In the early 1990's, I was driving for Conway Western Express, with a regular 2 - night run from Irvine to the CWX terminal @ 50 Quint St. in San Francisco. Even at that time it was Loads North -- Empties South or East virtually every trip. All of the heavy industry ( steel fabrication & ship repair ), and most of the light industry had fled the higher taxes, wages, & small spaces of The City for larger, cheaper locations in East Bay & San Jose. This left San Francisco as largely a residential consuming area. And once again the industry, especially warehousing, has moved to the San Jouquin Valley towns and yes Nevada. With the Reno / Sparks area only a 4 to 5 hour drive ( in good weather ) via Interstate 80 & Donner Pass, and with Nevada being very business friendly as noted by others, J I T shipping is do-able quite easily AND cheaply.