Interstate 5 in Oregon
Interstate 5 in the U.S. state of Oregon is a major Interstate Highway that traverses the state from north to south. It travels to the west of the Cascade Mountains, connecting Portland to Salem, Eugene, Medford, and other major cities in the Willamette Valley and across the northern Siskiyou Mountains. The highway runs from the California state line near Ashland to the Washington state line in northern Portland, forming the central part of Interstate 5's route between Mexico and Canada.
I-5 was designated in 1957 and replaced U.S. Route 99 for most of its length, itself preceded by the Pacific Highway and various wagon roads. The freeway incorporated early bypasses and expressways built for US 99 in the 1950s, including a new freeway route from Portland to Salem, and additional bypasses were built using federal funds. The last segment of I-5, on the Marquam Bridge in Portland, was opened in October 1966 and the whole highway was dedicated later that month. The freeway remains parallel or concurrent to Oregon Route 99 and its spur routes, running along former segments of US 99 that were bypassed by I-5, from Ashland to Portland.
Under Oregon's named route system, all of I-5 is designated as Pacific Highway No. 1. The Salem–Portland section was named the Baldock Freeway until 2022. The freeway also has three signed auxiliary routes that function as spurs and bypasses of major cities: I-105 in Eugene, I-205 in eastern Portland, I-405 in downtown Portland. Two additional auxiliary routes were planned in the early years of the Interstate system, but were shelved after local opposition.
Route description
Interstate 5 is the second-longest freeway in Oregon, at, and is the only Interstate to traverse the state from north to south. The highway connects several of the state's largest metropolitan areas, which lie in the Rogue and Willamette valleys, and passes through counties with approximately 81 percent of Oregon's population. As a component of the Interstate Highway System, I-5 is also designated as an important highway under the National Highway System. It is officially designated under Oregon's named route system as the Pacific Highway No. 1, a name shared with Oregon Route 99 and its split routes north of Junction City. OR 99 runs concurrent to I-5 through most of southern Oregon, splitting from the freeway to serve city centers and use other alternate routes, while OR 99W and OR 99E serve corridors on opposite sides of the Willamette River. The state legislature also designated I-5 as the Purple Heart Trail and Korean War Veterans Memorial Highway in 2015.I-5 is maintained by the Oregon Department of Transportation, who conduct an annual survey of traffic volume that is expressed in terms of annual average daily traffic, a measure of traffic volume for any average day of the year. The highway's busiest section is near Durham between junctions with I-205 and OR 217, carrying an average of 164,000 vehicles daily in 2017. The least-traveled section of I-5 is located near Ashland and carries only around 16,600 vehicles daily.
California to Eugene
I-5 enters Oregon at the California state line in southern Jackson County. The highway travels northeast along a ridge in the Siskiyou Mountains, with a maximum grade of 6 percent, to Siskiyou Summit; at, it is the highest point on all of I-5 and one of the highest points on the Interstate system. The mountainous, section of the freeway runs along Siskiyou Pass and includes several runaway truck ramps and chain-up areas due to its heavy use by trucks and its foggy and snowy conditions in winter. North of the summit, the freeway intersects the Old Siskiyou Highway and the Pacific Crest Trail before it travels out of the Rogue River–Siskiyou National Forest.The highway descends from the mountains into the Rogue Valley and intersects the south end of OR 99 west of Emigrant Lake, adjacent to a railroad underpass. I-5 follows OR 99 and passes a rest area and welcome center before entering the city of Ashland. The freeway crosses OR 66 west of the city's municipal airport and follows Bear Creek around the north side of downtown Ashland. I-5 and OR 99 run parallel each other on opposite sides of Bear Creek through Talent and Phoenix to Medford, at the center of the Rogue Valley and its winery region. The freeway runs through downtown Medford on a elevated viaduct with no exits to the city center. It then intersects OR 62 at the Rogue Valley Mall, providing access to Crater Lake and Mount McLoughlin northeast of the valley. The freeway continues northwest, passing Rogue Valley International–Medford Airport and the suburb of Central Point before turning west to follow the Rogue River.
I-5 follows the Rogue River downstream through a narrow valley, where OR 99 and a railroad cross over and under the freeway several times, and passes Valley of the Rogue State Park. It also passes the Oregon Vortex, a popular roadside attraction near Gold Hill. At the west end of the valley in Josephine County, the freeway reaches Grants Pass and intersects U.S. Route 199, which connects to Crescent City, California, on the Pacific Coast. The freeway continues along the northeast edge of Grants Pass and becomes concurrent with OR 99 at an interchange north of the city. I-5 splits from the Rogue River and continues north along a zig-zag course across several passes and valleys in the Southern Oregon Coast Range. At Wolf Creek, it passes a historic inn and tavern that is listed on the National Register of Historic Places. The freeway crosses into Douglas County near Stage Road Pass east of Glendale and turns northeast to follow the Cow Creek valley before resuming its northern course through the mountains. After descending from Canyon Creek Pass and following Canyon Creek, I-5 reaches Canyonville and passes the Seven Feathers Casino Resort. The freeway follows the South Umpqua River through Myrtle Creek and the Cow Creek Reservation, with OR 99 splitting to serve Winston. I-5 intersects OR 42 east of Winston in Green and continues north into the outskirts of Roseburg.
Within Roseburg, the freeway runs along the west bank of the South Umpqua River opposite from the city's downtown and passes through several residential neighborhoods near the regional airport. At Harvard Avenue, I-5 begins a concurrency with OR 138 that continues for to Sutherlin, running parallel to OR 99 as the highways cross the North Umpqua River. OR 99 rejoins I-5 between Oakland and Yoncalla in the Cabin Creek canyon, but splits off again to serve the Pass Creek valley while I-5 remains in the Pleasant Valley. The two highways are rejoined at Anlauf and continue northeast along Pass Creek towards Cottage Grove in Lane County. The freeway runs through the eastern outskirts of Cottage Grove and continues north along the Coast Fork Willamette River into the Willamette Valley, trading the mountainous terrain of southern Oregon for rolling hills and farms. At Goshen, I-5 intersects OR 58 and passes the Lane Community College campus before entering Eugene.
Eugene to Wilsonville
I-5 continues north into Eugene, running along the city's eastern border with Springfield, and intersects OR 225 at Coryell Pass. OR 99 then splits from the freeway and travels west along OR 126 Business into downtown Eugene, serving the University of Oregon campus, and continues north to Junction City, where it splits into OR 99W and OR 99E. The freeway then travels over the Whilamut Passage Bridge, a pair of concrete arch bridges that span across the Willamette River west of downtown Springfield. On the north side of the river near the Gateway Mall, it intersects I-105, providing freeway access to downtown Eugene, and OR 126. At the north end of Eugene, intersects Beltline Road in a partial cloverleaf interchange with direct ramps to the western freeway, which carries OR 569 around Eugene.The freeway leaves Eugene after crossing the McKenzie River at Armitage Park south of Coburg. I-5 continues north along OR 99E through rural Linn County, intersecting OR 228 near Brownsville and OR 34 west of Lebanon, before the two highways reach Albany. The freeway skirts the east side of the city, where it intersects US 20, and begins a concurrency with OR 99E. I-5 and OR 99E then intersect the south and north ends of OR 164 near Millersburg and the Ankeny National Wildlife Refuge. The freeway continues northeast and passes the Enchanted Forest amusement park and several wineries before reaching the southern outskirts of Salem.
The freeway travels around McNary Field and intersects OR 22 at Mission Street, near the Corban University campus southeast of downtown Salem. I-5 and OR 99E continue north through suburban Salem, passing the Oregon State Penitentiary and Oregon State Hospital campus, which is located east of the Oregon State Capitol and Willamette University. Between the Willamette Town Center shopping mall and the Oregon State Fairgrounds, the freeway intersects the south end of OR 213, a local highway that parallels I-5 to the east towards the Portland area. OR 99E splits from I-5 at an interchange with Portland Road, located west of the Chemeketa Community College campus in Hayesville. The freeway continues northwest into Keizer and intersects Salem Parkway, a divided highway carrying OR 99E Business, at an interchange that straddles the 45th parallel.
I-5 continues northeast from the interchange, passing the Keizer Station complex and the minor-league Volcanoes Stadium before leaving the suburban fringes of Keizer. The freeway continues north entering the French Prairie region of the Willamette Valley along OR 99E and the former Oregon Electric Railway, passing the Powerland Heritage Park and Oregon Electric Railway Museum near Brooks. At the Woodburn Premium Outlets mall west of Woodburn, I-5 intersects the dual termini of OR 214 and OR 219, which provide access to Silverton and Newberg, respectively. It reaches a junction with OR 551 north of Aurora State Airport and adjacent to the French Prairie rest area, which includes a solar power array with 7,000 panels. North of the interchange, I-5 crosses the Willamette River on the Boone Bridge and enters the city of Wilsonville, at the edge of the Portland metropolitan area.