Question
I noticed elsewhere you indicate that Blue Point Junipers grow to about 3.5' wide...I have a row of 6 Blue Points and was told to plant them on 4' centers because they grow to about 4'. After 15 yrs they're doing beautifully except they're encroaching terribly in my neighbor's driveway as they've grown to about 8' wide! Is there a variety that remains closer to 4'? Thank you.

Answer
I would say it needs pruning. Annual pruning required to keep it trim; twice a year to keep it in colonnade shape
Here is a web link that gives detail instructions on how to prune this tree to keep it narrower.  http://www.ehow.com/how_7414758_prune-blue-point-juniper.html
It would be better to prune these established trees rather than changing the species.