Interstate 90 in Washington


Get started Seattle
End Spokane
Length 297 mi
Length 478 km
  • 2 → Seattle / Olympia3 Rainier Avenue
  • Interstate 90 Floating Bridges
  • 6 Mercer Way
  • 7 Island Crest Way
  • 8 Mercer Way
  • 9 Bellevue Way
  • 10 → Seattle Bypass
  • 11 Downtown Bellevue
  • 13 Lakemont Boulevard
  • 15 Renton Road
  • 17 Front Street
  • 18 Highlands Drive
  • 20 High Point Way
  • 22 Presotn
  • 25
  • 27 North Bend Way
  • 31 North Bend
  • 32 Tanner
  • 34 Twin Falls
  • 38 Olallie State Park
  • 42NF-55
  • 45 Bandera State Airport
  • 47 NF-55
  • 53 Snoqualmie Pass
  • 54 Snoqualmie Pass
  • 62 NF-54
  • 63 NF-4826
  • 70 Easton State Airport
  • 71 Easton
  • 74 Nelson Siding Road
  • 78 Golf Course Road
  • 80 Bullfrog Road
  • 84 West Cle Elum
  • 85 East Cle Elum
  • 93 Sunlight Drive
  • 101 Thorp
  • 106 West Ellensburg
  • 109 Ellensburg
  • 110 → Yakima / Boise
  • 115 Kittitas
  • 136 Vantage
  • Columbia River
  • 137 Royal City
  • 143 Silica Road
  • 149 George
  • 151 Ephrata
  • 154 Adams Road
  • 164 Dodson Road
  • 169 Hiawatha Road
  • 174 Westshore Drive
  • 176 Moses Lake
  • 179 East Moses Lake
  • 182 Road O
  • 184 Road Q
  • 188 Road U
  • 196 Deal Road
  • 206 Lind
  • 215 Paha Packard Road
  • 221 → Kennewick
  • 221 Ritzville
  • 226 Schoesler Road
  • 231 Danekas Road
  • 245 Sprague
  • 254 Sprague Highway Road
  • 257 Tyler Cheney Highway
  • 264 Salnave Road
  • 270 Four Lakes
  • 272 Aero Road
  • 276 Spokane Airport
  • 277
  • 279
  • 280 Downtown Spokane
  • 281
  • 282 University
  • 283 Freya Street
  • 285 Appleway Boulevard
  • 286 Broadway Avenue
  • 287 Millwood
  • 289 Spokane Valley
  • 291 Evergreen Road
  • 293 Barker Road
  • 294 Appleway Avenue
  • 296 Liberty Lake
  • 299 State Line
  • Idaho

Interstate 90 or I -90 is an Interstate Highway in the U.S. state of Washington. The highway is the most important east-west connection in the state, mainly connecting the largest city of Seattle with the major city of Spokane to the east. The scenery on the route varies widely, from the urban and suburban landscapes of Seattle, to the forested mountains of the Cascade Range, and the arid steppe and deserts east of this mountain range. I-90 is 478 kilometers long in Washington.

  • Features what is the best time to travel to the state of Washington.

Travel directions

The Interstate 90 Floating Bridges in Seattle.

I-90 over the Columbia River at Vantage.

I-90 in Spokane.


Interstate 90 begins on the south side of downtown Seattle. Seattle is a large city with more than 700,000 inhabitants, and 3.8 million in the metropolitan area. The access roads do not begin at the Interstate 5 interchange, but continue a little further west at Seahawk Stadium and Safeco Field, sports arenas. Shortly after the interchange, the highway dives through a tunnel, under residential areas, and then directly onto Interstate 90 Floating Bridges, a floating bridge. In total there are 8 lanes hereavailable. After this, I-90 crosses Mercer Island, with the suburb of the same name on it. South of Bellevue, one of the largest suburbs with 110,000 inhabitants, the highway crosses the lake again via a short bridge. This is followed by a 4-level stack interchange with Interstate 405, the eastern bypass of the metropolitan area.

  • FINDJOBDESCRIPTIONS: Weather by month for the state of Washington, covering average temperatures for all 12 months.

The highway then runs through the suburbs on the east side of the city, passing by Lake Sammamish. Because the mountains follow fairly quickly after Seattle, the suburbs have stretched out mainly in the north-south direction, after 15 miles you pass the last suburb, Issaquah. The road here leads directly through forested mountain slopes, with occasional views of Mount Rainier, the highest point in the state at 4,392 meters.

Cascade Range

Now begins a long climb to Snoqualmie Pass, the highest point in the Cascades. One has to climb 900 meters over 60 kilometers here. The highway runs through a spectacular valley with beautiful views of the mountains. At milemarker 53 you pass Snoqualmie Pass, the highest point of the highway in the Cascades at 922 meters. After this begins a long descent to the plains in eastern Washington. Just before Ellensburg you enter a completely different landscape, desert-like with canyons and less vegetation. You drive through the valley of the river Yakima, which is still somewhat cultivated with agricultural areas. Despite the semi-desert landscape, the winter weather can be quite surprising, severe winters with lots of snowfall are no exception along Interstate 90. South of Ellensburg, a regional town, theOff Interstate 82, a relatively short highway to Yakima, Richland and Interstate 84 to Boise and Salt Lake City, which are still a long way off.

Eastern Washington

From Ellensburg begins the long drive to Spokane, the next major city, which is another 275 kilometers to the east. The landscape consists of low hills with little vegetation. At the height of the hamlet of Vantage one crosses the wide Columbia River. The river is a mile wide here. East of this river is a large irrigated agricultural area, which is made possible by the many dams built in the river. Near Moses Lake, the agricultural areas suddenly turn into sand dunes. A little further on it suddenly changes into agricultural areas again.

At Ritzville, US 395 joins in, a major highway through the western United States. The route is double-numbered here as far as Spokane, 100 kilometers to the northeast. The route here also turns more towards the northeast. The last 100 miles to Spokane is lonely, with only very sporadic villages. The area is also largely uncultivated. Just before Spokane you pass two airports, Spokane Airport and Fairchild Air Force Base. After this, US 2 merges and the road widens to 2×3 lanes. Shortly after, US 195 turns off, a main road to Lewiston in Idaho, heading south. After this you soon arrive at the center of Spokane, this city has mainly expanded towards the east. The road runs over a large viaduct over the city. East of the center is a very large industrial area, with residential areas to the north and south. The largest suburb is Opportunity. The urban area extends to the state border withIdaho.


In 1927, the first bridge over the Columbia River at Vantage opened to traffic. The bridge was replaced in the 1960s when I-90 was built. The bridge was then moved to Lyons Ferry where the bridge then spanned the Snake River.

The first part of what would later become I-90 was the Interstate 90 Floating Bridges, a floating bridge on Lake Washington. It opened to traffic on 2 July 1940. However, the second bridge did not open until June 4, 1989. In 1940, the Mount Baker Tunnel near downtown Seattle also opened to traffic. The I-90 was mainly built in the 1960s. In 1969, I-90 over Snoqualmie Pass east of Seattle opened to traffic. However, there were legal problems for the construction of I-90 at Bellevue. This part was only opened to traffic in the early 1990s. In 1981 and 1988, the East Channel Bridge between Mercer Island and Bellevue was replaced by two new bridges.

Between 2009 and 2018, a 15-mile stretch east of Snoqualmie Pass was widened to 2×3 lanes, partly on new flyovers. The project cost $551 million. On August 10, 2015, the first half of a new avalanche overpass opened along Keechelus Lake.

Reversible lane

The interchanges of I-90 in Seattle.

I-90 near Snoqualmie Pass.

I-90 has a two-lane interchange between I-5 in Seattle and I-405 in Bellevue. Part of the switch lane is only for HOV (carpool & public transport), although the crucial middle part is open to all vehicles. There are no tolls on the interchange lane like many other express lanes in the United States. The alternate lane on I-90 is also called an express lane. This is usually in use towards the west in the morning and towards the east in the afternoon. The alternating lane is usually switched between 12:30 and 14:00. The conversion is done manually with a chimney, and takes about 1 hour.

Traffic intensities

The Seattle area is quite busy with up to 150,000 vehicles per day. After the agglomeration this drops to about 30,000 vehicles, after the I-82 it is even lower with 12,000 vehicles. Only just before Spokane do the intensities rise again, to 114,000 vehicles per day. 48,000 vehicles cross the Idaho border every day.

Interstate 90 in Washington

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