Interstate 5

Interstate 5 (I-5) is a United States interstate highway that starts at the border with Mexico in San Ysidro, California and runs 1381 miles (2223 km) north through the states of California, Oregon and Washington to the border with Canada in Blaine, Washington. It serves as an important north-south transportation corridor along the U.S west coast connecting the major cities of San Diego, Los Angeles, Portland, and Seattle; the three state capitals of California (Sacramento), Oregon (Salem) and Washington (Olympia); and two additional major cities in neighboring countries (Tijuana & Vancouver) just over the international borders.

Interstate 5 (I-5) replaces the former U.S. Highway 99 (Pacific Hwy Auto Trail from before 1926) between Blaine, Washington and Los Angeles, California, and the old US Route 101 from Los Angeles to San Diego, California as the main north-south route along the west coast. The old U.S. Highway 99 then continued east along the present Interstate 10 from Los Angeles to Indio CA. From Indio U.S. Highway 99 turns south towards the Mexican border in Calexico, on the present day CA-86, along the western shores of the Salton Sea; and from Brawley to Calexico on CA-111. Prior to 1926, the old Pacific Highway Auto Trail went from Davis, California, along Interstate 80 (formerly US Hwy 40) into San Francisco where it went south towards San Diego along US Highway 101.

After decommissioning in the 1960s segments of the old US Highway 99 have been re-numbered to State Route 99 (SR-99) in Washington, Oregon and California while other sections have been re-assigned different state highway numbers in all three states. Others have been decommissioned altogether as a U.S. and state highway (not numbered) but are still remembered by being named "Pacific Highway" (in OR & WA); "Golden State", "County Rd 99", "Old Highway 101" (in CA); "Old Highway 99" or by a different name (in all three states). The old Highway 99/101 can serve as an alternate scenic drive alongside the present I-5 corridor in rural areas while passing through urban areas (or in small towns) as local surface streets. It is accessible from I-5 through multiple exits in all three states. Because of its continuity and its close proximity to the I-5 corridor, in most places, the old Highway 99/101 can serve as an alternate route around a traffic jam on I-5 if needed. There are other sections of the old Highway 99 that are decommissioned as a road for vehicle travel and are used primarily as walking and bicycling trails.

There are no toll segments on the "Freeway". Plans are underway to upgrade the Interstate Bridge (I-5) and the Glenn Jackson Bridge (I-205), over the Columbia River, between Oregon and Washington. Therefore, tolls will be collected to cross these bridges between the two states to compensate the cost of the upgrades.

You'll obviously need a vehicle, but there is nothing really necessary for the route unless you want to eat your own food or you're coming from another country, in which case you might need passports, for example, to get in. Services are generally available and are closer together along I-5.

Traffic on I-5 usually goes on mostly uninterrupted all year round but during winters the sections of I-5 through the Siskiyous between Medford, Oregon and Weed (or even Redding), California can be interrupted prompting the closure of I-5 through the Siskiyous in Southern Oregon and Northern California. This may even prompt authorities to require chains and slower driving or closing the highway in one or both directions. In winter weather it is not recommended for travelers use secondary roads, to get around the closed highway, as they are not usually plowed or sanded. Therefore travelers should plan on using the coastal highway on US 101 before reaching the Siskiyous via CA-36 from Red Bluff to Fortuna or from further south and on US Hwy 199 from Grants Pass to Crescent City or further north. Check the weather and traffic reports before taking alternate routes. Occasionally, snow forces the closure of I-5 over the Grapevine between L.A. and points north, or forces use of snow tires.

During blizzards, enough snow to get you stuck can fall in very little time. Visibility may also be restricted by falling or blowing snow or by condensation or ice on vehicle windows.

Cold weather is hard work for the car. A weak battery, ice on electrical parts or in fuel, frozen diesel, or a frozen cooling system may cause your car to break down. If you get stuck, you may be at risk for frostbite or hypothermia; see cold weather, snow safety and ice safety for discussion.

Interstate 5 begins/ends at the US/Mexican border crossing in San Ysidro at 15 mi (24 km) south of San Diego. Continuing south the freeway splits up with the right two lanes west towards Las Playas of Tijuana on via Internacional and the left two lanes going straight ahead (south) into Zona Rio as Av Via Rapida. The highway continues as Mexico Federal Hwy 1/D along the Pacific Coast towards Ensenada from Las Playas in Tijuana. In the north, I-5 begins/ends at the US/Canadian border crossing at Peach Arch Park in Blaine, Washington. From the border crossing, the freeway continues the next 25 mi (40 km) north to the Oak Street Bridge, over the Fraser River as BC-Hwy 99 where the freeway ends at. From the bridge, BC-Hwy 99 continues towards Vancouver as Granville St through the South Vancouver neighborhood.

Interstate 5 intersects other major US interstate highways diverging to/from different directions such as Interstate 15 and Interstate 8 in San Diego; Interstate 10 in Los Angeles; Interstate 80 in Sacramento; Interstate 84 in Portland; Interstate 90 in Seattle and various three digit interstates (serving as local auxiliary highways), state and U.S highways where travelers can enter and leave I-5.

The Interstate 5 corridor can be accessed by plane through San Diego, Santa Ana, Burbank, Sacramento, Medford, Portland, Seattle, Everett and Bellingham with airports next to or near the freeway. In other cities, such as Los Angeles and Long Beach the airport can be further away (20-40 mi/32-64 km) from the I-5 corridor on another highway. From outside the U.S. the I-5 corridor is also accessed from Vancouver International Airport and Tijuana's General Abelardo L. Rodríguez International Airport.

Mile markers are statewide mileposts, starting with "0" at the south border of each state which increases as you go north and then starts over at "0" when crossing the state line into the next state. Therefore, when going south the numbers on the mileposts will decrease and then start over at the highest number (276 in Washington, 308 in Oregon & 796 in California) when crossing a state line. The exit numbers correspond with the mileposts so some numbers may be skipped if the exits are further apart from one to the next. Other exits that are next to each other or "2 in 1" may have the same exit number followed by an "A", "B" or even a "C" such as "Exit #46A" to get on Oak St, "Exit #46B" to get on US 1 and so forth.

The maximum speed limit is 70 mph (112 km/h) for cars on rural stretches and 65 mph (104 km/h) in urban areas or lower if posted otherwise. Speed limit for large trucks is 55 mph (88 km/h) in both rural and urban areas.

Several segments of Interstate 5 in California directly replaced U.S. Route 99, which is now decommissioned. For more on U.S. Route 99, see Interstate 5/Alternatives#Highway 99.

When on the road, most of the journey is straightforward freeway driving. If it is winter, it is wise to check the weather conditions at the Siskiyou pass, between Redding and Grants Pass, before crossing the border from California into Oregon. Snowy conditions are not uncommon, and officials usually close the road if things become too dangerous. A closure can be waited out in the Shasta or Redding area on the California side, or Ashland and Medford on the Oregon side. It is also possible to detour along the coast via US Hwy 199 from Grants Pass to Crescent City or from further north.

Whistler ← Vancouver ← becomes ← (Peace Arch Park) ←	N  S	→ Ferndale → Bellingham → Seattle
Los Angeles ← San Diego ← Chula Vista ←	N  S	→ (San Ysidro) → Becomes → Tijuana → Ensenada

• Alaska Marine Highway System (AMHS) is a network of ferry lines connecting destinations along the southeastern coast of Alaska and going all the way down to Bellingham, Washington. It provides a connection to many island and island-like communities, separated by fjords, including the Alaskan state capital Juneau which is accessible only by boat or plane despite being located on the mainland. The AMHS is also an alternative to the long drive through Canada for surface travel between the lower 48 states and Alaska, and can be a more affordable (if decidedly less luxurious) way to witness some of the same rugged coastal scenery that Alaskan cruises take in.
• Interstate 10 serves as a continuation of the old Hwy 99 from downtown Los Angeles towards Indio through San Gabriel Valley, San Bernardino, Joshua Tree, Palm Springs and Palm Desert. From Indio the old Hwy 99 continues south on CA-Hwy 86, along the western shores of the Salton Sea, to its southern terminus in Calexico via CA-Hwy 111 from Brawley through El Centro. I-10 can also be part of the Pan American journey from the I-5 corridor in Los Angeles to I-35 in San Antonio where travelers can continue south into Mexico.
• Route 66 (aka Old US 66) was a highway that extended from Chicago to Los Angeles. It crossed much of the American Midwest, Great Plains, and Southwest. Although Highway 66 is no longer commissioned as a US Highway, it represents a multitude of ideas: freedom, migration West, and the loneliness of the American heartland. More than four-fifths of it remain drivable (though not always well-marked) as a collection of state highways and local roads. Radiator Springs is a fictional village on Route 66, depicted in the 2006 Pixar animated film, Cars with real places along the US Route 66 as the backdrop. It intersects Interstate 5/old Hwy 99 at SR-110 (towards "Pasadena") in Los Angeles.
• Pan American (PanAm) Highway In the U.S. all interstate highways make up the 'Pan-American' highway which spans from the northern coast of Alaska to the Darien Gap in Panama. In the Lower 48 Interstate 5 is closest to the southern terminus of the Alaska Highway in Dawson Creek, BC. Travelers, traveling from the Alaska Highway can travel on the Stewart-Cassiar Highway, through British Columbia, to reach the Lower 48 in Blaine, WA.
• Vancouver, BC The freeway continues north of the border as BC-Hwy 99 for the next 25 mi (40 km) into Vancouver BC. From north of Vancouver, BC Hwy 99 winds its way along the shores of Howe Sound, through Garibaldi Provincial Park, Whistler, to its northern terminus at BC Hwy 97 in Cache Creek (337 km north of Vancouver):

• The Sea to Sky region (north of Vancouver) stretches from the North Shore up the east side of Howe Sound to Squamish, the gateway to British Columbia's magnificent alpine country of forests, lakes, and year round world class outdoor activities. The Sea-to-Sky Highway (Highway 99), which gives the region its name, clings to the mountainsides, letting you drive from Vancouver to Whistler, one of North America's top ski resorts, in two hours.

• Tijuana, BCN. Once south of the Mexican inspection station the road continues west along the (Mexican side of) the border to Las Playas barrio and then along the coast as Mex Hwy 1D as a toll "freeway" while Hwy 1 straddles alongside as a 2 lane road to Ensenada(via Rosarito). Mex Hwy 1 serves as the main north-south road along the Baja California peninsula to its southern terminus in ]] San Jose del Cabo (1654 km south of Tijuana).
• Mexicali (also known informally as "Chicali") is the capital of the state of Baja California in Mexico, directly across the border from Calexico, California where the old US Hwy 99 (CA Hwy 111) ends/begins at. Its proximity to the United States has made it a very popular tourist destination, especially for day-trippers. Growing violence has curtailed that traffic, although Mexicali remains safer than other large border cities like Tijuana and Ciudad Juárez.