I commute 50 miles a week by bicycle, but the current crackdown against drunk driving has made me feel only slightly safer.

I support groups like Citizens for Safe Drivers and Mothers Against Drunk Drivers. Police departments setting up "sobriety checkpoints"--to stop and examine motorists for drunken driving, especially on Friday and Saturday nights--have my thanks. I'm delighted that in Quincy, Mass., street signs announce: "As of Jan. 15, 1982, Drunk Drivers Arrested in Quincy Will Be Jailed and Legally Penalized." And I hope that 110 members of the House of Representatives succeed in passing their bill to create uniform and mandatory penalties for convicted drunken drivers.

But it's not enough. The grimmest statistic of all is insignificantly altered by the new outrage and toughness: one out of two of us is likely to be involved in an alcohol-related crash. Today, tomorow, sometime. Down the road, on the road.

If the next 10 years are like the past 10 years, 250,000 citizens will be killed in these crashes. Among the small percentage of drunken drivers who are caught and convicted, as many as eight out of 10 will be put on probation or have their sentences suspended or deferred.

Despite the welcome fervor of the crackdown, highway safety research from France and England shows that zeal for tighter laws and stricter enforcement fades after a few months.

What wouldn't fade is some form of public branding of the drinking driver. Suggestions are being made that the license plates of persons convicted of driving while intoxicated bear special letters by which the rest of us could watch out for them.

The idea has merit, but it lacks punch. Greater visibility is needed. My own solution is that convicted drunken drivers should be forced to have their vehicles painted Day-Glo orange.

Recognition would be immediate. Safety-conscious motorists--and bicyclists--who have gone beyond defensive driving to the more crucial art of survival driving would know to get out of the way when orange cars come near. Drunk driving would be a color- coded crime. Criminals would be on the loose, but not on the sly.

It would be a fit form of punishment: public shame heaped on those who abuse public space. Society's message to the drinking driver would be clear. If you want to paint the town red, you'll do it in a car painted optic orange.

The advantage of punishment by marked car is that it is the middle way that has long been needed. From my bike lane, I dream of the day when anyone convicted of drunken driving would never be allowed to drive again --period. I had a friend recently killed by a drunk driver, on a neighborhood street. My 80- year-old aunt, crossing a street in a walkway and with the light and walk sign with her, was hit by a driver with a record of drunk driving. My aunt--Irish and tough of limb--survived and collected $50,000. But she was crippled.

Would the advancing glare of a Day- Glo orange car have saved my friend and protected my aunt? I can't say for sure, but the current methods of saving and protection are shamefully weak. Alcohol is the nation's most abused and dangerous drug. Automobiles are the nation's most abused and dangerous machine. But the cultural glorification of the lethal two is so strong that no legislature would ever do what is needed: permanently forbid drinkers to drive.

Short of that, orange cars would still give offending drivers access to the roads--which most judges are allowing anyway--but they would give the law- abiding citizen an automatic alert that danger is near.

Paint jobs on criminals is not an entirely untested approach. Bank robbers are being caught when their getaway satchels explode and splatter red paint on them. If suspected thieves can be marked this way, why not potential killers and maimers?

A national 10-year experiment is worth trying. With 250,000 lives at stake, it's better that orange paint be our highway's most common color--instead of red blood.