I understand that the emergency vehicle preemption system already knows the direction from which the emergency vehicle is coming. The way I think an intersection across the United States should be set up is what's shown in this picture. The Red line means that they have a red light. 

The green lines indicate the different directions that southbound people can travel, depending on their lane, and that they will be the only ones receiving a green light. I use the southbound section as an example because it is the one that is used the most when emergency vehicles try to get through the intersection. After all, further back on that southbound side, there is a state highway that connects to a Level 4 trauma center acute care hospital, where most patients in critical condition are being airlifted or transferred with lights and sirens to a hospital farther south. 

This is one of multiple lighted intersections that they have to navigate to reach the Level 3 trauma center hospital, which features a cath lab. What I've observed is that I'll be in the northbound lane, and both the northbound and southbound lanes will receive green lights, while the left turn lane will get a 'yield to oncoming traffic' signal. Personally, I see it as a problem, especially since I've driven an ambulance, and this intersection poses some concerns. 

That's because the left turn lane leads to three small towns that are well over half an hour away from any hospital. This means that if the ambulance has to turn left, it may get stuck or have to go around the vehicle in the left turn lane and use the center lane to make the turn, which is not ideal and not very safe. Which is why I'm wondering why the people who are programming the traffic lights don't set it up. 

So that when the emergency vehicle preemption system detects, in this example, an ambulance going southbound, it gives green to all southbound lanes and red to all other lanes in all other directions to clear out as many vehicles as possible on that southbound side. So that whether it's an ambulance, a state trooper, a sheriff's vehicle, or any other emergency vehicle, it may have all three of those lanes to use. Without any blockages or concerns about northbound traffic coming towards them, because if someone in northbound traffic doesn't realize that an emergency vehicle is moving southward, they may have to turn left. 

Because this is not coming from just a person who drives their own personal vehicle, but also from people who are firefighters, ambulance workers, sheriffs, state patrol, and police officers, and from me, a person who could be the one driving an ambulance. Additionally, this is a Minnesota intersection, so we do experience snow and stormy weather. That's when it's more likely that the transfer will be done via ambulance rather than helicopter, which means there may be poor visibility, posing an even greater risk because you can't see as far now. Yes, we, the ambulance drivers or first responders, will be driving with more care and not as quickly. However, the risk remains higher than in ideal conditions.

Additionally, you're not just putting the first responders in danger; if it's an ambulance, you're also putting the patient inside that ambulance in danger, as well as everyone in the intersection who got caught up in the accident. As well as again if it's an ambulance there is now one less ambulance for that district which can be pretty big for coverage area and now all the ambulance that service that coverage area are going to be caught up in this accident and the response times for 911 calls that happen in that district are going to be longer until they get a ambulance to cover that service area. 

My Hope is that this answers some questions and brings to light some safety concerns that some people may not have considered or realized, potentially starting the wheels in motion to change safety standards and how lights are programmed when the emergency vehicle preemption system is activated. 

If you have any questions or need further clarification on what's being asked or what's being said, please don't hesitate to ask.  I know I've probably done a poor job explaining this and a horrible job asking questions I wanted to ask.

I have a question about the traffic light system and why it's not implemented uniformly across the entire United States, as well as the standard regarding emergency vehicle preemption.