Mobile billboards — Guides

What to put on a billboard: designing a board that pulls

A driver gives your billboard about four seconds. In that time the board must be read, understood and remembered — which means one message, big type, one way to respond. Around 80% of a campaign's success comes down to what the board says, and it is the part most advertisers get wrong. This is the checklist we apply to every board before it prints.

The four-second rule

Everything on the board must survive being read from across four lanes of moving traffic. That single constraint decides everything else: the word count, the type size, the image, the contrast. If a passenger cannot read the whole board aloud in four seconds, it is carrying too much.

What a board that pulls contains

One message. Not your five services — the one thing you want this suburb to do. "Half-price ribs Tuesdays." "2 beds from R899k." "Applications open for 2027." A board that says everything says nothing at highway distance.

One number or one action. A phone number, a WhatsApp number, or a short web address — pick one. Two response options halve the response to each. In South Africa, a WhatsApp number is usually the strongest choice: it is how local customers already talk to businesses.

A number in the offer, where the industry allows it. "From R3 499 p/m" outsells "affordable finance". "No joining fee" outsells "great rates". Specifics are believable; adjectives are wallpaper.

Big, few words. Six to eight words of headline is the working ceiling. Type should be readable at 100 metres — if the designer has to shrink the font to fit the sentence, cut the sentence, not the font.

One strong image, if any. A single appetising dish, one vehicle, one face. For restaurants the food photo is the headline; for estate agents the face is — recognition is the product. Collages die at distance.

Contrast. Dark type on a light board or the reverse, tested in sunlight, not on a screen. Subtle brand palettes that look elegant in a boardroom disappear on a roadside.

What we flag before printing

Every board we run is reviewed against the AIDA framework — Attention, Interest, Desire, Action — before it goes to print. The patterns we flag most:

• — The logo board. A logo and a slogan with no offer and no number. It decorates the road and generates nothing.
• — The poster. Event boards carrying the full line-up, sponsors and fine print. The board's only job is date, venue, ticket line.
• — The list. Every service the business offers, in shrinking type. Pick the one this suburb searches for.
• — The clever headline. Wordplay that needs a second read. Nobody gets a second read at 60 km/h.
• — The missing suburb logic. A great board parked in the wrong place. Message and placement are one decision, not two.

We would rather flag a weak headline than print it — a reprint costs days; a weak board costs the whole campaign.

Practical spec for a trailer board

Boards are large-format landscape prints, sized to stay legible from across four lanes. Exact dimensions vary by trailer, so we send the artwork template for your assigned trailer — dimensions, bleed and safe area marked — before anything is designed. Print-ready PDF is ideal; vector files (AI, EPS, CDR) scale best; high-resolution JPEG or PNG also works. Because we print in-house, a new board is ready in 2 – 3 working days, which is how specials, phases and countdowns stay current.

We run mobile billboard campaigns across 16 suburbs in Johannesburg and greater Gauteng, and review every board's copy before printing.