Notification Centre in iOS7
It took about 3 weeks until driving instructions where shown on my iPhone's today screen. I guess it simply takes a while until it decides to have gathered enough information about your behaviour to show up specific driving information in your today screen.

For example in my case it shows me the time to work every monday to friday, but not on the weekends. So it had to record my behaviour for a few weeks until it knows that I don't drive to the office on the weekends.

So just wait a while and it will "fix" itself.