What state has the least traffic lights? The most?

[Roadgeekteen]

For least, I would guess Alaska, for most, I would guess California.

[JayhawkCO]

I think I'd guess Wyoming has less than Alaska.  Alaska at least has Anchorage for a big city.  Wyoming might only have 10-15 total cities with stoplights and no city is larger than 60K people.

Chris

[Roadgeekteen]

I think I'd guess Wyoming has less than Alaska.  Alaska at least has Anchorage for a big city.  Wyoming might only have 10-15 total cities with stoplights and no city is larger than 60K people.

Chris

Yes, It might be a direct correlation with population. Although I do wonder if the correlation breaks at some point.

[SkyPesos]

What would you count as a traffic light? Each signal head, which can count as much as 16+ traffic lights for a busy 4 lane intersection? Traffic signals facing one direction (so a 4 way intersection would count as 4 signals)? A signals set installation for an intersection?

[Roadgeekteen]

What would you count as a traffic light? Each signal head? Traffic signals facing one direction (so a 4 way intersection would count as 4 signals)? A signals set installation for an intersection?

Didn't think about that... would that make a difference?

[JayhawkCO]

I think I'd guess Wyoming has less than Alaska.  Alaska at least has Anchorage for a big city.  Wyoming might only have 10-15 total cities with stoplights and no city is larger than 60K people.

Chris

Yes, It might be a direct correlation with population. Although I do wonder if the correlation breaks at some point.

I'm sure it does.  A similarly populated state with more area would have less stoplights than a denser state. (Happy 1000th post to me.)

Chris

[SkyPesos]

What would you count as a traffic light? Each signal head? Traffic signals facing one direction (so a 4 way intersection would count as 4 signals)? A signals set installation for an intersection?

Didn't think about that... would that make a difference?

Some states are keen on installing a traffic signal per lane. California frequently only use one overhead left turn signal for 2 left turn lanes. And some states install side signals on the mast arm supports more than others.

[webny99]

Maybe we could just count signalized intersections.

[ran4sh]

What would you count as a traffic light? Each signal head? Traffic signals facing one direction (so a 4 way intersection would count as 4 signals)? A signals set installation for an intersection?

Didn't think about that... would that make a difference?

In addition to the above post about different state practices, there's also the fact that older states were surveyed differently than newer states. Most states with the PLSS survey system will have mostly 4-way intersections because of the grid created by PLSS. But other states will have more 3-way and more different types of intersections.

[Caps81943]

While I believe California likely has the most and Alaska and Wyoming the least, another interesting question is which states are the most stoplight-heavy (ie have not very busy intersections with signals) and which are the most conservative (many busy intersections without signals).

In terms of most "free" (liberal*), I nominate Virginia, Texas, Kansas, or California.

In terms of most restrictive (conservative*), I nominate Wisconsin or Nevada.

[roadman65]

I would say Wyoming with its low population.  Most, it would be between CA, NY, and FL.

[JoePCool14]

Illinois is another state that's pretty liberal with installing traffic lights. Think to stretches where there are lots of commercial driveways, where more lights are installed on busy roads such as US-12 and other state-maintained arterials. It definitely makes some of these streets a slog to travel on at times.

[roadman65]

Probably a thread should be created to most traffic lights per square mile. New York City's metro and the five boroughs alone would win. Southern California and Houston area in TX would come close as well to greater NY.

[roadman65]

What would you count as a traffic light? Each signal head, which can count as much as 16+ traffic lights for a busy 4 lane intersection? Traffic signals facing one direction (so a 4 way intersection would count as 4 signals)? A signals set installation for an intersection?

Here is what google says about California.
The state has an estimated 40,000 intersections with 1.8 million traffic lamps. (That's counting all red, amber, and green lamps, as well as the walk and don't walk signs, the "walking person"  and "hand"  symbols, and directional arrows.)

[EpicRoadways]

Illinois is another state that's pretty liberal with installing traffic lights. Think to stretches where there are lots of commercial driveways, where more lights are installed on busy roads such as US-12 and other state-maintained arterials. It definitely makes some of these streets a slog to travel on at times.

It seems like compared to their other midwestern neighbors, Illinois has largely avoided newer, more "innovative" intersection designs like roundabouts and RCI's, instead opting for a traditional signalized intersection. I wonder why that is. Cost?

[andrepoiy]

Meanwhile most Ontario only have 2 heads per direction, 3 if it's a larger intersection, and only more if it's a very complex intersection

[JoePCool14]

Illinois is another state that's pretty liberal with installing traffic lights. Think to stretches where there are lots of commercial driveways, where more lights are installed on busy roads such as US-12 and other state-maintained arterials. It definitely makes some of these streets a slog to travel on at times.

It seems like compared to their other midwestern neighbors, Illinois has largely avoided newer, more "innovative" intersection designs like roundabouts and RCI's, instead opting for a traditional signalized intersection. I wonder why that is. Cost?

Absolutely. That's one of the biggest reasons I hate living in Illinois as a roadgeek. It's also annoying just to drive, because every interchange is an inefficient cloverleaf, every intersection is an inefficient traffic light. There's just no interesting roads, everything is just a big 4-, 5-, or 6-lane road with traffic lights spammed everywhere. And when we do have something a bit different like Palatine Road, it's only "meh". Stuff doesn't get improved because of cost, and because IDOT as an agency just doesn't take an interest in innovation. Dramatically different compared to WisDOT or even MDOT.

[roadman65]

Meanwhile most Ontario only have 2 heads per direction, 3 if it's a larger intersection, and only more if it's a very complex intersection

New York City imitates Ontario with one on the left and the other on the right instead of one per lane. NJ too mostly, but NJ has switched slowly to one per lane per MUTCD.

[andrepoiy]

I get why having one per lane is nice, but as a driver, I always felt 2 or 3 Ontario-style signals were adequate. Even in areas with lots of truck traffic, I could still generally see at least one signal.

[SkyPesos]

Sometimes, I think 1 per lane is excessive. I like what California does, with 1 left turn for 2 lanes, or 2 straight for 3 lanes. This can also mean shorter mast arms in some situations, which I like for reducing clutter. I also like what Missouri sometimes does, with the mast arm vertical beam placed in the median instead of the side, and the left turn signal on that beam, or the left side of it.