AARoads Forum

National Boards => General Highway Talk => Topic started by: geek11111 on February 22, 2024, 12:57:02 PM

Title: About traffic lights
Post by: geek11111 on February 22, 2024, 12:57:02 PM

[size=78%]Why there's no countdowns for vehicle's traffic lights? It seems that it's banned by law. [/size]


Also, some intersections have a "No turn on red", it could be a round green light, with yellow and red right arrow beside it:
O ->
O ->
O
Title: Re: About traffic lights
Post by: freebrickproductions on February 22, 2024, 04:13:57 PM
Quote from: geek11111 on February 22, 2024, 12:57:02 PM
Also, some intersections have a "No turn on red", it could be a round green light, with yellow and red right arrow beside it:
O ->
O ->
O

Huntsville, AL, actually did something similar recently for a new right on red prohibition on California Street:
Title: Re: About traffic lights
Post by: 1995hoo on February 22, 2024, 04:25:31 PM
Some British traffic lights do something that is slightly the opposite of that for right-turn lanes (bearing in mind they drive on the left). See this traffic light on the B4056 outside the Airbus car park in Filton and notice the second signal head to the right of the green light. That's where the green arrow is. (https://maps.app.goo.gl/Y2VUKYa4fevggWcL8) It functions similarly to a doghouse signal except there's no yellow arrow. Of course, it's also fair to note that the Brits do not allow left turns on red (the equivalent of our right on red), so the "no turn on red" scenario is irrelevant over there.

The thing I really like about British traffic signals, and that I find it extremely annoying not to have in the USA, is the combined red-yellow cycle that briefly comes on just before you get a green light. British drivers know the green is coming on and they go as soon as it's green.
Title: Re: About traffic lights
Post by: NoGoodNamesAvailable on February 24, 2024, 08:29:40 PM
Quote from: 1995hoo on February 22, 2024, 04:25:31 PM
The thing I really like about British traffic signals, and that I find it extremely annoying not to have in the USA, is the combined red-yellow cycle that briefly comes on just before you get a green light. British drivers know the green is coming on and they go as soon as it's green.

I guess the logic is that in the UK most cars are manual transmission whereas in the US it's a tiny percentage. The warning is more useful when you need to switch into first gear quickly.

And knowing American drivers a lot of people would jump the gun and start moving on red-yellow. And probably sue the city when they get t-boned.
Title: Re: About traffic lights
Post by: fwydriver405 on February 25, 2024, 10:22:59 AM
Quote from: freebrickproductions on February 22, 2024, 04:13:57 PM
Quote from: geek11111 on February 22, 2024, 12:57:02 PM
Also, some intersections have a "No turn on red", it could be a round green light, with yellow and red right arrow beside it:
O ->
O ->
O

Huntsville, AL, actually did something similar recently for a new right on red prohibition on California Street:

(clipped)

A few CA locations also have done this, albeit in an inline 4 (https://www.google.com/maps/@34.0462517,-118.2629269,3a,15y,91.46h,92.01t/data=!3m7!1e1!3m5!1s7c96j8uMYwOTiaB45zF48w!2e0!5s20120801T000000!7i13312!8i6656?hl=en&entry=ttu) (Los Angeles) or 5 (https://www.google.com/maps/@37.4004885,-122.058431,3a,75y,265.92h,95.89t/data=!3m6!1e1!3m4!1swpktjZWQZtKMedH5GOfBfA!2e0!7i16384!8i8192?hl=en&entry=ttu) (Mountain View) configuration as shown below:

QuoteO
<- or ->
O
O
<- (Inline 5 only)

https://www.youtube.com/watch?v=QcQuzuaRXa0
Title: Re: About traffic lights
Post by: 1995hoo on February 25, 2024, 12:05:50 PM
Quote from: NoGoodNamesAvailable on February 24, 2024, 08:29:40 PM
Quote from: 1995hoo on February 22, 2024, 04:25:31 PM
The thing I really like about British traffic signals, and that I find it extremely annoying not to have in the USA, is the combined red-yellow cycle that briefly comes on just before you get a green light. British drivers know the green is coming on and they go as soon as it's green.

I guess the logic is that in the UK most cars are manual transmission whereas in the US it's a tiny percentage. The warning is more useful when you need to switch into first gear quickly.

...

I don't know whether that logic holds because I would presume both countries have used these light styles for many years. Slushboxes were a lot less prevalent in the United States 60 and 70 years ago, for example. It might be an argument for not fixing our traffic lights now, perhaps, but otherwise it seems sort of like a post hoc explanation.
Title: Re: About traffic lights
Post by: NoGoodNamesAvailable on February 25, 2024, 12:29:59 PM
Quote from: 1995hoo on February 25, 2024, 12:05:50 PM
Quote from: NoGoodNamesAvailable on February 24, 2024, 08:29:40 PM
Quote from: 1995hoo on February 22, 2024, 04:25:31 PM
The thing I really like about British traffic signals, and that I find it extremely annoying not to have in the USA, is the combined red-yellow cycle that briefly comes on just before you get a green light. British drivers know the green is coming on and they go as soon as it's green.

I guess the logic is that in the UK most cars are manual transmission whereas in the US it's a tiny percentage. The warning is more useful when you need to switch into first gear quickly.

...

I don't know whether that logic holds because I would presume both countries have used these light styles for many years. Slushboxes were a lot less prevalent in the United States 60 and 70 years ago, for example. It might be an argument for not fixing our traffic lights now, perhaps, but otherwise it seems sort of like a post hoc explanation.

Another explanation, the UK uses nearside signals so you usually can't see the other approaches' signals. In the US we use farside signals and 90% of the time you can see when the light for the other road is turning red. Or you can look at the pedestrian countdowns.
Title: Re: About traffic lights
Post by: jeffandnicole on February 25, 2024, 02:34:12 PM
Quote from: geek11111 on February 22, 2024, 12:57:02 PM

[size=78%]Why there's no countdowns for vehicle's traffic lights? It seems that it's banned by law. [/size]

It's banned by federal guidance, which isn't state law.  If the feds suddenly allowed countdown timers, the states would have the option to use countdown timers without needing to overturn existing laws (unless a state does happen to have such a law).

Quote from: geek11111 on February 22, 2024, 12:57:02 PM
Also, some intersections have a "No turn on red", it could be a round green light, with yellow and red right arrow beside it:
O ->
O ->
O

Some states allow right turns on red arrows.  Other states may not allow it, but post a sign making it clear turns aren't permitted.

The green ball is used when there's a change of a confliction, such as pedestrians having permission to cross via a walk signal, or opposing left turning traffic is permitted to make a left turn.
Title: Re: About traffic lights
Post by: mrsman on March 01, 2024, 11:39:52 AM
Quote from: fwydriver405 on February 25, 2024, 10:22:59 AM
Quote from: freebrickproductions on February 22, 2024, 04:13:57 PM
Quote from: geek11111 on February 22, 2024, 12:57:02 PM
Also, some intersections have a "No turn on red", it could be a round green light, with yellow and red right arrow beside it:
O ->
O ->
O

Huntsville, AL, actually did something similar recently for a new right on red prohibition on California Street:

(clipped)

A few CA locations also have done this, albeit in an inline 4 (https://www.google.com/maps/@34.0462517,-118.2629269,3a,15y,91.46h,92.01t/data=!3m7!1e1!3m5!1s7c96j8uMYwOTiaB45zF48w!2e0!5s20120801T000000!7i13312!8i6656?hl=en&entry=ttu) (Los Angeles) or 5 (https://www.google.com/maps/@37.4004885,-122.058431,3a,75y,265.92h,95.89t/data=!3m6!1e1!3m4!1swpktjZWQZtKMedH5GOfBfA!2e0!7i16384!8i8192?hl=en&entry=ttu) (Mountain View) configuration as shown below:

QuoteO
<- or ->
O
O
<- (Inline 5 only)

https://www.youtube.com/watch?v=QcQuzuaRXa0

The Los Angeles example (since changed since now there is an exclusive phase) was meant to incorporate a special type of leading pedestrian interval.  When walk signal is on, straight ahead can go right away, but left turners must wait a few seconds (until the red arrow goes away) before making their turn while yielding to pedestrians.

So IMO this all makes sense when the red arrow has a different timing sequence from the red ball, but if the two are identical, then I don't have a good explanation as to why to put in a red arrow when the NTOR signage should be sufficient