Nervous wreck!!!

I am so nervous about this third baby! I'm scared I won't be able to make it to the hospital in time. My first came right at 4hours and my second came right under 2. What should I do if baby starts coming before I can make it to the hospital? I've read a few things but they just say call 911 so not very helpful because I already know that. I probably shouldn't be worrying about it as much as I am but it's like this fear of something going wrong and losing the baby somehow. Sorry if this is the wrong group!!