I've been in one for 10 years, and we even married last year, despite still not living together,... So I would say that LDRs can work, but this requires some conditions. As far as I can see in decreasing order of importance:

• keep regular contact (we phone each other almost every day)
• trust the other person (which does not mean one can't feel jealousy, but some basic trust must be there, otherwise things go down quite quickly).
• be open to the other person: distance can easily cause misunderstandings, so if you keep too much to yourself, it will be more difficult to solve problems.
• always have something planed together (be it in a couple of weeks or months)
• eventually plan to live together (I wouldn't like to be indefenitely in a LDR, even though I have been in one for a sizeable chunk of my life, now).
• be capable of quickly starting and ending arguments: conflicts are a normal part of a relationship. If you can't argue with one another because of the distance, the relationship won't survive it. So sometimes you have to get into arguments, even in the short time you have to be together. If you can't quickly patch it, things won't go smoothly.

LDRs also have their advantages:

• you can be very autonomous
• by living in different contexts, your partner can enrich your life (you meet different people, visit different places, etc)
• you avoid the attrition of routine
• the fact that your relationship can survive despite the distance is a good testimony to its value.
• despite being shorter, the times you spend together are more memorable and often of higher quality.

Of course, LDRs have their downsides, that you will have to learn to manage:

• feelings of loneliness (like a single, you can't count on your partner to "fill" your life)
• it's more expensive than living together, and there are additional costs related to travel expenses or phone calls.

All in all, I think it's hard to predict if you will fare well or not in a LDR. The best is probably to try, and then see how it goes,...

Good luck!