Archive for the Roads tag


Traffic Lights and Intersections

Uncategorized No Comment

Hourglass Traffic Light

traffic-hourglassCool, right? Useful? I’m not really sure. The current traffic light, while old, might have gotten it perfectly simple.

Some thoughts:

  • As the green fills up in the bottom of the hourglass. Approaching, will it be clear that it’s empty? Meaning, a large green blob, is a large green blob if you are moving quickly.
  • The yellow countdown timer is useful.
  • Is there a point where there isn’t enough lit up that it would be impossible to see in the fog?
  • The most useful condition is to know that red is almost over. Although that may encourage timing the light and flying off the line.


Flashing left turn arrow
The previous link reminded me of a light in Michigan that I shared with my friends a while back (I have a thing for traffic lights apparently). This light adds a blinking yellow that indicates a left turn is allowed, but you should yield to other traffic. I didn’t like it when I first read about it. I can see the value in a light that sometimes allows left turns on green. During non-rush hours it’s such a pain to hit a left turn only light with no traffic on the road. However, I’m still not sure this is the way to do it. It seems that the blinking yellow would be easily confused with the solid yellow. So you’d either try and make the turn without yielding or stop and wait until you realized it was blinking. I’d have to see some to know for sure, but I don’t expect to be in Michigan any time soon.

Diverging Diamond Intersection
Slightly still on topic. I’ve had this link saved for a while. Take a look at the video, because just looking at a picture it’s almost impossible to figure out how it works. Even with the video, it takes a little bit of effort.

It actually makes a lot of sense. It’s probably a little complicated for people to accept right away and start building them all over. The concept has it’s own homepage and lists quite a few existing ones. None close to me, but maybe I’d go out of my way the next time I’m in Maryland.

Driverless Intersections
Of course these are all meaningless when every car on the road is driverless. I tweeted this one back in February.

Imagine the future terror of going through one of these intersections. Would you ever get used to it? I’m pretty sure everyone who grew up driving themselves would be terrified forever while a generation of driverless kids would just cruise right through with no worries.