A chain is only as strong as its weakest link.

That classic bit of folk wisdom might well be applied to plans for keeping people safe from the coronavirus. In the school reopening plans that Ridgefield’s school administration and Board of Education are diligently working on, the weakest link may well be school bus rides and bus stops.

The survey school authorities sent out is telling. In responses from more than 2,000 parents, 81 percent said they intended to send their children back for in-school classes in the fall, but only 36 said they would put their kids on school buses running at full capacity.

The parents know. They rode the big yellow buses themselves, most of them. So while four-fifths of Ridgefield parents were willing to send their kids back to school buildings, nearly two thirds were dubious of putting kids on packed school buses.

The buses have always been the wild west of the school day, a zone of lax enforcement between the more tightly monitored world inside the school buildings, and the parent-dominated security of home. Traditionally, the only adult on a school bus is the driver — and bus drivers, rightly, are focused on the road, traffic, safety.

On buses the kids — 40 to 60 of them, often a mix of ages and physical sizes — are confined together for long boring rides, with no close supervision. Bullying and other misbehavior can run rampant. It’s not the drivers’ fault — they’re busy driving, and driving is what both parents and school officials should want them paying attention to.

Bus stops are another concern — part of that low-supervision netherworld between school and home.

In the reopening plan that Ridgefiled school officials continue to refine, concerns about school buses do get attention. Among the larger items in the list of new costs anticipated is $105,000 for “bus monitors.”

Good. Adding bus monitors is sold thinking — even if it, inevitably, has a substantial price tag. The monitors are absolutely necessary. With the virus around, it’s not just a matter of keeping kids from getting crazy — someone needs to make sure they’re all wearing their masks.

In addition to their very sensible plan to put monitors on buses, school officials should also look into increasing the number of buses and bus runs so that fewer children are on each bus, the kids aren’t so closely packed together, and the rides are shorter.

As for bus stops, the schools can’t be expected to provide supervision on the side of the road, before and after school hours. But school officials should recognize bus stops are a problem and encourage or even consider helping set up some system — a website, email-chains, something — to ease communication among neighborhood parents and assure that they are engaged and organized enough to always have adults with the kids at bus stops. Maybe building principals could work with PTAs to organize something.

And parents who have the time should consider offering to serve as bus monitors or bus stop supervisors. Somebody has to do it, who better than parents?

School authorities have a very full plate already — as do parents. But school buses and bus stops demand a share of attention. The old fashioned ‘He put gum in my hair!’ type misbehavior long common on buses is raised to a higher level of concern with the arrival of the highly contagious and deadly coronavirus.