As I've indicated repeatedly in the past, DUI roadblocks (or to use the more politically correct term, "sobriety checkpoints") are proven to be ineffective and are used primarily as a dragnet to raise revenue from citations for traffic, license/registration and equipment violations. Law enforcement agencies are finally ending the pretense that roadblocks are effective at catching drunk drivers (the basis for the Supreme Court upholding this Fourth Amendment violation) but are now justifying them as "deterrence" (i.e., frightening people).
They're praised as a deterrent but don't yield the most arrests
Mechanicsville, VA. June 17 – It was Friday, the opening night of the long Memorial Day weekend — prime time for nailing drunken drivers.
From 11 p.m. until 3 a.m. officers funneled nearly 800 cars through a sobriety checkpoint at the Hanover-Henrico county line on U.S. 360…
Before the evening was over, Hanover deputies had issued 33 summonses and arrested an additional 14 people on other offenses ranging from drugs to outstanding warrants on immigration violations…
Immobile, expensive and labor-intensive, sobriety checkpoints are the fishing net of roadway law enforcement — catching everyone who enters but keeping only the violators, including impaired motorists.
"DUI road checkpoints, in and of themselves, are not necessarily designed to catch people under the influence," said Sgt. Rob Netherland, who supervises DUI checkpoints and patrols for Henrico County.
But Netherland and other officials say checkpoints do provide a worthwhile deterrent against people getting behind the wheel after they drink — a complement to the mobile and focused "saturation patrols," in which officers hit the road and actively target motorists whose driving suggests they may be under the influence.
"It's kind of like shock and awe," Hanover County Sheriff's Office Sgt. Mike Trice said of checkpoints…
In 2006, Henrico County police conducted eight sobriety checkpoints, resulting in 23 DUI arrests — a small number compared with the 855 DUI convictions the county recorded that year from arrests on routine patrols and other anti-drinking initiatives.
The Hanover Sheriff's Office ran four sobriety checkpoints in 2006, yielding 12 DUI arrests. The county recorded 337 DUI convictions that year.
Four sobriety checkpoints run by Richmond Police last year netted three DUI arrests in a city that recorded 590 DUI convictions, though officers made 170 arrests on related and unrelated offenses.