Marin County

 "Each of us is put here in this time and this place to personally decide the future of humankind. Did you think you were put here for something less?" - Chief Arvol Looking Horse

 Signs placed on U.S. 101 in Marin County.

 "Nothing in life is certain except for death, taxes, and the second law of thermodynamics." - Seth Lloyd

"A genius is a mentally ill person with an audience." - Tim Minchin

 "Do not wait; the time will never be 'just right.' Start where you stand, and work with whatever tools you may have at your command, and better tools will be found as you go along." - Napolean Hill

 "I'll sleep when I'm dead" - Warren Zevon

 Total - 6,700

California

"The shortest answer is doing the thing." - Ernest Hemingway

Signs placed on freeways around California.

"Precisely the least, the softest, lightest, a lizard's rustling, a breath, a breeze, a moment's glance... it is little that makes the best happiness." - Friedrich Nietzsche

"A way of doing something original is by trying something so painstaking that nobody else has ever bothered with it." - Brian Eno

"Progress is man’s indifference to the lessons of history." - Len Deighton

"Experience is something you don't get until just after you need it." - Steven Wright

Total - 6692

Berkeley

 "All we have to decide is what to do with the time that is given us." J.R.R. Tolkien

 Signs placed on Interstate 80 in Berkeley.

"Neutrality is at times a graver sin than belligerence." - Louis D. Brandeis

 "I don't have a girlfriend. But I do know a woman who'd be mad at me for saying that." - Mitch Hedberg

 “One of the penalties of an ecological education is that one lives alone in a world of wounds." - Aldo Leopold

 "It does not matter how slowly you go as long as you do not stop." - Confucious

TOTAL - 6,683

Los Angeles

 "We shouldn't be saying 'Save the planet'; we should be saying: 'Save viable conditions in which people can live.'" - Margaret Atwood

 Signs placed on the 5, 10, 101 an 110 freeways in Los Angeles.

 "I envy paranoids; they actually feel people are paying attention to them." - Susan Sontag

"It's this way:

  being captured is beside the point,
  the point is not to surrender." - Nazim Hikmet

 "Change is the process by which the future invades our lives." - Alvin Toffler

 "Nationalism does nothing but teach you how to hate people that you never met and take pride in accomplishments you had no part in whatsoever." - Doug Stanhope

 The earth laughs in flowers. - Ralph Waldo Emerson

Total - 6,675

Oakland

 "With the growing urgency of climate change, we cannot have it both ways. We cannot shout from the rooftops about the dangers of global warming and then turn around and shout even louder about the 'dangers' of windmills." - David Suzuki

 Signs placed on the 580 and 880 in Oakland, California.

"That's one of the amazing things about life. It's never so bad it can't get worse." - Bill Watterson

 "The only difference between suicide and martyrdom is press coverage." - Chuck Palahniuk

 "Those are my principles and if you don't like them, I have others." - Groucho Marx

 "Religion was invented when the first con man met the first fool." - Mark Twain

 "I'm addicted to placebos." - Steven Wright

Total - 6666