3 ms·

Permanent red on all lanes until traffic arrives may be better. It allows you to safely switch to green faster on whatever lane traffic arrives from.

MichaelCollins 4y ago
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.
- bombcar 4y ago
  Some around here blink yellow on the main road and red on the side street at night. Works decently well.
bell-cot 4y ago
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.
- Someone 4y ago
  > 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.
EricMausler 4y ago
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

MichaelCollins 4y ago

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.

bombcar 4y ago
Some around here blink yellow on the main road and red on the side street at night. Works decently well.

bell-cot 4y ago

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.

Someone 4y ago
> 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.

EricMausler 4y ago

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