What I see with the green box they put near my house is that we don't generally have no right on red intersections, so drivers don't expect one. Many drivers have never noticed the sign that was put up and they don't know what the green box means, so they continue to make rights on red. Cyclists on the other hand more often know how the green box is supposed to work and are expecting that drivers will follow the rules… Fortunately it's on a moderately steep up hill section of street, so cyclists are not going so fast they cannot react to someone who turns across the box illegally. As far as I know only a few were put in as an experiment here, and while they haven't to my knowledge been removed, I don't think the program continued. The city is still using green pavement markings to indicate certain areas where bike lanes merge into regular traffic and some sections where regular traffic must cross bike lanes. I don't know if those make any difference or not to remind motorists to check and cyclists to prepare or if they suffer from the same problem of making it the other guy's problem. The green paint doesn't look gritty or non-slip, so it gives me the heebie jeebies to ride on if it's wet, but I don't think it's overly slippery - I do try to avoid it when possible though...