When people are convicted of drunk driving, many are often forced to use ignition interlock systems. That means that when they get into their car to drive, they must take a breath test by blowing into a pipe. If their blood-alcohol level is over the legal limit of .08, their vehicles won't start. It's considered a way to keep them in check and potentially prevent further drunk driving accidents.
It's possible that similar devices could make their way into all vehicles at some point in the future, not just the vehicles of convicted drunk drivers. According to the LA Times, the federal government is feeding money into research about alcohol-sensing technology in vehicles. There's already $10 million devoted to the cause over the next several years, and a new federal transportation bill could add an additional $24 million.
There are a couple ways it could work. Besides breathing into a tube, technology being researched may be able to sense alcohol by "sniffing" a driver's breath. Another version could detect alcohol in a person's blood through laser technology.
The idea may run into some obstacles. For one thing, the restaurant industry is not happy about it. It's possible that the devices would detect alcohol below the legal limit and prevent people from driving if they are not legally drunk. People would be less likely to order a glass or two of wine with dinner if they know they won't be able to drive home.
There's also the likelihood that the technology would fail some of the time. Even if the systems worked 99.99966 percent of the time, according to the Times, an average of 4,000 Americans a day would not be able to start their cars because the technology failed.
Others would argue that it's a small price to pay if the technology can save lives by preventing drunk drivers from being on the roads.
Source: LA Times, "Should future cars curb drunk drivers?" Dan Turner, March 28, 2012