Among the common-sense rules of ambulation, this one might be the most foundational: Somewhere midway between Point A and Point B, it’s good to pause, evaluate one’s progress and adjust course if necessary.

This is especially true when the course you happen to be navigating is Butler’s streets after 4:30 p.m. in December. The landscape has more than its share of dark corners.

Eight years ago, the federal Department of Justice finalized regulations establishing standards for motorized wheelchairs, mobility scooters and other ambulatory aids under the Americans with Disabilities Act. Since these regulations went into effect, Medicare-subsidized motorized chairs and scooters have proliferated, much to the benefit of disabled people who have found new levels of independence and productivity as a result.

The emphasis was on mobility, comfort, affordability and ease of use. Brand names like Hoveround, Pride Jazzy and Drive Medical have become part of the everyday vernacular — and their users can be seen zipping along the streets and sidewalks all over town.

The worry, however, is that there are times and seasons when the scooters and their riders can’t be so clearly seen — especially in wintertime, when the days grow short, nights come early and snowbanks accumulate.

The ADA regulations do nothing to address issues of visibility. While bicycles must have a certain amount of reflective surface material and lighting for nighttime use, there are no such provisions for mobility scooters or motorized wheelchairs.

In addition, many of these devices operate in silence. On a dark street or sidewalk, an approaching scooter often is as hard to hear as it is to see.

It’s not a secret that scooter operators have been observed in Butler’s streets when they themselves probably would prefer to stick to the sidewalks. But let’s face it: Some residential sidewalks are not maintained to optimal standards, even without ice or snow accumulation.

It seems there are two inevitabilities waiting to happen.

The first is that someone in a scooter is going to be run over by a vehicle. The second is that reflective material, or lighting, or helmets or other protective gear will be required by state regulation for anyone operating a scooter or motorized wheelchair in a public right of way. These things tend to occur according to a cause-and-effect pattern — somebody acts after somebody gets hurt, or killed.

We don’t have to wait for that to happen. As a community, we can commit to a few objectives:

Maintain your sidewalks and keep them passable, especially during winter snowfall.

Drive with extreme caution, especially during twilight hours. Drive defensively, anticipate the unexpected.

If you ride a chair or scooter and anticipated being out after dark, wear light-colored clothing that makes you easy to see at night. This is the same thing that’s asked of bicyclists, joggers and walkers who share the right of way with motorists. It’s not an infringement of anyone’s rights; rather, it’s a common courtesy — not to mention a potential life-saver.