In most states a vehicle will only be given a "salvage title" if it is been considered totaled. A total loss basically means that the repairs would cost equal or more than the car's actual cash value.
If you were rear-ended and do not have significant damage it is unlikely your vehicle will be considered a total loss. If this is the case you should be able to negotiate a settlement (paid normally in the form of a check) for the repairs and continue to drive your vehicle.
How to Deal with your Insurance Company Regarding Claims is an article that can help you when settling a claim.