I agree with the answers above. Communicate with the person. Do your part and let them do theirs. There is no reason to assume that they are not as committed as you are, and it is best to give them the benefit of the doubt, even if that seems a little nerve-racking. If you are very nervous about it, perhaps the 100-mile trip might be worth it. 

You might consider directly asking your partner how he or she feels about the project, about his/her sense of urgency, etc. 

Going into a project knowing so little about the other responsible party is difficult and nerve-racking, but your partner could end up being very dedicated and timely in his/her work. This may be a chance for you to test your patience, put in the work on your own end, take a deep breath and wait to see how well your partner holds up the other end.

I agree that setting definite deadlines are important, as well as making sure that is very clear who is to do what. It is very easy to misunderstand each other in a situation like this. Create a document that actually spells out what each person will do and when they will do it.

I recently had a very similar project for my on-line Master's program. Given that the project was heavily weighted, I was very worried about my partners (either they would not pull their part, or I would not be at their level).

In order to make sure everyone was happy with the progress, we set deadlines, reviewed the work of everyone, and spoke a lot about what needed to be done, revised, and completed.

One can easily tell about another person's commitment to education, even if one does not meet face-to-face. Email the person, discuss the plan, ask for input. Depending upon their response, you will be able to tell how "urgent" he or she is as well.

First, I guess I don't see why you need to gauge their sense of urgency.  If this is your partner and you're stuck with them, just do your part and see what happens.  As far as meeting, I suppose you guys could do Skype if you both feel comfortable doing that.  Or you could just trade the text back and forth, perhaps using the features on Microsoft Word that allow you to collaborate.