state law or Constitution state law or Constitution state law or Constitution legal in Massachusetts DUI checkpoints state law or Constitution state law or Constitution U.S. constitution doesn’t prohibit DUI checkpoints DUI checkpoints state law or Constitution state law or Constitution state law or Constitution state law or Constitution 13 U.S. states Governors Highway Safety Association (GHSA) sobriety checkpoints Governors Highway Safety Association state law or Constitution Sobriety Checkpoints Governor’s Highway Safety Association state law or Constitution some states, DUI checkpoint state law or Constitution