Special modes for emergency personnel sound great, but how do you determine if someone is really supposed to have access to it? It's one thing if you can't do anything special beyond perhaps seeing additional information. It's something else to be able to do something not normally allowed, such as blocking off an entire section of streets (something that could be severely abused). If there's a good way to give emergency personnel what they can use without it becoming a problem, then I'm all for it.
Regarding the initial question about being able to see where the emergency is on a divided road, I wonder if there can just be a note on the hazard that says what direction the road is going? It doesn't have to be a perfect mechanism, but basically 8 cardinal directions. N, S, E, W, NW, SW, NE, SE. It can be based solely on the direction of travel at that exact point and determined by the angle of the road at that point and whether it's on the right or left side of the road (different countries need to of course handle it differently depending on which side the cars drive on). You could probably get by with 4 directions instead of 8, but it could be confusing if you're right at a center division. That could be tested to see if it's a problem or not. If not, I'd just use the 4 major directions.
Main St (westbound)
Michigan - Northern LP.
Waze running on Samsung Galaxy S3.