HONOLULU - Driving while drug-impaired is a growing problem, according to state and federal transportation agencies- but how do you legally define drug impairment? That's what a Senate bill looks to firm up.

Police can arrest people for driving under the influence of drugs, but only if they test positive for a certain set of drugs as defined by state law. Mothers Against Drunk Driving (MADD) founder Carol McNamee explains, "It's confined to the schedule of drugs in our statutes."

That's too narrow, says McNamee. The Stanford University-educated chemist notes, "So many new drugs are being synthesized and rapidly," that there are more street drugs than the law can keep up with.

MADD provided input on a bill now in the state Senate that would make it easier to arrest and prosecute drugged drivers. Senate bill 641 would "expand the definition of drug," McNamee says.

In her fight against drugged-driving, which she fears is on the rise, she also hopes the state will build a drug testing lab. "When blood and urine are tested to identify drugs, most of the samples are send to the mainland which is expensive, costly, and time consuming," she says.

McNamee says MADD is still concerned about drunk driving, but it's now working on keeping our roads safe from drugged drivers. A Senate judiciary committee will have a public decision making on Senate bill 641 on Thursday at 9 a.m. in conference room 016.