It’s one thing to have a law on the books, and quite another to effectively enforce it.

That holds true in California and every other state, and the occasional disconnect that occurs when police officers strongly suspect that a law is being broken yet lack sufficient evidence to do anything about it can seem especially marked when it comes to driving and smartphones.

Because the act of smartphone engagement while behind the wheel is ephemeral. A cop thinks he or she has spotted a driver busily preoccupied with talking or texting, but there’s often no corroborating proof of that when the motorist has pulled over and vehemently denies that his or her eyes were on a texting keyboard rather than on the road.

California’s prohibition against hand-held phone use and texting while driving is “primary,” meaning that an officer can stop a motorist and issue a ticket for those offenses alone, not needing some other reason to stop a driver first.

But, again, there’s that sticky proof issue.

Some lawmakers in one state have obviously spent a bit of time thinking the matter through. A bill was recently introduced in New York that, if enacted as law, would allow officers to plug a device termed the “Textalyzer” into a driver’s smartphone following a car crash (the device could conceivably also be used after a driver is stopped for suspected of unlawful phone use).

The textalyzer employs technology that reveals phone texting, surfing and call history before a crash. The New York bill contemplates that officers would not need a warrant to use the device.

As a story on the tool notes, it is far away presently from being law. Moreover, it is quite likely that the bill will confront challenges from privacy groups.

Its very existence, though, indicates the growing concern of legislators and safety regulators with behind-the-wheel smartphone use by motorists. We all know how dangerous such activity is.

Although it is uncertain whether the textalyzer will ultimately gain traction in New York or elsewhere, it’s a fair assumption that enforcement officials and legislators will continue to look at developing technologies for hoped-for efficacy in identifying and eradicating reckless road behaviors.

And legions of safety-conscious and responsible drivers across the country will applaud the effort.