The phrase is stamped on the license plate on the 6,247, or so, registered motorcycles in Androscoggin, Oxford, and Franklin counties: “Ride Safe.” Short and sweet, these two words together are a mantra, and a caution, for everyone sitting astride a motorcycle.

Its meaning is broad. Don’t drink alcohol before riding. Don’t speed or weave through traffic. Steer clear of wet pavement, if possible, and beware loose gravel or sand. Dress appropriately. Use your turn signals. Wear, if you choose, protective headgear.

We can’t stress this last point enough. Two accidents have occurred in the past week involving riders lacking helmets: 19-year-old Stephen Richard, of Auburn, died on Interstate 95 in New Hampshire on April 21, while Bruce Mica, 63, of Paris, was hospitalized in critical condition following a crash in Paris on April 23.

One of the sure signs of spring, aside from blossoming tulips and rising mercury, is the proliferation of motorcycles of Maine’s roads. Registrations have spiked – from 27,650 in 1999 to 41,119 in 2006, according to state data – yet laws governing Maine motorcycle helmet use are unchanged.

In Maine, motorcycle passengers 15 and under, or motorcyclists riding within one year of passing a driver’s test, or carrying a learner’s permit, are compelled to wear helmets. In all cases, helmet use is strongly recommended for valid health and safety concerns, but the law can’t make riders wear one.

Not for lack of trying. Attempts to make helmet use compulsory for all ages, the situation in 20 other states, have failed before the Maine Legislature. Motorcycle advocates claim evidence supporting mandatory helmets is inconclusive, as fatalities occur equally between helmeted and non-helmeted riders.

It’s one thing to say Maine shouldn’t legislate based on the lack of facts, but quite another to avoid mentioning the preponderance of other evidence that strongly supports mandating helmets for motorcycle riders.

A 2005 study in Florida by the National Highway Transportation Safety Authority, which repealed its mandatory helmet law in 2000, found overall motorcyclist hospital admissions had risen 40 percent, and 82 percent for those suffering head injuries. The cost of treating those injuries also rose precipitously, which pushes up health care costs for us all.

Although Florida retained mandatory helmets for riders under 21, NHTSA found helmet use plummeted among those riders after the repeal, leading to a threefold increase in fatalities in that age group. Maine differs from Florida, in many ways, but the Sunshine State’s experience is still striking.

Maine needs a blanket helmet law, but the opposition is stiff. Lawmakers, instead, should focus efforts on raising Maine’s benchmark age of 15 – the lowest in the country – to 21 for mandatory helmet use. This age group is arguably most at-risk for injury, and helmet use, to encourage responsible riding, should be unquestioned.

And what “Ride Safe” is all about.