Traffic Signals

[Mdcastle]

A few notes on what's going on as far as signals:

ADA upgrades: All new / rebuilt intersections need to be "accessible" This means curb cuts must meet specs and included those metal plates with bumps, beg buttons (custom programed with audible / tactile feedback are mandatory even if there is no vehicle detector in that direction- they have to be parallel and next to the sidewalks, so in practice this means at least one additional pole, sometimes 2, for drunk drivers to knock over), and countdown indicators. Due to costs, Mn/DOT will be evaluating "removing unnecessary crosswalks" rather than pay to retrofit them.

3M optical programmable visibility signal heads are long out of production. Once their patents expired McCain cloned almost an exact copy (the most visible difference being the shape of the lamp doors on the back and round rather than square visors) and 3M chose to exit the business. Minneapolis and the counties had to use McCain for a short while having no other choice, but now use Intelight electronic programmable visibility, which integrate the LEDs with the heads. These can be programed by a worker on the street with a smartphone, rather than a guy in a bucket truck with special black duct tape.

Per the Minnesota MUTCD (the book that tells what signs, signals, road striping, and stuff are allowed or not), 8" signal heads are still allowed for streets 30 mph or less, but in practice Minneapolis and St. Paul were the only agencies that used them extensively, and they now use 12" for all applications.

A green ball over a left turn lane is no longer allowed, It must be a flashing yellow arrow or a green arrow. Right now the Minnesota MUTCD allows a three head with a FYA on the bottom (there are none of these in the field) and doesn't address shared lanes,, the new version will specify a four section head for dedicated lanes, and a 5 light "doghouse" with a bimodal (changes between yellow and green) arrow for shared lanes.

Mn/DOT has switched to galvanized finishes on signal poles. Mn/DOt considers this an acceptable finish and if a city wants it painted they have to pay for it.

If anyone wonders how much energy LED traffic signals save- 8" indications use 69 watt lamps, GE DR4 LEDs use 4.5 green, 5.5 red, and 12.9 yellow.

[MSPtoMKE]

Someone is going to have to explain to me how requiring a button to be pushed to cross the street makes the intersection more ADA accessible, especially in regards to people who are blind.

[ECtransplant]

The new kind of beg buttons have verbal and tactile responses announcing when the pedestrian has the signal to cross.

[Mdcastle]

Also, the locations of the posts and the raised arrows indicate exactly where the crosswalks are (although of course this also be done with a sign)

[Mdcastle]

And the city of Minneapolis has gotten special funding to "upgrade obsolete traffic controllers". So that mean the last of the electro-mechanical controllers (you can tell because of the massive chunk noise the solenoid makes during a color change) will be scrapped.

[David Greene]

And the city of Minneapolis has gotten special funding to "upgrade obsolete traffic controllers". So that mean the last of the electro-mechanical controllers (you can tell because of the massive chunk noise the solenoid makes during a color change) will be scrapped.

*sigh* I love that sound. Another bit of technological history lost to progress.

[mattaudio]

Someone is going to have to explain to me how requiring a button to be pushed to cross the street makes the intersection more ADA accessible, especially in regards to people who are blind.

I'm still wondering the same thing.

[Mdcastle]

My father is married to a blind person and I collect traffic signal equipment so I know quite a bit about the issues.

If you're blind or deaf-blind and approach an intersection, there's no way of a signal communicating whether it's showing walk or don't walk or exactly where the crosswalks are. The audible/vibrating buttons do that. I recall reading on some document that automatically giving a walk whether or not the button was pushed, but I don't see why they couldn't, since you don't have to push the thing for it to vibrate/talk and in fact I've seen a lot that still do give a walk every cycle.

There's a disagreement whether blind people even want us to make major accommodations to them. Some do and some don't. Without the beg buttons they rely on service animals, listening to traffic (and the noise the buttons make can mask this), drivers being careful when they see a white cane; square signal pole bases are also helpful.

[mattaudio]

Thanks for the clarification. I've seen a lot more of these enhancements in cities around the world compared to what we are now getting in the US, including all sidewalks having tactile guideway strips so people with canes can determine the path down the sidewalk.

It seems as though we can really separate these two issues completely, since there are ways to build good signalized intersections for those with disabilities without beg buttons, and there are obviously ways to build bad pedestrian intersections that are ADA compliant. I'd rather see retrofits to enhance accessibility while simultaneously reducing the number of beg buttons.

[Wedgeguy]

I know the cross walks at the Hennepin transit station have an audible saying that you can go for the blind.

[twincitizen]

One thing seems clear: automatic walk signal with green light should be mandatory, as in pressing the beg button should not be a requirement if one wants to cross. At least in areas over a certain population density / walkscore threshold. It pisses me off to no end that the walk signals in Richfield are not automatic, which are all Hennepin County roads naturally. As a Minneapolis resident, I am not accustomed to begging for permission to cross the street.

[mattaudio]

Well then don't come down here by Minnehaha Parkway, where hundreds of bikers a day have to maneuver awkwardly far from the smooth curb cut to press a beg button to cross.

[seanrichardryan]

Are we still framing an entire 'traffic signals are stupid' argument from one poor biker, at one intersection, having to "awkwardly" press a button to change a signal they could just ignore? Just checking.

[mattaudio]

Yep that's absolutely correct. Glad you read the thread carefully.

[Mdcastle]

I'd be fine with automatic walk signals in dense, "walkable" areas since it could probably be done there without degrading performance for cars since the streets are likely to be narrow and there would likely be pedestrians anyway. But out in the outer suburbs I never saw what was wrong with requesting a walk by pushing a button, but infrared sensors are under development anyway so pedestrians can be detected just like cars are.

I do bike across that particular Minnehaha Parkway intersection a lot and do find it annoying. Even more between Calhoun Parkway and Berry Drive.

[mulad]

I come across a lot of intersections where the timing either isn't any different when pedestrian signals come on, or the timing difference is only a few seconds (like 2-5). There's little excuse for those to not have the signals always activate. Now when we're talking about big suburban intersections with double-left-turns and things like that, then there are bigger problems to worry about.

[RailBaronYarr]

http://youtu.be/-vzDDMzq7d0?t=13m

[Nick]

Quick note: Does anyone else see blind people using the bus, etc., and just have their jaw drop? That's amazing. Every time I see a blind person out in the world, crossing major streets, using transit, my mind is completely blown. Makes me feel like I have zero skill at anything.

[twincitizen]

I hope Nick and I aren't perceived to be making light of a disability, but I agree. Try even walking down the sidewalk in a straight line with your eyes closed for like more than 10 seconds...it's impossible. What an incredible adaptation of the remaining senses to be able to function and successfully move about our incredibly hostile-to-pedestrians world.

[mattaudio]

Question - have any visually-impaired Minneapolitans used the thunk of the eletro-mechanical signal controllers to determine a phase change? Maybe we can keep them to help with ADA.