So cool! I lived in Delft last year (exchange at TU Delft), and I remember the automatic bollards! Your speculation was correct about the picture - as Bouke already pointed out, "Bij groen, een auto" means one care per green light. And you can see by the videos posted here that they're serious! To address mixbyhand's comments, the bollards in Delft are only used to keep people out of the most pedestrianized part of the city; the very centre of the old city. Only delivery trucks, or people who live in the centre, get transponders, I believe. Anyone else can go through, if they are on foot or bike (which, believe me, is almost everyone anyways). Delft is just not a city that you would drive in, unless you are driving out into the country.