Cameras on public transit, from buses to light rail, may be nothing new, but their number is increasing. In Portland, for example, new buses include eight cameras each, one more than on the next most recent purchases. Not only do the cameras create a video record; they’re equipped to produce an audio record of life on a bus as well.

That newest camera on Portland’s buses has caused the metropolitan area’s transit agency, TriMet, more than a few headaches.

Drivers don’t like it.

The new cameras are aimed directly at them, recording everything drivers say and do during the course of a work shift. The resulting record could be used for all manner of things, from determining if an accident were a driver’s fault to discovering if the driver treated riders with a modicum of respect.

Too, the visual and audio recordings go on full time, including periods when drivers are taking a scheduled break from work. Many spend that time on their buses, doing everything from adjusting their underwear to making doctor appointments on their cellphones. The agency’s use of the newest cameras and the audio recordings on all cameras should be subject to negotiation between the agency and its union, the union says.

Last year, the union Amalgamated Transit Union 757 took its complaint to the state’s Labor Relations Board, which ruled on it this spring, giving both sides some of what they want.

The so-called eighth camera stays, Administrative Law Judge B. Carlton Grew said. But TriMet must negotiate on use of the audio equipment and the use of both cameras and audio during drivers’ break periods.

The cameras do have their place. One on a bus in San Antonio caught a driver texting — and crashing — while on the job. They can also clear a driver accused of behaving improperly.

At the same time, drivers should be allowed to take their breaks in peace, or at least give up that right for themselves rather than having it simply taken away. The labor board’s ruling strikes a reasonable balance between safety and privacy, it seems to us.