Sand Clock Stoplights? Opinions?

[adventurernumber1]

I saw this on iFunny, and it actually seems like an interesting idea. https://m.flickr.com/#/photos/127322363@N08/15295332960/

What are yalls opinions on this?

[Scott5114]

It's been discussed here before. The MUTCD specifically bars such a signal. It has the problem of causing people to drive more recklessly to beat the light because they know it's about to change. The specific signal design shown makes it impossible for red-green colorblind people to interpret the signal aspect.

[spooky]

I also don't see how this would effectively work on an actuated signal. The green time varies between a min and a max time based on demand. Would the "sand" distribution be constantly changing?

[tradephoric]

I also don't see how this would effectively work on an actuated signal. The green time varies between a min and a max time based on demand. Would the "sand" distribution be constantly changing?

Keep in mind that actuated signals still need a "reference point"  to maintain coordination with surrounding signals.  The main-phase is usually programmed to soak up any unused time from previous phases but the main phase itself won't gap out early (if every phase is allowed to gap out the signal is effectively running isolated).  Therefore a "countdown"  would be effective on the main corridor even if actuated signals are being used (it wouldn't be effective on the side-streets though).