My oldest 2 have to get up a half hour before I leave on schooldays. They are a 10 minute walk from school, so actually need to get up much later than I get them up.
I get them up for a half hour of chat, breakfast, money distribution, have you got whatevers, etc.
I have to go to work, dh is here, but I wouldn't see them otherwise.
They get themselves packed up and have only been late about twice in 3 years (forgotten PE bag, etc).
I have seen that mine have taken total responsibility for organisation. Its been a wonderful evolution, and they are amazed that their friends couldn't cope at weeks away when they had to attend camp lectures/activities.
My advice to you would be to have a frank discussion with your children as to why you need to leave so early. Be honest with them. Let them know that you can only consider this career move now that they are mature enough to cope. Then map out their daily schedule, so that they have a visual picture of where they need to be and at what time, etc. Include your travel time, location, and so on. Build in a coping plan for the days when things go wrong.
That would include you being able to respond to phone calls (ie, you having a bluetooth headset, so that you can safely talk on your journey to work). Having a breakfast together has worked for us, its very sociable, but takes organising the night before.
The upside for me has been that (due to the visual schedule) mine now have a window of opportunity (about 40 minutes) to catch up on stuff. One does 'forgotten' homework, and the other tends to the perfection of image. My less stressed mommy friends fill me in on how relaxed they seem since this routine has started.
Oh, and I am very strict on them leaving together, both involved in the locking up of the house, keys put safely away on their person, etc. They 'experimented' with them leaving separately (ie, the dawdler lagging behind, who was unfortunately the one who wouldn't have locked the door, and so on).
We talked, and talked and talked about how this was, and why it was as it was, and I think it has worked well. My dh is at home, but due to health issues, is more or less, not in a position to help them.
The interesting point for me is that they both have a huge appreciation for safety, and are very careful of keys, etc. They also regularly ask how my day has gone, and when I ask them how their day has been, I now get a real answer.
Whoops, massive reply. Sorry, hope its been helpful 