Californians were among the first in the world to build a lifestyle around the automobile. In the early 20th century, mass-produced cars became affordable for almost everyone. In 1907 there were just 300 autos registered in the state. By 1920, more than 14,000 cars traveled state roads. Public and private interests raced to be the first to connect Humboldt County to San Francisco. In 1914 the Northwest Pacific Railroad celebrated the completion of its line with a golden spike ceremony. Construction of Highway 101 took much longer. State funding was spotty, and graveling and paving the new "all year" highways was slowed by severe weather and difficult terrain. Road engineers had to travel by foot or packhorse along steep slopes. Highway 101 was not completed until 1922.