Hiawatha Traffic Signals

[Realstreets]

What the hell is up with the timing of the traffic lights. The east-west signals stay green way too long, with no cars coming. I know the train interrupts the signaling but I've notice that Hiawatha will get a green light after the gates go down but once the gates go up, 20 seconds later, the east-west bounds traffic will get a green. I read that the traffic signals were adjusted late last year. Maybe some knows something I don't.

[talindsay]

That's sort of like saying, "kids these days with their loud rock and roll music" - we've all been complaining about this since the street was rebuilt as a practice-freeway back in 2001, especially since the light rail went in.

But I'm curious, is this a newly-noticed issue for you? Because in my experience everything got MUCH better with the most recent round of timing upgrades earlier this year. Until this year the train's signal preemption would always reset the lights to the beginning of their cycle, which could result in some of the late-cycle changes not coming around for a pathologically long time during heavy use periods (for example, the left from southbound Hiawatha to eastbound 26th) - so much so that I'd stopped going that way whenever possible. The new signal controls resume where they were left off after the train preempts the signal, so it's not the problem it was before, and I've gone back to using Hiawatha for local trips again. It can still be slow at times, but it's never pathological like it used to be.

[Realstreets]

I'm a new resident so I only have a couple months experience with the Hiawatha lights. However, I've sat at 32nd for about a minute after the cars have proceed through the intersection waiting for the light to change. Maybe the sensors on east-west streets are malfunctioning.

Also, any idea why flashing left turn arrows aren't used at these intersections? Visibility?

[talindsay]

Yeah, waiting "about a minute" after the road is clear is a huge improvement - MnDOT has been fighting to get the signals along Hiawatha even close to reasonable for a decade now, and until fairly recently there were places where you could get stuck for ten minutes - I kid you not, I once sat for ten minutes trying to turn left onto 26th.

Be aware that they're continuing to work on it.

Regarding flashing lefts, they're very new here although they are now the standard; eventually we'll probably have them along Hiawatha, but there's a lot of protected lefts right now.

[Scott Wood]

Why would a flashing left be used where a green ball is not currently used?

[Wedgeguy]

Why would a flashing left be used where a green ball is not currently used?

Because if there is a flashing yellow arrow that is for a turn lane. Most turn lanes, are a green or red arrow which does not allow you to make a left turn unless it is green arrow. A flashing yellow arrow is yield to oncoming traffic and when clear make your turn. Would be similar to a regular traffic signal, where you have to yield to on coming traffic before you can make your turn.

[FISHMANPET]

A flashing yellow arrow is exactly the same as a green light, it just reminds people that they can turn. But in my experience it's a problem that doesn't exist, people know they can make left turns on green.

[Wedgeguy]

A flashing yellow arrow is exactly the same as a green light, it just reminds people that they can turn. But in my experience it's a problem that doesn't exist, people know they can make left turns on green.

But the flashing yellow arrow are generally at areas where there is a turn lane , which a majority of the time is a Green arrow is go and red arrow is stop.. You don't make a turn on a red arrow. The flashing yellow allows you to make a turn if there is no oncoming traffic instead of having to wait until the next green arrow cycle comes around.

[FISHMANPET]

You can also just turn off the arrow and have just the green light. I've seen that all over, including at Cedar & Franklin, and it works just fine.

Sent from my Nexus 4 using Tapatalk 4

[mulad]

Blinking yellow arrows can get by with signal heads that only have 3 elements (arrows of all three colors). Typical semi-protected lefts will have 5 elements instead (three solid colors plus yellow and green arrows).

One good thing about blinking yellows its that they can be added with less effort to existing installations which only have the 3-element head.

[mattaudio]

Thanks! I was just going to try and explain that and you did it so much better Mike!

If a "protected phase" right has a red arrow (3 lights) then you cannot turn while the other phase (non-arrow) has a green. Unless the yellow is flashing.

Yellow flashing lights give more options with fewer lights. For example, during peak periods it might not make sense to have the yellow flash. With a traditional 5 light "semi-protected" left, there's no way to separate the semi-protected phase... it is tied in with the same green light for vehicles going straight.

Finally, and this may be a topic for the roadgeek thread... I am NOT a fan of "protected rights" at normal suburban intersections. They make stroads even more pedestrian hostile.

[FISHMANPET]

Do people really have problems taking left turns on green though? Maybe I'm overestimating the competency of an average driver, but I don't think drivers need to be encouraged to use their right of way, if anything it's the opposite, they'll do things when they shouldn't. I don't think drivers need to be encouraged to do the things they're allowed, because all drivers are assholes anyway.

Even I become an asshole behind the wheel.

[mulad]

Yeah, if you have a solid green disc at a left turn, it should always be treated as a yield indication. I don't see any significant advantage to changing existing 5-piece signal heads other than consistency. For new or completely replaced signals, I imagine the 3-piece units are slightly cheaper -- probably not much of the overall system cost (I suppose Mdcastle may know).

[Wedgeguy]

The confusion is that there are turn lanes where there are separate arrow signals where green and red arrows. There are turn lanes here the thru traffic and turn lanes are combined. The flashing yellow arrows are for the turn lanes that would have normally been a green or red only.

[FISHMANPET]

It just sounds like a solution in search of a problem. In my experience drivers take more right of way than they're allowed, they don't need to be encouraged to make those left turns, because they're already doing it.

And besides, it's pretty simple:
Green left turn arrow means you can go and there's no oncoming traffic
Red left turn arrow means don't turn
Solid green disk means you can turn as long as you yield to oncoming traffic.

All 3 of those can exist in the same cycle if they need to.

[Wedgeguy]

Excuse me. Green arrow means that you have the right of way against the crossing traffic as they have a red light whether there is traffic or not. When the arrow turn yellow, like any yellow means that you must yield to cross traffic which now will have the right of way. Red arrow means that you can't make your turn unless you want to break the law. I don't know of any intersection where the opposite traffic can go thru when the turn lane in the opposite direction has the green. Go to Lyndale and Franklin to see where a standard signal is used. Go to Minnetonka BLVD and HWY 100 to see where the yellow flashing arrows work and think about how different both of these intersections are. There is a reason why not all Arrows have the flashing yellows to allow turns.

[FISHMANPET]

I mean't "no oncoming traffic" as in there is no oncoming traffic entering the intersection because oncoming traffic has a red light.

And again, I don't see the problem a yellow turn arrow is supposed to solve. Drivers know they can turn left on a solid green as long as they yield to oncoming traffic, so why do we need a more expensive signal head to tell drivers something they already know?

[MNdible]

Does somebody have a dead horse gif that can be inserted now?

[mister.shoes]

...so why do we need a more expensive signal head to tell drivers something they already know?

It's the other way around, no?

solid red + solid yellow + solid green + yellow arrow + green arrow = $$$$$
red arrow + yellow arrow (that can flash) + green arrow = $$$

There's no way to have a protected left turn on a green arrow AND a yield to oncoming traffic left turn on a solid green ball without using the five light head. Hence, the flashing yellow arrow.

[FISHMANPET]

I mean if you want to pick random combinations of traffic signals sure we can all play that game.

What extra information does a yellow turn signal give that isn't already conveyed in a solid green light? Nothing right? So why put them in anywhere?