Were they ever wired to keep a particular shape next to your driveway? If they were wired to hold their shape, the bark has expanded around the wire, the tree's circulation has been cut off. Check the tree needles with a magnifying glass to see if any insects or spots appear. 
See the blight description on these web pages.
https://extension.psu.edu/juniper-diseases
https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/needlecasts/phomopsis-blight
Submitting a sample to the Plant Disease Clinic may be necessary to make a definate diagnosis. There is a fee for this service.
 https://pdc.umn.edu/