118.71. Put the shared miles back and the western road comes to 769.04 Route Log miles. For the eastern road, Wikipedia and Interstate Guide both print 232.71 miles, within a third of a mile of the federal figure. The crash rates further down count the shared Utah stretch, which is why Utah carries 117.53 route miles in that table.

Where I-84 starts and ends

I-84 is really two roads. The western one begins at I-5 and US 30 in Portland, Oregon. East of Troutdale it follows the south bank of the Columbia River for nearly 150 miles, the first 80 inside the Columbia River Gorge National Scenic Area, past Hood River and The Dalles. East of Pendleton it climbs Emigrant Hill on a 6 percent grade into the Blue Mountains, tops out at 4,193 feet and drops to La Grande. Westbound, the lanes switchback twice on the way down into Pendleton. It crosses the Snake River at Ontario into Idaho, passes Caldwell, Nampa, Meridian and Boise in the Treasure Valley, then passes Mountain Home and skirts Twin Falls. In Utah it joins I-15, splits off again at Riverdale near Ogden, and follows the Weber River up Weber Canyon past Devil's Slide to end at I-80 and US 189 in Echo.

The eastern road starts at I-81, I-380 and US 6 in Dunmore, Pennsylvania, just east of Scranton, and crosses the Poconos lake region. South of Port Jervis a long bridge takes it over the Delaware and Neversink rivers into New York, and the Newburgh-Beacon Bridge carries it across the Hudson. In Connecticut it is the Yankee Expressway through Danbury and Waterbury, where it rides an elevated viaduct with eastbound and westbound traffic on different levels. It curves north of downtown Hartford to meet I-91 beside the Connecticut River, becomes the Wilbur Cross Highway, and ends at a trumpet interchange with the Massachusetts Turnpike, I-90 exit 78, in Sturbridge.

Interstate junctions along I-84

The list starts in Portland and reads west to east, finishing the western road before it picks up the eastern one at Dunmore. Out west, I-84 meets I-5, I-82 near Hermiston, I-86 near Burley in Idaho, I-15 twice in Utah where the shared stretch begins and ends, and I-80 at Echo. Back east it meets I-81 at its starting point, I-87 in New York, I-91 in Hartford and I-90 at Sturbridge. That makes nine different Interstates. Three-digit spurs such as I-205 in Portland and I-184 in Boise do not appear in the list.

Fatal crashes on I-84

From 2020 through 2024, crashes on the I-84 main line killed 304 people on the two roads combined, or about 61 a year. Divided by route miles, I-84 averages 6.1 deaths per 100 miles a year against an Interstate-wide 9.5, which puts it 39th of 56 ranked routes. The worst year was 2021 with 76 deaths. The other four years ranged from 52 to 62.

The western road's three states recorded 185 of the deaths. Utah's rate of 1.7 is the lowest on I-84, with Oregon at 4.8 and Idaho at 6.2. The eastern road had 119 deaths on far fewer miles. Connecticut's 97.90 miles saw 82 of them, a rate of 16.8, and Hartford County alone had 53, more than any other county on either road. New York's rate is 7.3 and Pennsylvania's is 2.6. Massachusetts had 4 deaths on 8.21 miles, too short a stretch for a rate. Behind Hartford, the counties with the most deaths are Multnomah, Oregon, which includes Portland (24), Elmore, Idaho (23), Umatilla, Oregon (20) and Ada, Idaho, home to Boise (19).

Counties with the most I-84 crash deaths

Bridges on I-84

I-84's main line rides over 721 bridges in the 2025 National Bridge Inventory, with a median construction year of 1967. Of those, 158 rate Good, 536 Fair and 27 Poor, about 3.7 percent. New York accounts for 18 of the Poor ratings with only 94 bridges, the highest share in any I-84 state. Oregon has the most bridges, 206, and just one rates Poor. Connecticut and Utah have 4 each, and Idaho, Pennsylvania and Massachusetts have none.

In Waterbury, Connecticut, I-84 meets Route 8 at the interchange known as the Mixmaster. CTDOT is studying two designs to replace it. Recent estimates run from about $3 billion to more than $5 billion, and the state says full replacement will take decades.

Tolls on I-84

FHWA's January 2023 toll inventory lists a single facility on I-84: the Newburgh-Beacon Bridge over the Hudson River, run by the New York State Bridge Authority. It collects from eastbound traffic only. A full eastbound trip on the eastern road pays that one toll, collected electronically: $1.65 for a car with E-ZPass or $2.15 by Tolls by Mail, according to the New York State Bridge Authority. Westbound drivers pay nothing. The 2.70 miles in the table describes the bridge facility as FHWA records it. The western road through Oregon, Idaho and Utah has no tolls.

I-84 auxiliary routes

Three spur routes carry the 84 number. I-184 runs 3.57 miles into Boise. In Connecticut, I-384 covers 8.20 miles from Hartford through East Hartford to Manchester, along the line once meant for I-84's extension toward Providence. I-684 is the longest at 28.47 miles in New York, serving White Plains, plus 1.41 miles in Connecticut.

Why two highways share the number 84

The western road did not start out as I-84. A 1939 Bureau of Public Roads report proposed the corridor as a toll superhighway, and when it joined the Interstate system in 1956 it was first slated to be I-82, a number it never carried on signs. The 1958 plan called it I-80N, partly to pair it with US 30. In Portland, plans for the Mount Hood Freeway were dropped in 1974 after a freeway revolt. AASHTO voted on July 7, 1977, to renumber I-80N as I-84 and gave the states until July 1, 1980, to change the signs, which went up in 1980. The Portland section is still called the Banfield Freeway, after Thomas H. "Harry" Banfield, who chaired the Oregon State Highway Commission until 1950.

The eastern road has carried the number since August 14, 1957. New York's last piece, 6.7 miles from Newburgh to Maybrook, opened on July 2, 1971, and Pennsylvania's final link was completed on December 6, 1977. In 1972 I-84 was extended west along the new I-380 to reach I-81 at Dunmore. East of Hartford, planners shifted the route toward Providence, Rhode Island, in 1969, and the road from East Hartford to Sturbridge carried the I-86 number until 1984. The Providence freeway was never finished, partly over concerns about the Scituate Reservoir. AASHTO dropped I-84 from Rhode Island on October 1, 1983, and on May 23, 1984, returned the number to the Sturbridge alignment, retired that I-86 and created I-384.

I-84 traffic and road conditions

Closures and crashes on I-84 change by the hour. Each state posts them on its own 511 or traveler page; Oregon, Idaho and Utah come first below, followed by the four eastern-road states.

I-84 questions