Sometimes even conservatives have good ideas. President Reagan, marking the start of National Drunken and Drugged Driving Awareness Week last week, compared operating a motor vehicle while intoxicated with hostile action against the United States.

"If a foreign power did to America what drunk drivers do in a single day," he said, referring to the fact that 25,000 Americans are killed in alcohol- and drug-related accidents each year, "we would consider it an act of war."

If anyone has any doubts about the validity of the president's statement, ask the family of Sadie Walton Yette, a Montgomery County school librarian who was killed on her way to a Christmas party two years ago.

She was a passenger in a car driven by her husband, Samuel F. Yette, when their vehicle was struck by another car in Riverdale. Prince George's County police arrested the driver of the second car.

Having known the victim as a gentle, loving mother of two sons, I mourned her loss along with other friends and relatives, and kept a watchful eye out for the outcome of this case. I recall that at the time of her death a presidential commission on drunk driving was calling for a national commitment to get more drunks off the country's streets and highways and urging that community service be required for those convicted.

But getting a conviction in these cases has been a problem. According to a Washington Post survey released in 1983, efforts to get drunk drivers off the roads by imposing stiffer penalties have failed, despite tougher state laws. The Post study found defense attorneys, in going to considerable lengths to protect their clients, had contributed to the severe weakening of new drunk-driving legislation. Thus, harsher laws had not led to markedly stiffer penalties.

In the case of Sadie Yette, the perpetrator was tried in August before a jury in a Prince George's courtroom.

After a three-day trial, it took the jury only 45 minutes to find the perpetrator guilty of drunk driving, speeding and driving without his glasses.

Between the time of the perpetrator's trial and his sentencing, President Reagan gave his anti-drunk driving speech.

A few days ago, Yette and his sons received a letter dated Dec. 17 from the Prince George's state's attorney's office saying the driver was sentenced by Judge William H. McCullough to "one year Department of Corrections, sentence suspended except for thirty days to be served on work release, three years probation with DWI program through the Division of Parole and Probation."

"It's ridiculous," Hunter Wolcott, president of the Washington chapter of Mothers Against Drunk Driving (MADD) said of the case. "We want people to realize that drunk driving is a felony. If the other person hadn't been drunk then they would've been able to deal with the eventualities of driving."

While I don't subscribe to the vindictive philosophy of some Old Testament God, there's no way that spending 30 nights in jail is a stiff enough sentence for a man who crushed out a woman's life with a car he was driving while drunk. In addition to 25,000 people who are killed every year by drunk drivers, 700,000 are injured and more than $20 billion is spent on medical bills.

Ironically, the president said that progress had been made in the battle to make the nation's highways safer. Indeed it has. Fatalities are at their lowest point in more than two decades -- and President Reagan gave private sector groups like MADD much of the credit. The roads are "safer than they used to be and getting safer still," according to the president.

But as the Yette case shows, much, much more progress remains to be made.

We've added muscle to the laws; now we need to add teeth to the sentencing.