Interstate 5 is 797 miles long and spans the entire West Coast which makes it one of the most traveled north/south highways along the pacific coast.
Beginning in San Diego, California, at the busiest international border crossing, I-5 travels north to Blaine WA. I-5 connects all of the major cities along the coast, including, San Diego, Los Angeles, Sacramento, Portland and Seattle. Due to travel along the seaboard, I5 weather will vary. Watch out for fog and smog on your travels.