This photo is quite remarkable when you know the context. This is the evening peak hour on L.A.’s Arroyo Seco Parkway on November 27, 1954. You’d think that it was taken at 7pm but in fact it was taken just before 5pm. Why does it look two hours later than it should? Because the smog was so thick that it induced an early dusk. Thank goodness someone decided that Los Angeles needed to clean up its air!

Tony says: “I respectfully question how much of the darkness in this photo is directly attributable to smog. Keep in mind that in November, in Southern California when California is on Pacific Standard Time, sunset is around 5:00 pm. Several sources from an almanac to the National Weather Service confirm this.“

Bob says: “Yes. And visibility was 10 miles in LA. Additionally that date was a Saturday, 2 days after Thanksgiving, so the amount of traffic seems odd. Not that the smog wasn’t bad in those days.”