Share what you've learned about the effect that transportation has on the environment with pupils and staff at your school. Make it clear why you want to take action on the school commute and what everyone can do to help.
You might want to use some of the data that you have from the survey you conducted - either from one class or the whole school.
Make sure that everyone knows what they need to do next. It might be hard to go from driving every day to cycling or walking but you can reduce your carbon footprint in less dramatic ways. The Sustainable Transport pyramid is a great resource for this - it shows people how by nudging to the next level they can make lower carbon choices.
Even if they can only switch one journey a week, that's a great start!