Automatic pedestrian actuation

[Duke87]

So, I had a thought. In the US there are two accepted methods of having a pedestrian signal work - either it comes on every cycle, or it comes on only when someone pushes the button. But, the walk signal isn't necessarily needed every cycle, and if there's a button people often can't be arsed to push it and just cross whenever the street they're walking along gets a green (or cross against the light, if practical).

For motor vehicles it is common practice to skip a signal phase if it's not needed, and this is generally determined via induction loops or via video detection. Both automatic methods - a driver never needs to push a button for a green light.

What I'm curious about is this - has anywhere (doesn't have to be in the US) experimented with having a pedestrian walk signal trigger via a similar automatic method? Perhaps via pressure sensors in the curb cut, via video detection aimed at it, or some other means?

Here's an example of something sort of along these lines. The two bollards on either side of the crosswalk have laser beams going between them. If the beams are broken, it triggers yellow lights around the edge of the pedestrian sign to flash. But this is just a crosswalk, it is not at a traffic signal and there is no walk signal being controlled by it.

[tradephoric]

Here's a link to a study that evaluates microwave and infrared pedestrian sensors in LA, Phoenix, and Rochester NY.   It also includes a literature review of other automatic pedestrian detection systems used in the UK and Sweden.  I didn't read too deep into it and the study was done in 2001 so take it for what it's worth. 

http://nacto.org/docs/usdg/evaluation_of_automated_pedestrian_detection_at_signalized_intersections_hughes.pdf

[riiga]

I don't know of any detectors in the ground that are used to detect pedestrians, but induction loops are used for bikes here quite commonly. There are however a few crosswalks with pedestrian dectection, though they are non-signalized crosswalks and only have sensors that activate flashing lights to warn motorists. Here, the two lights atop the sign flash alternating in amber. Here you can se the detection mechanism, the white sensors.

For those wondering, the law here is to yield to pedestrians in or just about to enter a non-signalized crosswalk if it can be done safely.

[Duke87]

Here's a link to a study that evaluates microwave and infrared pedestrian sensors in LA, Phoenix, and Rochester NY.   It also includes a literature review of other automatic pedestrian detection systems used in the UK and Sweden.  I didn't read too deep into it and the study was done in 2001 so take it for what it's worth. 

http://nacto.org/docs/usdg/evaluation_of_automated_pedestrian_detection_at_signalized_intersections_hughes.pdf

Especially interesting reading about the technical challenges faced in Phoenix. Seems like microwave detection might not be the best way of going about this.

The report points out that these systems are effective, but then says "It remains to be shown whether the benefits of automatic detection outweigh its cost". So there's one obstacle.

[roadfro]

Here's one in California that used* video detection: Bike/Ped trail crossing on SR 89 about 1.5 miles south of SR 28 in Tahoe City (Street View). Although it is just a crossing, and does not include a traffic signal.

The trail switches from one side of SR 89 to the other here. A camera picks up the bike/ped on approach to the crossing. This activates a warning beacon on the advance ped warning sign, as well as flashing LED lines on the warning sign at the crossing (visible in the Street View). This system has been around since at least 2008.


*I said "used" above because, according to a permanent-looking sign in this June 2015 street view image, the automatic warning system is not operational (and the system seems to be on constant flash).

[jakeroot]

Here's one in California that used* video detection: Bike/Ped trail crossing on SR 89 about 1.5 miles south of SR 28 in Tahoe City (Street View). Although it is just a crossing, and does not include a traffic signal.

I wonder if they de-activated it because it was picking up squirrels and stuff? Or it broke?

[mrsman]

So, I had a thought. In the US there are two accepted methods of having a pedestrian signal work - either it comes on every cycle, or it comes on only when someone pushes the button. But, the walk signal isn't necessarily needed every cycle, and if there's a button people often can't be arsed to push it and just cross whenever the street they're walking along gets a green (or cross against the light, if practical).

For motor vehicles it is common practice to skip a signal phase if it's not needed, and this is generally determined via induction loops or via video detection. Both automatic methods - a driver never needs to push a button for a green light.

What I'm curious about is this - has anywhere (doesn't have to be in the US) experimented with having a pedestrian walk signal trigger via a similar automatic method? Perhaps via pressure sensors in the curb cut, via video detection aimed at it, or some other means?

Here's an example of something sort of along these lines. The two bollards on either side of the crosswalk have laser beams going between them. If the beams are broken, it triggers yellow lights around the edge of the pedestrian sign to flash. But this is just a crosswalk, it is not at a traffic signal and there is no walk signal being controlled by it.

Maybe I'm misunterstanding your point, but is the only thing you are changing is the detection method?  It seems like it would be silmilar circuitry and timing involved, with the exception being whether the circuit is closed via push button or whether the circuit is closed by microwave.  It doesn't seem like that much of a change.

Now an intersection that <i> anticipates </i> a pedestrian is another matter.  Imagine a sensor put back 300 feet that notices when a pedestrian is coming and changes for the pedestrian as he approaches the crosswalk, without having to break his stride!  This probablly doesn't exist.

In my view, the induction and the microwave is basically using your body to push the button.