Every campaign wants to add one more thing to the sign. This is the argument for not doing it.

One second, one message

A sign on a verge is read at speed, once, from an angle. It can deliver a name and sometimes an office. It cannot deliver a policy.

Each additional line takes height away from the name, so two messages usually mean neither lands.

Contrast beats colour

Legibility at distance comes from contrast between the type and the background, not from how strong the colours are.

A mid-tone background with mid-tone type looks fine on a screen and disappears outdoors.

The disclaimer has to be readable

It is a legal requirement, so setting it too small to read is not a design decision, it is a risk to the whole run.

Confirm the minimum size for your jurisdiction and approve it at actual size on the proof.

Both sides, when it matters

A sign on a verge is passed from two directions and a rally sign is photographed from behind as often as in front.

Double-siding is cheap. A blank back is the most common wasted half of a print run.