Is it only on when your down there or is it normally on until you go to bed?

This picture is old! I still had the black Siemens/Eagle on the floor and no Intelight... and the 3M visors were still not painted!! Anyways...to answer your question.. they are only on when I'm downstairs.

How come there are so many variations on protected and yielded left turns? I've only ever seen the bi-color arrows here so I'd be pretty confused if I were to see a flashing yellow arrow or flashing green ball.

Up until recently it was up to the state's individual law what type of left turn signal was used. Some states used a doghouse head, others used a flashing interval, some didnt use any permissive interval. The flashing yellow arrow was developed in the early 2000s and put on the books in 2009 and was federally mandated to make all pocket left turn intersections uniform. States are slowly jumping on the bandwagon since specs say you can use the existing equipment until stock runs out or parts get worn out. Others are just replacing as they get the money to do it.

The common flashing arrow head has four sections. Other types include a 3 section head with bimodal Y/G bottom arrow. Limited and Banned versions of this type of signal include a doghouse version (Red Ball on top, Yellow Arrow and Green Arrow on lower left side, Yellow Ball, and Flashing Yellow Arrow on bottom right side) and a permissive only version (three lights Red Ball, Yellow Arrow, and Flashing Yellow Arrow only)

Hmm. Here we use the four section Red ball-Yellow ball-Green ball-Y/G arrow. In MA they use the doghosue style but with a red ball on top, yellow arrow on top left, green arrow on bottom left, yellow ball on the top right, and a green ball on the bottom right. Are new intersections required to have flashing yellow arrows now? Here we have these signs at our intersections with bi-color arrows.

In PA, we use 5 section doghouse traffic signals. Last summer in Natrona, PA, there were several intersections that had doghouse signals installed replacing the 4 section signals giving motorists a protected left turn.

Did the 4 section signals isntalled have flashing arrows or like the ones here?

No, they had a green arrow on the lower section that would light for 7 seconds.

The states are still allowed to do what they want. Some...like Maryland have opposed using flashing yellow arrows altogether despite the federal law. But a good chunk of the states have started replacing and upgrading to FYA, and theres states that continue to install and use what they have in supply...but the new standard is in the books.

Well, over here in Ontario the most common left turn light is the 4 section head with a bi colour arrow in the fourth section. However we still have some old style green arrow only and flashing green balls left in use too.

Signals here seem to vary by county some place in Ontario flash their green left turn arrows.

Colorado doesn't like to use Doghouses at all, they use the what is called "5 section side by side" which is like a doghouse but instead of red being in the middle it's just the normal traffic signal on the right with three sections and the two arrows on the left beside the normal traffic signal, you have seen pictures.

Nick, have you heard anything like that before? It doesn't seem that common around other places, just extremely common around Colorado..

I hardly ever see any blinking yellows but I do sometimes. I have seen a couple in some places, but they aren't common at all.

Pennsylvania started using doghouses in early 1989, in fact doghouse traffic lights are still installed.

Hmm. I wonder why they changed the standard. It seems to me that either a doghouse style or bi-color arrow is the easiest to understand besides just a normal three section R-Y-G arrow signal head. Do you know of any plans to require all states to change their lights to the new standard?

They changed the standard because every state had its own. This was to uniform everything down the line. Doghouse may have been common in your state and it was pretty common in other places too. We never had doghouse heads in the spec until recently with right turns when yellow arrows were required. Bi-Modal arrows are banned in many states because of the colorblind issue. Michigan is among these. Doghouse heads have an issue called Yellow Trap.

When a signal lags the green arrow in the opposite direction, your signals will show a yellow, while the opposing show green. Drivers anticipate that everyones getting yellow and end up getting tbone. Theres no proper permissive interval. Flashing yellow works better in a lead/lag and other permissive left movements because the yellow flashing arrow never disappears unless its a protected movement OR the signal in both directions is changing to red.

The timetable for flashing yellows depends on how much money the municipalities have, the current supply of equipment, and the upgrading schedules. There are states that have chosen not to follow the federal standard.

I guess Rhode Island is among the states that didn't chose to follow the new standard. I still see the bi-color arrows installed here.

Remember what I said...the standard is written out stating that existing supply can be used until it runs out. That may or may not be the case with Rhode Island I haven't checked that state.