This happens all the time. You mentioned my state. Here we did have to get a Judges order but it was really no hassle doing so. I didn't have much experience on the street but it has happened. There were cases (exceptions) were a suspect was taken to the hospital because we feared for his (the suspects) own life and in that case no order was needed. I kinda had to laugh at the other posters comment about 5 guys holding the person down while blood was being drawn (vivid memory of one such encounter). In N.J. driving is a privilage and if one refuses even the field sobriety test it is an automatic revokation of driving privilages.
Take care. Billylll