The following editorial appeared Monday in the Tacoma News Tribune.

When Washington restricted the licenses of newly minted 16-year-old drivers five years ago, it joined a healthful trend.

The Legislature in 2001 made the car keys a lot tougher for 16-year-olds to come by. Gone was the old practice of issuing them standard driver’s licenses if they passed the requisite tests; instead, they could earn “intermediate licenses” with extensive adult training and safe driving records.

The licenses came with a 1 to 5 a.m. curfew on their driving hours and what amounts to a ban on joyriding with their friends. If they go a full year without a collision or a ticket, they qualify for unrestricted licenses.

Washington didn’t pioneer this policy. Other states had been passing similar laws, beginning in the mid-1990s.

It’s been clear for some time that these rules have been saving lives. Now, thanks to an extensive study done by the Johns Hopkins Bloomberg School of Public Health, we’ve got a fix on how many lives.

As it turns out, the states with the most effective restrictions – such as Washington’s – are seeing, on average, 21 percent fewer traffic fatalities among 16-year-olds than states with no restrictions. That is a huge payoff.

The chief surprise here is that the trend toward graduated driver’s licenses didn’t begin a lot earlier.

We knew long before the 1990s that inexperienced teenage drivers – especially males – are far more prone to serious accidents than almost any other demographic.

Current statistics indicate that the youngest drivers are more than three times as likely to die in crashes than 35- to 74-year-olds, the safest demographic. They are also far more likely than their elders to kill someone else on the road.

So it’s simple common sense to start 16-year-old drivers out slowly, under strict limitations, as they gain the maturity and driving experience needed to avoid collisions and other accidents.

One question the Johns Hopkins study left unanswered was whether the license restrictions actually cut the rate of teenage crashes per mile driven. It’s possible the law might be preventing fatalities merely by having 16-year-olds drive less.

But either way, fewer are dying. However they work, these laws are keepers.