How to segment an out of home advertising target audience by journey and daypart

What to take away

Start with the journey, not the person

Place-based advertising reaches people in transit, so the journey is the unit of analysis. A commuter walking to a station at 07:40 behaves differently from the same person driving to a retail park at 14:00.

Build your first cut around purpose: commute, shopping, leisure or service errand. Then layer the time band. A segment such as "weekly grocery trip, Saturday morning, 20 minute drive" is buyable. "Women aged 25 to 44" is not, because it does not tell you which sites to book.

If you are new to this method, the England out-of-home advertising audience research guide sets out the definitions and data sources behind each step.

Check the employment base before you size anything

Employment patterns can inform daytime demand, but the Office for National Statistics (ONS) UK labour market release on people in work is a national employment indicator, not a local footfall count or an OOH audience estimate.

Use the Department for Transport's National Travel Survey to check trip-purpose and time patterns in England, and the ONS Census 2021 dataset "Method of travel to workplace" for workplace-travel context. These inform assumptions rather than measuring footfall at a particular site; Census 2021 is a pandemic-era snapshot, so do not treat it as a current commuting baseline.

Match any audio-adjacent claim, such as a drive-time radio audience used to justify a roadside format, to the latest quarterly RAJAR (Radio Joint Audience Research) listening data rather than a remembered figure.

Build the segment in four passes

A daypart is the explicit time window attached to a segment. Do not assume one set of boundaries applies across UK OOH: booking windows vary by format and media owner. For example, a weekday 07:00–09:00 station commute and a Saturday 09:00–13:00 grocery trip are planning examples, not universal booking bands.

Route is the UK OOH audience measurement currency; use its audience estimates to assess the reach and frequency of eligible sites and formats. Outsmart is the UK OOH industry body. Use these measurement inputs to size media opportunities, and do not present them as a direct count of a particular journey-purpose segment unless the underlying measurement supports that claim.

Four passes is usually enough. A fifth often produces a segment too narrow to buy. To understand who else competes for the same audience, the out-of-home advertising competitor research method maps rival advertisers against the same sites and dayparts.

Before and after: a worked comparison

The table below shows a typical rebuild. The figures are illustrative examples, not measured results.

The narrower segments reach fewer people but map onto inventory you can book. That is the trade you are making.

Check compliance before you activate

Where a segment involves personal data, such as addressable screens, mobile retargeting or email follow-up, assess the applicable UK GDPR, PECR and Data Protection Act 2018 obligations. The Information Commissioner's Office (ICO) publishes its Direct marketing checklist, covering matters including consent, legitimate interests and record-keeping; use it where the activity is direct marketing, alongside any broader privacy assessment needed.

Read it before you brief a media owner, not after. Segments built on inferred location data are the ones most likely to attract a complaint.

Document what you rejected

Keep a short note on each segment you discarded and why. This matters when a client asks in month three why the audience shrank. It also stops the same weak segment being rebuilt next quarter by someone who was not in the room.

Store the note alongside the campaign plan, with the data source and its date. If a figure came from a census release or an employment bulletin, name it. Undated numbers are the main reason audience claims fall apart in a review.

Common questions

How many segments should one campaign use?

Two or three is usually workable. More than that and the budget spread across each segment becomes too thin to produce a readable result.

Can I use the same segments across England, Scotland and Wales?

No. Travel patterns, employment mix and available inventory differ, so rebuild the segment for each nation rather than copying an England set north or west.

Do I need new research for every campaign?

Not always. Reuse the segment logic, but refresh any figure that carries a date, particularly employment and listening data.

What if the client insists on a broad age and gender segment?

Run it alongside a journey-based segment in the same campaign. Comparing the two gives the client evidence for the next planning round.