To actually offer the OP some assistance
, I got exactly the same ticket once (at 1:30 AM by Harbour City) - the street was completely empty and I parked in a random spot, and didn't notice the blue sign in the dark because it was high up. I was some kind of pissed to get a ticket, considering every other parking spot on the street was empty. The City knocked it down to $30 for me when I phoned and whined to the parking prosecutor.