A sign in the road is a liability, not an inconvenience. It is also entirely preventable, and the fix is a design choice rather than an accessory.

Why the classic shape fails

A folded A-frame presents two large flat faces to the wind and stands on a narrow footprint. Past a certain gust it does one of two things: folds shut, or tips. Neither is recoverable without somebody going outside.

Adding weight to the feet helps a little and adds a trip hazard. It does not change the geometry.

What a spring base does differently

A water-base sign mounts the panel on a heavy spring above a fillable base. A gust pushes the panel over; the spring and the ballast bring it back upright. The sign moves instead of falling, which is exactly what you want.

It also cannot fold shut, because there is nothing to fold. On an exposed frontage this is the only design that reliably survives a windy week.

Fill it properly

Sand is heavier than water for the same volume and does not freeze. Water is easier to fill and empty on site, but a fully filled base can split in a hard frost — part-fill it through winter, or switch to sand.

An empty base is worse than no sign at all: it looks solid and behaves like a sail.

Bring it in, and know when

Whatever the design, there is a wind speed at which the sign should come inside. Decide it in advance and tell the staff who open and close, because in the moment there is always a reason to leave it out.

A sign that spends an occasional afternoon indoors will outlast three that did not.