Interstate 5

Interstate 5 Main route of the Interstate Highway System
Length:	1381.29 mi[1] (2222.97 km)
Formed:	1957[citation needed]
South end:	MX 1 at Mexican border in San Ysidro, CA
Major junctions:	I-8 in San Diego, CA I-10 in Los Angeles, CA I-80 in Sacramento, CA I-84 in Portland, OR I-90 in Seattle, WA
North end:	BC 99 at Canadian border in Blaine, WA
Wikimedia Commons has media related to: Interstate 5

Interstate 5 (abbreviated I-5) is the westernmost interstate highway in the contiguous United States. Its odd number indicates that it is a north-south highway. Its southern terminus is at the international border between the United States and Mexico in the San Diego community of San Ysidro, California. Its northern terminus is at the international border between the United States and Canada at the Peace Arch in Blaine, Washington. I-5 is the only Interstate highway to touch both the Canadian and Mexican borders. At its southern end, I-5 continues into adjacent Tijuana as Mexico Federal Highway 1. On its north side, I-5 continues into Vancouver, Canada as Highway 99.

This highway links to control cities in California (San Diego, Santa Ana, Los Angeles, San Francisco, Sacramento, and Redding), Oregon (Medford, Eugene, Salem, and Portland), and Washington (Tacoma, Seattle, Everett, Mount Vernon, Bellingham). Vancouver, British Columbia, Canada, is also a control city on Interstate 5 from the Seattle-Tacoma area to the north terminus at the Canadian border.

Notably, a control city not directly linked by this highway is San Francisco, which is about 80 miles (130 km) west of I-5. To the south, Interstate 580 splits from I-5 towards San Francisco, while, to the north, Interstate 505 cuts south to Interstate 80, which serves that city. That routing, via I-580, I-80 and I-505, was once Interstate 5W.^{[citation needed]}

Along with Interstate 15, Interstate 10, Interstate 8, Interstate 40, and U.S. Route 101, I-5 serves as one of the primary roads that link the Los Angeles/San Diego Metropolitan areas north and east to the rest of the nation.

Route description

California

Main article: Interstate 5 in California

Interstate 5 starts at the United States-Mexico border at the San Ysidro border crossing, one of the busiest in the world.^[2] Starting at the border in San Ysidro, which is part of the city of San Diego, as the John J. Montgomery Freeway, I-5 goes through the suburbs of National City and Chula Vista before reaching downtown San Diego. It then parallels the Pacific coastline, going through the northern suburbs of San Diego, bisecting the University of California, San Diego campus, before passing through the 28 miles (45 km) of Marine Corps Base Camp Pendleton in northern San Diego County.

At Dana Point, I-5 turns inland and heads due north through Mission Viejo to the El Toro Y interchange in southeastern Irvine. I-5 becomes the Santa Ana Freeway as it runs southeast to northwest, passing through major cities and suburbs in Orange and Southern Los Angeles counties. Many times, Angelinos refer to it as "the 5".

When the freeway reaches the East Los Angeles Interchange one mile (1.6 km) east of downtown Los Angeles, I-5 becomes the Golden State Freeway. For about a four-mile (6 km) stretch between Pyramid Lake and the Santa Clarita Valley, the northbound and southbound lanes separate and actually invert, with the southbound lanes being to the east of the northbound ones. The route continues through the San Fernando Valley and then crosses the Newhall Pass through the Santa Susana Mountains into the Santa Clarita Valley. From there, the Golden State Freeway sharply rises to the north through the Grapevine to eventually cross the Tejon Pass through the Tehachapi Mountains with Path 26 power lines generally paralleling the freeway. The freeway then sharply descends for 12 miles (19 km) from over 4,100 feet (1,250 m) at Tejon Pass to around 1,600 feet (488 m) at Grapevine near the southernmost point of the San Joaquin Valley, approximately 30 miles (50 km) south of Bakersfield and 4 miles (6 km) south from where State Route 99 splits away from it in Wheeler Ridge. On the steep section, trucks heading north (downhill) are restricted to a single lane and by a speed limit equal to approximately half of the speed limit that applies to cars. On the southbound (uphill) side of this same section, a sign at the bottom instructs drivers to turn off air conditioners to prevent overheating, and water is provided on a ramp at that exits the main road on the right side at the top of the hill.

I-5 south approaching Weed and Mt. Shasta.

From Highway 99 to south of Tracy, I-5 skirts along the far more remote western edge of the great Central Valley, and thus here is removed from population centers such as Bakersfield and Fresno with other state highways providing connections. Interstate 580 splits off from I-5 at a point south of Tracy, providing a loop-route connection to the San Francisco Bay Area. After passing Tracy, I-5 heads due north through Stockton and Sacramento before turning due west to Woodland. At Woodland, the interstate heads northwest again towards Dunnigan, where it converges with Interstate 505.

From Dunnigan, I-5 skirts north along the western edge of the Sacramento Valley to Red Bluff. I-5 then enters the Shasta Cascade region, passing through Redding and Shasta Lake before climbing up to near the foot of Mount Shasta. The interstate then travels to Weed and Yreka before reaching the Oregon border.

Oregon

Main article: Interstate 5 in Oregon

About 3 miles (5 km) north of the California border, the highway crosses 4,310 foot (1,314 m) Siskiyou Summit, the highest point on I-5. Dropping down into Rogue River valley through Oregon's southern mountains and towns such as Ashland, Medford, and Grants Pass. Turning north across three passes to the Umpqua Valley and through Roseburg, the mountains tend to turn into hills, and as it reaches Cottage Grove, the road enters the Willamette River Valley. At Eugene the highway intersects with the short Interstate 105. The interstate then heads almost due north, skirting Albany and Corvallis, and passes through Salem. There were plans to build a spur into Salem, Oregon, called Interstate 305.

In downtown Portland, I-5 runs adjacent to the Willamette River and passes by the Rose Garden Arena (center), and Oregon Convention Center (right).

Just north of Salem, between mile marks 259 and 260 (closer to 260), placed in the median is a sign where the 45th parallel crosses I 5. It bears the words "45 Parallel half way between the Equator and the North Pole".

The highway then tracks a little to the northeast, Interstate 205 splits off south of the Portland metro area. From here it passes up through Tualatin and Tigard along former U.S. Route 99W before hitting the southern terminus of I-405 and the Marquam Bridge. Also planned was a spur in Portland off of I-405, called Interstate 505, but it was never built and has been removed from city plans. A stub of I-505 exists as a long exit ramp to U.S. Route 30.

After crossing the Willamette River on the Marquam Bridge, I-5 has junctions at the western terminus of Interstate 84 and the northern terminus of I-405. It then continues through the northern parts of the city of Portland, and crosses into Washington via the Interstate Bridge.

I-5 bridge over the Nisqually River, near Tacoma, Washington

Interstate 5, looking north from Two Union Square in Seattle, Washington.

Washington

Main article: Interstate 5 in Washington

The highway begins in Washington over the Columbia River and drops down into the city of Vancouver. About seven miles (11 km) into the state, it reaches the northern terminus of I-205, which is on the eastern edge of the Portland-Vancouver metropolitan area. It then tracks north by northwest to Kelso and Longview, Washington, at which point it ceases paralleling a large bend of the Columbia. Continuing north through the Willapa Hills, the freeway eventually reaches Olympia, where it bends sharply east, after that it goes through Fort Lewis and by McChord AFB, then finally Tacoma where it bends sharply north again to reach Seattle. The Ship Canal Bridge carries it over Portage Bay in Seattle. The freeway makes its way out of the Seattle/Tacoma/Everett metro area, crosses the floodplains of three rivers, through the Skagit Valley and the Mount Vernon-Anacortes Metropolitan Area to the northern city of Bellingham to arrive at the Peace Arch Canadian border crossing between Blaine, Washington, and Surrey, British Columbia. Highway 99 continues northwesterly from the border into Vancouver, BC.

History

An extensive section of this highway (over 600 miles or 965 km), from approximately Stockton, California, to Portland, Oregon, follows very closely the track of the Siskiyou Trail.^[3] The Siskiyou Trail was based on an ancient network of Native American footpaths connecting the Pacific Northwest with California's Central Valley. By the 1820s, trappers from the Hudson's Bay Company were the first non-Native Americans to use the route of today's I-5 to move between today's Washington State and California. During the second half of the 19th century, mule trains, stagecoaches, and the Central Pacific railroad also followed the route of the Siskiyou Trail.^[3] By the early 20th Century, pioneering automobile roads were built along the path of the Siskiyou Trail, notably the Pacific Highway. The Pacific Highway ran from British Columbia to San Diego, California, and was the immediate predecessor of much of U.S. Highway 99. The route of Highway 99 was in turn used as a basis for much of the route of today's I-5.

In 1988, smoke from nearby field burning caused a 23 car pileup near Albany, Oregon, leading to 7 deaths and 37 injuries. This accident resulted in more regulation of field burning.^[4]

October 12, 2007 tunnel fire

Main article: Newhall Pass interchange

Around 11 PM Pacific on October 12, 2007, two trucks collided in the truck tunnel near the interchange of Interstate 5 and California State Route 14. A resulting fire started, soon encompassing the entire tunnel and fifteen trucks that were in the tunnel at the time.

Major intersections

Interstate 5 and Interstate 90 meeting in Seattle, Washington.

• Interstate 805 (bypass) in south San Diego, California
• Interstate 15 in San Diego, California (future; this freeway is currently signed as California 15)
• Interstate 8 in San Diego, California
• Interstate 805 (bypass) in north San Diego, California
• Interstate 405 (bypass) at the El Toro Y in Irvine, California
• Interstate 605 in Santa Fe Springs, California
• Interstate 710 southeast of downtown Los Angeles, California
• Interstate 10 at the East Los Angeles Interchange complex, east of downtown Los Angeles, California
• Interstate 405 (bypass) in Sylmar, California
• Interstate 210 in Sylmar, California
• Interstate 580 in Tracy, California
• Interstate 205 in Tracy, California
• Interstate 305 in Sacramento, California (hidden, known as Business Loop 80.)
• Interstate 80 in Sacramento, California
• Interstate 505 in Dunnigan, California
• Interstate 105 in Eugene, Oregon
• Interstate 205 (bypass) in Tualatin, Oregon (southern junction)
• Interstate 405 (bypass) in Portland, Oregon (southern junction)
• Interstate 84 in Portland, Oregon
• Interstate 405 (bypass) in Portland, Oregon (northern junction)
• Interstate 205 (bypass) in Salmon Creek, Washington (northern junction)
• Interstate 705 in Tacoma, Washington
• Interstate 405 (bypass) in Tukwila, Washington (southern junction)
• Interstate 90 in Seattle, Washington
• Interstate 405 (bypass) in Lynnwood, Washington (northern junction)

Auxiliary routes

• San Diego, California - I-805
• San Diego, California - I-905 (future)
• Los Angeles, California - I-105
• Los Angeles, California - I-605
• Los Angeles and Orange County, California - I-405
• Tracy, California - I-205
• Sacramento, California - I-305 (unsigned)
• Zamora, California - I-505
• Eugene, Oregon - I-105
• Portland, Oregon - I-405
• Tacoma, Washington - I-705
• Seattle, Washington - I-405

I-5 will have a complete set of auxiliary routes (105, 205, 305...805, 905), with the completion of Interstate 905 in San Diego. Currently, I-80 and I-90 are the only two interstates to have complete sets of auxiliary routes.

See also

• Randall Woodfield, the "I-5 killer"

References

Main Interstate Highways (multiples of 5 in pink)
4	5	8	10	12	15	16	17	19	20	22	24	25	26	27	29	30
35	37	39	40	43	44	45	49	55	57	59	64	65	66	68	69
70	71	72	73	74	75	76 (W)		76 (E)		77	78	79	80	81	82
83	84 (W)		84 (E)		85	86 (W)		86 (E)		87	88 (W)		88 (E)		89	90
91	93	94	95	96	97	99	(238)		H-1		H-2		H-3
Unsigned			A-1		A-2		A-3		A-4		PRI-1		PRI-2		PRI-3
Lists		Primary			Main - Intrastate - Suffixed - Future - Gaps
		Auxiliary			Main - Future - Unsigned
		Other			Standards - Business - Bypassed

Donate to Wikimedia