Only if you have idiots for traffic planning. By now you can have sensors that detects vehycles on lanes and change it depending on the situation.
only two lanes are in use: permanent green until a car on the other lanes come.
We are definitely stuck with idiots for local traffic planning. And those clever sensors - there is a huge difference between (A) a traffic light checking that Feature Box in PowerPoint (or Flash, or Microsoft Bob, or whatever software the local traffic planners use), and (B) traffic sensor technology being usefully implemented at the light's real-world location.
I've see a lot of sensor failure modes which that algorithm would handle poorly - complete failure, failure to notice small/light vehicles (especially motorcycles / scooters / bikes), mis-reading which lane a vehicle is in, ...
I've also seen fancy sensor-equipped traffic lights where the traffic flow was improved by a power outage turning the intersection into a (legal default) 4-way stop. Major intersections. During rush hour.
> I've also seen fancy sensor-equipped traffic lights where the traffic flow was improved by a power outage turning the intersection into a (legal default) 4-way stop. Major intersections. During rush hour.
That fits one of the main points made in this article: traffic lights slow down traffic. Another one is that decreasing speed on intersections increases safety.
The magic of roundabouts is that they accomplish the latter without needing the former.
There is one of these on a backroad near me. I wish the sensor were farther away from the intersection so I wouldn't have to come to a complete stop just as it turns green.
The general traffic is probably 95% favored to the direction I am going, and I really wish they would just leave it green until the other direction actually needs it.
Maybe they have it this way on purpose to indirectly prevent speeding? I wonder if that's a consideration for traffic light logic or not
When traffic is light (e.g. at night), the traffic light can be scheduled to blink red in all directions. Then it is treated like a simple stop-sign intersection.
