Researchers propose a fourth traffic light for autonomous vehicles

Daniel Sims

Posts: 1,335   +43
Staff
Through the looking glass: Regulators and motorists remain skeptical of self-driving cars, which are still nowhere near wide adoption. However, a group of researchers proposes that travel times and gas consumption can decrease if drivers let autonomous vehicles direct traffic using a fourth traffic light color.

Simulations from North Carolina State University researchers suggest a new kind of traffic light could speed up passage through intersections with the help of self-driving cars and distributed computing. The system would try to balance interactions between traffic lights, human drivers, and autonomous vehicles.

Under the proposal, when a certain percentage of vehicles approaching an intersection are self-driving, the light switches to the new color to inform motorists that it's coordinating with autonomous cars. Instead of stopping, going, or slowing down, the light instructs humans to copy the vehicle ahead of them, whether it proceeds through the intersection or waits for someone else to pass. When the percentage of self-driving cars falls below the threshold, the traffic light returns to normal.

The researchers originally proposed the concept in 2020, but that initial version relied on traffic light computers to direct the self-driving vehicles. The centralized approach proved vulnerable to communication disruptions with traffic light controllers. The updated experiment uses a more resilient distributed model wherein all the autonomous cars and the traffic-light computer talk to each other.

The fourth traffic light doesn't do anything to direct the robocars. It just tells the human drivers that the traffic computer and autonomous vehicles are negotiating traffic flow and that they should follow them.

So far, the researchers have only tested the proposal with computational model "microscopic" traffic simulations, but they show increased traffic speed. The experiments resulted in less time waiting at traffic lights and less fuel consumption when the proportion of self-driving cars reached 10 percent. The results improved the more autonomous vehicles got involved.

Autonomous penetration rates between 10 and 30 percent saw relatively small reductions in traffic delays, usually below 10 percent. Beyond that, however, the researchers say delays could fall by over 90 percent.

The idea has yet to go through real-world testing, but it could cut back on some autonomous-traffic incidents that have seen a rise lately. California transportation authorities recently complained to companies trialing self-driving fleets in large cities regarding many troubling cases.

Last June, a group of robotaxis in San Francisco stopped in the middle of an intersection for no apparent reason. Such glitches can erode already shaky public trust in autonomous vehicles, but we can't know yet whether traffic control through distributed computing would've prevented this situation.

Permalink to story.

 
And what happens when a human driver decides to act like he’s in a self driving car to get ahead of everyone else out of the intersection? A car crash happens.

This idea has an obvious flaw known as human behaviour…

Also what happens when a human driver is first in line? Do they drive after the actual lights? Do they have automatic priority? Do they get confused and make poor decisions?

this idea seems like it came from the computer science department rather than the infrastructure one…
 
I am not about to blindly follow any Tesla anywhere, no matter who may or may not be driving. When I feel like driving the wrong way down one-way streets, running stop signs, making left turns in front of oncoming traffic, crashing into police cars, running over kids, and blowing thru intersections and slamming into semi trailers, I step away from the tequila and hand my keys to someone else.
 
Even if you were up for the autonomous cars negotiating with each other to figure this out, why couldn't they just send the results to the traffic light so it could signal to the human drivers what they were supposed to do using one of the 3 traditional colors?

Also good luck on getting 100% of existing drivers trained and compliant on what this 4th color means.
 
Even if you were up for the autonomous cars negotiating with each other to figure this out, why couldn't they just send the results to the traffic light so it could signal to the human drivers what they were supposed to do using one of the 3 traditional colors?

Also good luck on getting 100% of existing drivers trained and compliant on what this 4th color means.

I think the key to it is, as in most new things, it will take time to become comfortable and knowledgeable about how it works and yes most people over 50 will have a hard time with it. But when cars became the norm it took time to have a left side and right side lanes so cars weren't driving wherever on the road they wanted to drive. If you go India and some other parts of the World animals pulling carts and cars interacting is a huge mess and that doesn't even account for each thinking the whole road is theirs to drive on wherever and whenever they feel the need.
 
My parents can’t even figure out how “those darn roundabouts” work!

Maybe a better idea would be to vary standard light timings based on predicted traffic from data that autonomous cars (and even non-autonomous cars) could provide.

YES absolutely!! As for roundabouts if people would stop stopping when entering them it would make things alot better!!
 
And what happens when a human driver decides to act like he’s in a self driving car to get ahead of everyone else out of the intersection? A car crash happens.

This idea has an obvious flaw known as human behaviour…

Also what happens when a human driver is first in line? Do they drive after the actual lights? Do they have automatic priority? Do they get confused and make poor decisions?

this idea seems like it came from the computer science department rather than the infrastructure one…

Yep, You can't quantify human stupidity!
 
In Canada, we've had light that isn't red, yellow or green for years:
blue-light-bottle-lg-4.png

However, it's not a good idea to use this in any combination with driving and I don't think that the proposed fourth light would be either! :laughing:
 
Last edited:
I think the key to it is, as in most new things, it will take time to become comfortable and knowledgeable about how it works and yes most people over 50 will have a hard time with it. But when cars became the norm it took time to have a left side and right side lanes so cars weren't driving wherever on the road they wanted to drive. If you go India and some other parts of the World animals pulling carts and cars interacting is a huge mess and that doesn't even account for each thinking the whole road is theirs to drive on wherever and whenever they feel the need.

Many new things are also, not actually good ideas? And never go anywhere. To me this seems like one of them. Luckily it doesn’t seem like it one of the more dangerous types, that’s dumb as balls, but ends up everywhere. Like stroads, crypto and adding machine learning features to refrigerators.
 
OHH COME OME ON! People do not pay attention to the cars in front of them as it is. People do not follow the current traffic rules. This is a monumentally naive suggestion from overly optomistic academics.
 
Even if you were up for the autonomous cars negotiating with each other to figure this out, why couldn't they just send the results to the traffic light so it could signal to the human drivers what they were supposed to do using one of the 3 traditional colors?

Also good luck on getting 100% of existing drivers trained and compliant on what this 4th color means.
Agreed. I see 0 reason, if autonomous vehicles decide they should go and there's some communications system, why they wouldn't just turn the light green.
 
Back