Curve goes in different directions I have a single path as mesh and after I've converted it into a path there are some vertices going in the wrong direction.

For example at the top right and at the bottom in the middle there is also some weird things going on as seen in the lower picture.

If I apply a bevel object it looks a bit weird as you can tell.

Is there a way that all vertices have the same direction?

Here you can download the file
Please don't mind the Audi R8 and the German names of the layers.
The curve is going in different directions because there are gaps in the curves. In your case there are several point where the curve has a gap. It looks like it is a single continous curve but actually there are 2 end points on top of each other that only make it look like a single curve.
You can fix this by moving on of the overlapping endpoints away form the other and than filling it, use F to connect to points. The direction of the curve will then automatically be normalized. Just to be sure: when you are done with that you can also normalize the curve using Ctrl+N

   

How to find these overlapping points:
To find these point you can in Edit mode, hover of a point with the mouse and hit L. This will select all the connected points. You can than select the end points manually.