What is the future of the Traffic signal? Well, with new techologies traffic signals are going to more smarter for driverless cars will able predict how long the red light going to change to green. Traffic signal will able share infomation via wireless to driver.
I would suspect that within 20-30 years, our traditional traffic signals will be replaced with LED screens, like the variable speed signs, with symbols to indicate the action that traffic should take. These could simply be squares to replace the existing 3 light installations, or could be an entire billboard sized sign, to make adjustments, give special actions for bikes, relay messages, etc. Much like the two phase lights were still used in some locations until very recently, it will likely be another 20-40 years before the 3-phase lights are completely replaced.
That being said, I also see a larger number of alternate intersections, mainly roundabouts but perhaps even Michigan Lefts/Superstreets being installed to increase the flow of traffic and reduce the amount of time sitting at lights, and the overall need for traffic signals.
Quote from: TEG24601 on June 21, 2014, 11:31:37 AM
I would suspect that within 20-30 years, our traditional traffic signals will be replaced with LED screens, like the variable speed signs, with symbols to indicate the action that traffic should take. These could simply be squares to replace the existing 3 light installations, or could be an entire billboard sized sign, to make adjustments, give special actions for bikes, relay messages, etc.
I very much doubt that one large screen would replace having three to five separate indications - there's many more ways for that screen to malfunction compared to just having an indication burn out or get stuck on.
I suspect in 30 years traffic signals will pretty much look the same as today, but hopefully function much better with more intelligent controllers/software.
Quote from: Tom895 on June 21, 2014, 03:12:45 AM
Well, with new techologies traffic signals are going to more smarter for driverless cars will able predict how long the red light going to change to green.
I have my doubts about that as well. With today's technology we could easily provide information on how long until the light turns green via a countdown display for many signals.
Quote from: Revive 755 on June 21, 2014, 01:23:36 PM
Quote from: TEG24601 on June 21, 2014, 11:31:37 AM
I would suspect that within 20-30 years, our traditional traffic signals will be replaced with LED screens, like the variable speed signs, with symbols to indicate the action that traffic should take. These could simply be squares to replace the existing 3 light installations, or could be an entire billboard sized sign, to make adjustments, give special actions for bikes, relay messages, etc.
I very much doubt that one large screen would replace having three to five separate indications - there's many more ways for that screen to malfunction compared to just having an indication burn out or get stuck on.
I suspect in 30 years traffic signals will pretty much look the same as today, but hopefully function much better with more intelligent controllers/software.
Quote from: Tom895 on June 21, 2014, 03:12:45 AM
Well, with new techologies traffic signals are going to more smarter for driverless cars will able predict how long the red light going to change to green.
I have my doubts about that as well. With today's technology we could easily provide information on how long until the light turns green via a countdown display for many signals.
The LED screen idea is also very costly, IDOT doesn't have that kind of money.
I think the current design will stick around for another 50 years. It's a design that's been proven to work well, and it also allows for the colorblind to be able to tell the indication better. The only thing I see changing about them in the near future is the signals getting thinner because most companies don't provide parts for incandescent signals any more.
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
Even then in whatever transition period, I'd expect we start retrofitting traffic lights with wireless transmitters, so that adjacent driverless cars know what the signal is and when it will change without having to rely on visual signals. As far as the design itself, those who still drive their own cars would presumably see something that looks the same as it does today.
Quote from: corco on June 21, 2014, 04:14:08 PM
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
and then you will need to build pedestrians under / overpasses after that.
Hopefully they are eventually timed better so that you don't have to stop at every light going through town.
Quote from: US 41 on June 21, 2014, 08:23:05 PM
Hopefully they are eventually timed better so that you don't have to stop at every light going through town.
If i go the posted speed limit, the lights should be timed so that i don't get stopped at a red light. Simple enough request. The problem is, the guy in the other direction is thinking the exact same thing. There are very few roads in America where good two-way progression is even possible.
Typical time distance of a high speed arterial:(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRandom%2F05milespacingtimedistance.jpg&hash=c53e7de2b300ca510778c45b4146381aefe937a6)
Quote from: Joe The Dragon on June 21, 2014, 08:17:03 PM
Quote from: corco on June 21, 2014, 04:14:08 PM
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
and then you will need to build pedestrians under / overpasses after that.
Not necessarily, but maybe. Jaywalking would likely become a lot more dangerous/illegal. Or all humans will have transponders on them that alert adjacent cars that there is a pedestrian around. My smartphone already knows when I'm walking- that technology pretty much exists already. Obviously we're talking 1-200 years out, so who knows, but I do expect robots to have more or less taken over the world from a traffic management perspective, with humans basically doing as the neural hive mind tells us. Just depends on how much free will we're willing to give up in the name of efficiency. Judging by the trends of the last 100 years, I'm not optimistic.
Quote from: corco on June 21, 2014, 10:07:52 PM
Quote from: Joe The Dragon on June 21, 2014, 08:17:03 PM
Quote from: corco on June 21, 2014, 04:14:08 PM
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
and then you will need to build pedestrians under / overpasses after that.
Not necessarily, but maybe. Jaywalking would likely become a lot more dangerous/illegal. Or all humans will have transponders on them that alert adjacent cars that there is a pedestrian around. My smartphone already knows when I'm walking- that technology pretty much exists already. Obviously we're talking 1-200 years out, so who knows, but I do expect robots to have more or less taken over the world from a traffic management perspective, with humans basically doing as the neural hive mind tells us. Just depends on how much free will we're willing to give up in the name of efficiency. Judging by the trends of the last 100 years, I'm not optimistic.
I'd assume vehicles would still have sensors checking for obstacles ahead, which would include pedestrians whether they be legal or not.
Quote from: corco on June 21, 2014, 10:07:52 PM
Quote from: Joe The Dragon on June 21, 2014, 08:17:03 PM
Quote from: corco on June 21, 2014, 04:14:08 PM
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
and then you will need to build pedestrians under / overpasses after that.
Not necessarily, but maybe. Jaywalking would likely become a lot more dangerous/illegal. Or all humans will have transponders on them that alert adjacent cars that there is a pedestrian around. My smartphone already knows when I'm walking- that technology pretty much exists already. Obviously we're talking 1-200 years out, so who knows, but I do expect robots to have more or less taken over the world from a traffic management perspective, with humans basically doing as the neural hive mind tells us. Just depends on how much free will we're willing to give up in the name of efficiency. Judging by the trends of the last 100 years, I'm not optimistic.
Why stop with transponders? Imagine a neural-chip in each and every person implanted where the spinal cord meets the brain, providing direct internet access to your brain and telepathic control of anything with a computer chip. Of course, the downside is that authority could track your every move, read your mind, and even control your actions and re-write your memories.
Quote from: vdeane on June 22, 2014, 07:46:22 PM
Quote from: corco on June 21, 2014, 10:07:52 PM
Quote from: Joe The Dragon on June 21, 2014, 08:17:03 PM
Quote from: corco on June 21, 2014, 04:14:08 PM
I suspect the eventual, long term result is that they go away entirely. It will probably be easier for driverless cars to communicate with other cars to know where they are and how to flow most efficiently, in a sort of neural network/hive mind, than to design driverless cars that can recognize every single road sign/signal/lane markings/etc, though that requires all/a vast majority of cars to be driverless, so I'd guess that's at least 100 years out. Perhaps manually driven cars will be retrofitted with a HUD or some screen that fills the needs that signs/lane markings/traffic lights do now, with instructions from adjacent auto-cars that guide the human driver to drive safely in a new, computer managed traffic flow.
and then you will need to build pedestrians under / overpasses after that.
Not necessarily, but maybe. Jaywalking would likely become a lot more dangerous/illegal. Or all humans will have transponders on them that alert adjacent cars that there is a pedestrian around. My smartphone already knows when I'm walking- that technology pretty much exists already. Obviously we're talking 1-200 years out, so who knows, but I do expect robots to have more or less taken over the world from a traffic management perspective, with humans basically doing as the neural hive mind tells us. Just depends on how much free will we're willing to give up in the name of efficiency. Judging by the trends of the last 100 years, I'm not optimistic.
Why stop with transponders? Imagine a neural-chip in each and every person implanted where the spinal cord meets the brain, providing direct internet access to your brain and telepathic control of anything with a computer chip. Of course, the downside is that authority could track your every move, read your mind, and even control your actions and re-write your memories.
I'm fairly certain there are several movies and TV series explaining why that's a bad idea.
A video produced a couple years ago detailing a driverless car intersection:
http://vimeo.com/37751380 (http://vimeo.com/37751380)
(not sure if you can embed Vimeo...can't figure it out)
The big question is when NYC is going to get rid of the old signal controllers and also start using detector loops like the rest of the world. Plus start to use mono tube mast arms instead of the double guys that they still even have specially made for them for newer installations even post 9-11 where many mast arms were destroyed by the fall of the towers.
Right now all signals are on set timers, even in Staten Island where the loops could be used as well as parts of the Bronx and Queens. I know, too, that the double guys are part of nostalgia and it helps near the city's borders to determine if its legal to make a right turn on red despite NYC's unusual default NTOR. If you see span wire, you know its okay as you are in Nassau or Westchester where its legal, but if you see those double guys you know to stay put until the light turns, but other than those two I think NYC could move forward.
Quote from: roadman65 on June 26, 2014, 12:14:46 PM
The big question is when NYC is going to get rid of the old signal controllers and also start using detector loops like the rest of the world.
How about never? Does never work for you?
Detection loops, used to trigger traffic signal cycles, are exactly what NYC doesn't need, particularly in the most congested parts of the city. The free flow of traffic is accomplished, insofar as possible, by *not* allowing side-street traffic to turn a signal red on the main streets. Until you've lived and driven there, you will not understand. It's currently possible to traverse Manhattan Island from north to south (or the reverse) in an incredibly short period of time, if you're on a one-way avenue. Why would you tamper with that?
Quote from: SidS1045 on June 26, 2014, 03:11:37 PM
Quote from: roadman65 on June 26, 2014, 12:14:46 PM
The big question is when NYC is going to get rid of the old signal controllers and also start using detector loops like the rest of the world.
How about never? Does never work for you?
Detection loops, used to trigger traffic signal cycles, are exactly what NYC doesn't need, particularly in the most congested parts of the city. The free flow of traffic is accomplished, insofar as possible, by *not* allowing side-street traffic to turn a signal red on the main streets. Until you've lived and driven there, you will not understand. It's currently possible to traverse Manhattan Island from north to south (or the reverse) in an incredibly short period of time, if you're on a one-way avenue. Why would you tamper with that?
Agreed. It drives me nuckin' futs when I'm driving along a 50 mph highway in the country and a car pulls up to a signal and changes it. What a waste of gas! At least have a time-out period, not just instant gratification for the 1% of people using the side road.
I did not say Manhattan? In Staten Island and parts of the Bronx if you read the print! Anyway, as far as equipment goes, they still use the old analogue controllers. You can still update the equipment and not have the detector loops.
Ans yes, I have driven NYC and its a nightmare already. I do like the fact you can drive 10th Avenue and go for blocks without hitting a red signal. True, crosstown is much different, but something has to give. You cannot have both ways as letting crosstown be the default would then have the avenues be the one's to stop at every block.
The signals, though, on Fifth Avenue could be modified with some mast arms as many intersections use side mounts with one of the two main signal heads on the near side of the intersection. Now living in Florida where we have the traditional side by side placement of heads, I can tell you having one on the left and the other on the right is better as standard placement is not seen when transiting behind a truck. So opposing mast arms are great in my opinion, but some on that particular artery do not even have them, so NYC should do that there.
Quote from: roadman65 on June 27, 2014, 09:20:57 AM
I did not say Manhattan? In Staten Island and parts of the Bronx if you read the print!
Staten Island and the Bronx still have main thoroughfares whose smooth flow would be tanked completely by starting to use detection loops on the side streets.
Quote from: roadman65 on June 27, 2014, 09:20:57 AMThe signals, though, on Fifth Avenue could be modified with some mast arms as many intersections use side mounts with one of the two main signal heads on the near side of the intersection. Now living in Florida where we have the traditional side by side placement of heads, I can tell you having one on the left and the other on the right is better as standard placement is not seen when transiting behind a truck. So opposing mast arms are great in my opinion, but some on that particular artery do not even have them, so NYC should do that there.
The signals on Fifth Avenue are deliberately not on mast arms for aesthetic reasons. Commercial vehicles are banned from Fifth Avenue between 26th and 85th Streets and 86th to 125th Streets, so getting stuck behind a truck and being unable to see the traffic signal in those areas is not an issue.
Quote from: SidS1045 on June 27, 2014, 10:20:37 AM
Quote from: roadman65 on June 27, 2014, 09:20:57 AM
I did not say Manhattan? In Staten Island and parts of the Bronx if you read the print!
Staten Island and the Bronx still have main thoroughfares whose smooth flow would be tanked completely by starting to use detection loops on the side streets.
Quote from: roadman65 on June 27, 2014, 09:20:57 AMThe signals, though, on Fifth Avenue could be modified with some mast arms as many intersections use side mounts with one of the two main signal heads on the near side of the intersection. Now living in Florida where we have the traditional side by side placement of heads, I can tell you having one on the left and the other on the right is better as standard placement is not seen when transiting behind a truck. So opposing mast arms are great in my opinion, but some on that particular artery do not even have them, so NYC should do that there.
The signals on Fifth Avenue are deliberately not on mast arms for aesthetic reasons. Commercial vehicles are banned from Fifth Avenue between 26th and 85th Streets and 86th to 125th Streets, so getting stuck behind a truck and being unable to see the traffic signal in those areas is not an issue.
So commercial traffic is allowed for one block between 85th and 86th? Why is that?
Probably because 86th ends at 5th Ave even though it's the major east-west highway for the next few blocks, with 85th taking over that role on the other side of 5th Ave. Central Park disrupts the grid.
Quote from: vdeane on June 27, 2014, 08:24:08 PM
Probably because 86th ends at 5th Ave even though it's the major east-west highway for the next few blocks, with 85th taking over that role on the other side of 5th Ave. Central Park disrupts the grid.
That reminds me...Central Park is a disruptive asshole and needs to be dealt with. I vote for paving it over and building a large soda bottling plant. It will employ thousands of thirsty New Yorkers.
/sarcasm
What about this?
http://youtu.be/2_QsY7govq0 (http://youtu.be/2_QsY7govq0)
Quote from: SidS1045 on June 26, 2014, 03:11:37 PM
Quote from: roadman65 on June 26, 2014, 12:14:46 PM
The big question is when NYC is going to get rid of the old signal controllers and also start using detector loops like the rest of the world.
How about never? Does never work for you?
Detection loops, used to trigger traffic signal cycles, are exactly what NYC doesn't need, particularly in the most congested parts of the city. The free flow of traffic is accomplished, insofar as possible, by *not* allowing side-street traffic to turn a signal red on the main streets. Until you've lived and driven there, you will not understand. It's currently possible to traverse Manhattan Island from north to south (or the reverse) in an incredibly short period of time, if you're on a one-way avenue. Why would you tamper with that?
Detectors don't necessarily mean that one car pulling up on the side street automatically and immediately turn the major street red.
Modern controllers can be set so that when side street traffic is detected, it will have to wait for a specific point in the cycle before the cross street is served. This aids in progression. With detection, the controller can also be set so if there is no side street traffic detected then the side street phase is completely skipped to allow more time for the main street--on old, timed signal controllers without detection, you must always serve the side street regardless of whether a vehicle is waiting or not. Modern controllers with detection can also skip pedestrian phases if nobody is there to push the button.
Modern controllers also have the benefit of being able to communicate with a central network system to help keep time and coordination plans in sync. For traffic incidents, operators can remotely change the signal settings to help keep traffic flowing. Even if you devise perfect signal timing and progression within a corridor, a electromechanical controller that doesn't properly keep time can cause one signal to fall out of sync and mess up progression along the corridor.
I agree with this statement. You can set detectors not to respond immediately! On Hylan Boulevard on Staten Island and on the Grand Concourse, modern signal technology would help improve the steady flow.
Back to Manhattan, Central Park West has many signals that are on one way streets inward that are only there for pedestrians as the park is to the opposite side of the street. How much unnecessary stops does one make for nobody even crossing the street vehicle or pedestrian? You could advance one more block if you have the buttons installed where the pedestrian activates the signal and also it can be delayed till the next cycle for the light on CPW to turn red keeping sync with the rest of the signals.
Like someone once said on this forum how behind in the times NYC is with technology as he pointed out it was rather recently NYC got fiber optic cables installed. The same with traffic signals I can see and I believe he said the same thing when he posted that.
BTW, those side mount signals on Fifth Avenue look horrible. Mast arms would improve the look around Rockefeller Center tremendously! Plus some intersections like at 42nd Street have them already put in place as well as a few other intersections rather recently too.
Quote from: roadman65 on June 28, 2014, 07:17:23 PM
I agree with this statement. You can set detectors not to respond immediately! On Hylan Boulevard on Staten Island and on the Grand Concourse, modern signal technology would help improve the steady flow.
Back to Manhattan, Central Park West has many signals that are on one way streets inward that are only there for pedestrians as the park is to the opposite side of the street. How much unnecessary stops does one make for nobody even crossing the street vehicle or pedestrian? You could advance one more block if you have the buttons installed where the pedestrian activates the signal and also it can be delayed till the next cycle for the light on CPW to turn red keeping sync with the rest of the signals.
Like someone once said on this forum how behind in the times NYC is with technology as he pointed out it was rather recently NYC got fiber optic cables installed. The same with traffic signals I can see and I believe he said the same thing when he posted that.
BTW, those side mount signals on Fifth Avenue look horrible. Mast arms would improve the look around Rockefeller Center tremendously! Plus some intersections like at 42nd Street have them already put in place as well as a few other intersections rather recently too.
Washington DC is pretty similar to New York in that the vast majority of the signals are on pure timer. They don't even have a push button for the pedestrians.
But one place where they do tend to have push buttons are mid-block pedestrian crosswalks or on similar intersections where a one-way street at a T intersection goes in the direction away from the T. (Like 3rd and Madison near the Capitol) Since there are no cars on the minor direction, the ped should push the button to cross the street. In fact, there are usually relatively large signs at such places reminding peds to push the button at these corners, since it's not required at the vast majority of corners.
In dense central business districts, pre-timed signals work quite well. There are 2,800 traffic signals in Manhattan alone. The cost involved to install and maintain such a large detection system doesn't seem justified.
Keep this in mind... No detection can be better than bad detection. Do you really trust that NYC DOT would be capable of providing reliable detection for all 2,800 signals? At any given time, 10% of the detection would be broken/faulty leading to potentially worse traffic flow in Manhattan than what a pre-timed system could provide.
Tradephoric does have a point though. Pre-timed signals do work especially well in a dense urban core, especially if the streets are laid out on a grid and/or if the streets are one way. (My understanding of New York City--I've never been there personally--is that there is a pretty solid two-way grid system on most streets but not a lot of left turn phasing, so at least some decent progression should be possible.)
I remember being especially impressed by the street grid in downtown Portland, OR when I was there several years ago. One way streets and pre-timed signals were great. They worked in such a way that you always hit a green wave if traveling right about at speed limit. The street spacing and signal timing was also such that if you happened to be walking at a steady pace against the flow of vehicular traffic, you nearly always hit the walk signal at the intersections.
With that said, side street detection can be beneficial to arterial coordination in the absence of ideal conditions such as an evenly spaced grid.
Quote from: roadfro on June 29, 2014, 02:31:57 PM
Tradephoric does have a point though. Pre-timed signals do work especially well in a dense urban core, especially if the streets are laid out on a grid and/or if the streets are one way. (My understanding of New York City--I've never been there personally--is that there is a pretty solid two-way grid system on most streets but not a lot of left turn phasing, so at least some decent progression should be possible.)
NYC is made up of 5 different boroughs. Manhattan is largely a one-way grid. The island is much longer N/S than E/W. So for most of Manhattan, you have about 8-15 avenues going N/S, the vast majority of them are one-way and relatively wide. Traffic favors the avenues and the signal progression favors the one-way avenues. You also have many E/W streets, about 1/20 of a mile apart, but most of them are one-way and only allow one lane of traffic. The street progression works great in Manhattan.
Staten Island has no significant regular grid.
The Bronx loosely continues Manhattan's grid, but we don't have as many avenues as tightly together as you do in Manhattan. Many of the avenues and streets aren't significantly orthogonal and most major avenues and streets are two-way instead of one-way.
Brooklyn and Queens have several grids within their layout that sometimes meet at odd angles. (I.E. see Dahill Avenue in Borough Park where the Brooklyn grid of numbered avenues and streets meets the Flatbush grid of East (and West) numbered streets and lettered avenues, Broadway also cuts across two grid patterns). Unlike Manhattan, the largest avenues and streets are largely two-way instead of one-way. Progression does not work as easily as it does in Manhattan. But at times, since there is a regular grid, the traffic controllers are programmed to provide priority for one of the directions (like towards Manhattan in AM rush, or away from the baseball stadium on Northern Avenue when the baseball game is supposed to finish, etc). Of course, traffic progression in such a case is miserable if you're going the other way.
I'm of the opinion that they'll remain largely unchanged visually but will become smarter on the back end. Once the signals can communicate with each other or with a central traffic system, computers can automatically adjust the timing to suit current traffic conditions.
Once driverless cars become more common and car-to-car communication standards develop, I don't doubt that there will at least be some research done on tying the automated cars in to the traffic control network. This would allow the traffic planning computer to assign suggested speeds to the cars to minimize delays through the whole network. For example, if a traffic signal could see incoming groups of cars and calculate when they'll arrive at the signal, they could then suggest that the cars from the north slow down and the cars from the east speed up so they both can reach the signal on green and not have to stop.
Quote from: realjd on June 30, 2014, 07:26:38 AM
I'm of the opinion that they'll remain largely unchanged visually but will become smarter on the back end. Once the signals can communicate with each other or with a central traffic system, computers can automatically adjust the timing to suit current traffic conditions.
What you describe is referred to as an adaptive signal system. While not completely unknown, this technology is not very widespread -- primarily due primarily to cost, and less so for infrastructure needed (comm systems, additional detection, etc.). In many places, communications between signals and a central hub simply allows for automatic clock adjustments and remote manual upload/changes of signal timing patterns (as opposed to driving to the signal to load new timing plans).