the route used to be the main highway along the west coast, but now most people use the interstate 5 to go along the coast. the us 101 used to go south to san diego, but the part of the us 101 between here and los angeles was totally replaced by the i-5 in the 1960s. when it first opened, the us 101 used small roads that had already been built. in 1933, a new highway with bridges and ramps was built so it was faster for people to use.