I personally would say it is not worth it, having gone through it myself before and seen other LDRs fail time and time again (mine lasted a year and a half after we first moved away from each other). Probably more than 90% don't even make it past the first term. The reason for this is that the vast majority of people just aren't that loyal, especially at student age, no matter how much faith you have in them. New experiences offered at uni and the newly acquired independence from parents almost always trumps their loyal partner. I and almost everyone else who have been in a LDR can attest to that.
There will be plenty of others on here who'll disagree with me, many of whom will have been in currently successful LDRs for months or even years, but the fact of the matter is, those that last for years are exceptional cases to say the least. Those that actually make it through uni are so rare they are almost unheard of. Unless you have been together since early teens, I wouldn't bother.
My advice if you really want to go ahead with it:
One or both of you will almost certainly lose interest very quickly. If that is your girlfriend, learn to see the signs and break it off quickly instead of letting it drag on. If you lose interest, then don't string her along, even for 1 day. See each other as often as you can without it impacting on your work. Set aside specific times for Skyping or calling after Freshers' week when routine sets in. But be prepared, because statistically speaking, your chances are almost zero.