How Many People Actually Pass Your Billboard? Count the Audience by the Hour

Outdoor advertising is sold on traffic. The board on the corner is worth what it is because of the people and cars that pass it. But the number on the rate card is often a yearly estimate for the whole road, and two things it can’t tell you matter a lot:

• Which direction faces your ad. A board facing northbound traffic is invisible to southbound drivers.
• When. A digital screen that rotates ads by the hour is worth very different amounts at 8 am and at 3 am.

You can count both yourself.

What to count

Vehicles in the direction that faces the board. That’s the audience. Count both directions anyway: the other side is useful for the board across the street.

Pedestrians and cyclists, separately. On a shopping street or near a station, people on foot pass slowly and close, and a bus shelter ad is mostly seen by people standing next to it. They’re a different audience from drivers, so keep them apart.

By the hour. A digital screen sells slots. Knowing which hours carry the most traffic tells an advertiser which slots to buy, and a screen owner which slots to price higher.

Counting with a camera

A camera aimed at the road in front of the board, plus a tool that counts what crosses a line, does this around the clock. I built Passerby, a working example of such a tool, and you can try it on live public traffic cameras right now:

1. Open Passerby and pick a camera. The I-405 quick picks show a busy freeway; Crenshaw Blvd and Manhattan Beach Blvd show city intersections.
2. Draw the counting line across the lanes that face your imaginary board.
3. Watch the cards: vehicles, motorcycles, bicycles and pedestrians, each split by direction.
4. Switch the chart to 15 min and leave it running, then Download CSV for the counts by interval.

For a real board, a camera mounted near the structure counts for weeks, and the report shows each hour of each day in each direction.

Using the numbers

• For advertisers: compare what you counted with what you were sold, and buy the hours that carry your audience.
• For board and screen owners: price slots by measured traffic, show buyers real numbers for this board, and spot when a road change or a new development moved the traffic.
• For campaigns: count before, during and after, at the same hours, and set foot traffic at a store near the board against the sales.

What it doesn’t measure

A count is everyone who passed, not everyone who looked. It measures the opportunity to see the ad, at your board, instead of an estimate for the whole road.

Counts from a camera are estimates: night, rain, glare and vehicles hiding behind trucks lower them, and a camera too far from the road misses small vehicles. Mount it close, and compare hours and directions rather than reading too much into a single number.

Try it

Open Passerby and count a live road for a few minutes.

Own boards or screens, or buy outdoor media? Tell me what you’d like to count.