...and again nobody is looking here
Posters operate according to different principles than, say, radio or TV
Posters are subject to different laws of effect than radio or TV... and again, nobody is looking hereBy Wolfgang KoschnickThe third and final article on the subject of poster research is about the fundamentals: Research methods with or without technical measuring devices are still controversial. Poster sites are perceived by "everyone". Impact research must therefore be based on a mass medium without a defined target audience.
For poster researchers, the real problems start where the problems of other media researchers have already been solved. And that is why poster research has to answer questions that do not exist in "normal" media research. This has to do with the special features of outdoor advertising:
The "normal" advertising media have "normal" users (readers, TV viewers, radio listeners, moviegoers) who also come into contact with advertising during their media consumption. This is not the case with posters. The advertising medium "billboard" per se has no audience at all. Nobody uses a billboard if there is no poster on it. The advertising medium is worth nothing for advertising if there is no advertising medium. With "normal" advertising media, the opposite is the case. In poster research, therefore, no evidence whatsoever can be gained for the use of the advertising medium "poster" from the use of the advertising medium "billboard".
A daily newspaper is the same paper wherever it is published. A magazine is the same everywhere, regardless of whether you read it in Zurich, Lucerne, Bern or Basel. The program of a radio or television station is received by every listener and every viewer in the same way as by every other listener or viewer. The similarity of the advertising media is their characteristic. That is why their audiences are relatively easy to measure and compare.
Diversity as a basic characteristic
It's different with posters. One poster site is located in the middle of the hustle and bustle of Zurich Airport. Hundreds of thousands of people pass by there every day. The other is in a small town where there isn't much going on, but a few thousand people still pass by.
No two poster sites are the same. The diversity of advertising media is the hallmark of outdoor advertising. However, the same values are needed for the advertising medium "poster site" as for any other advertising medium. Above all, you need contacts and, on the basis of the selected contact definition, reach and contact frequencies that are collected at the same level.
But how can this be done when the advertising medium "billboard" is so radically different from all other advertising media? The answer is as simple as the solution is difficult: by agreeing on a series of conventions and compromises. This is how media research works for all genres. There are no flawless solutions that meet all the purists' requirements in commercial research anyway.
Equality of the poster site with other media
In poster research, too, we must therefore first agree on a key concept of media research: the contact definition. It is used to isolate all those for whom it is absolutely clear that they are guaranteed not to see or hear an advertisement or commercial. All others have a high or low chance of contact, depending on the situation. For print media, for example, the chance of contact with an advertisement in Switzerland is defined as anyone who states in a survey that they have "read or leafed through" a magazine XY.
A contact definition must therefore be found for poster research that can exist at the same measurement level as the contact definition used in readership research. Which definition of contact fulfills this purpose? Is it enough if someone stands two hundred meters in front of a billboard? Or does it have to be one hundred meters? Or even just twenty? Is a five-second contact better than one that lasts just half a second? Or is the duration of contact irrelevant?
Different definitions of the term contact
Whenever the term "poster research" is used lightly, what is really meant is "billboard research". This is because it is exclusively about researching the communication performance of the advertising medium "billboard" in intermedia competition. And the central question here is: How do the various poster sites differ from one another in terms of the advertising media contacts they generate?
Some differences are so obvious that you don't have to think much about them. Of course, a huge illuminated surface covering the whole of Times Square is much easier to see than a small piece of paper stuck to a wall somewhere on a dark side street. But does a billboard that faces the flow of traffic really communicate more effectively than one that is parallel to the traffic and that you might just be able to see out of the far corner of your eye as you drive past?
These detailed questions deal with different aspects of one and the same problem: How do you define "contact" in poster research? Various approaches have been found in practice. The simplest approach is taken by Plakatwertung Österreich (PWÖ). It says: If someone passes a poster at a distance of less than 80 meters and at an angle of more than 30 degrees, they have made contact. Period. It doesn't matter whether a person walking or driving past it actually has this contact or not.
Poster research models from simple to sophisticated
You can make it that simple. The definition of contact in readership or television research is no more complicated than that. And the Austrians have said to themselves: it doesn't really matter which definition of contact you use. The main thing is that the same standard is applied to all poster sites throughout the country.
Other research projects have made things a little more difficult for themselves and found an empirically supported definition of contact. The German Plakatmediaanalyse (PMA) has chosen the narrowest definition with its "poster survey based on remembered paths" in a personal interview with memory aids. As already shown in the second installment of this article series (WW 7/01), it has even been shown that the empirical data collected by the PMA is incorrect and needs to be corrected.
That's the crux of the matter anyway. Empirical findings often emerge that cannot be objectively true. Swiss private radio stations sometimes make a joke of it and ask passers-by how they voted on this or that issue in the last referendum. However, they ask about an issue that was not voted on at all. And lo and behold: in their answers, people nevertheless provide very precise information about their voting behavior.
As an aside, reader research has not empirically tested its concept of contact any more than any other advertising medium. Why should it? So why should the poor poster researchers be any more Catholic than the Pope? The concept of contact has been defined by consensus everywhere in media research. And the same consideration was always the basis worldwide: the only thing to be examined is how the concept of contact is to be defined. Should it be completely "hard" or rather "soft"? A soft definition of contact, in which even the gentlest hint of contact is included, is particularly popular with providers of contact points. This allows them to show that their sites generate a particularly high number of hard-hitting contacts and achieve a particularly high reach. They can then charge higher prices for this. Advertisers and their agencies naturally prefer a hard contact definition. After all, they have to pay for every contact. For really "hard" contacts, they can still see that. But for the really flabby ones, they would prefer not to pay anything at all.
Contact duration is often overestimated in poster research
Between the two extremes of PWÖ and PMA lies the whole variety of realistic poster research in many countries: in the UK, eye-tracking cameras have been used to record how passers-by let their gaze wander in the vicinity of poster sites; after all, it is quite clear that a passer-by who walks three meters past a poster site has a higher chance of contact than someone who drives past at top speed and possibly on the opposite side of the road in a car and looks neither to the right nor to the left.
The same applies to the influence of the number of attachment points. It is possible that contact is affected if an attachment point stands alone somewhere in a wide open space or in a group with five others. But it is impossible to know exactly what effect this will have. It is possible that the passers-by have contact with every single one of them. But they may not. It's impossible to know without empirical research.
However, the importance of contact duration is often overestimated: whether someone strolls past a poster site in five minutes or rushes past in just five seconds. The first person has 300 seconds of contact, sixty times as much as the second. But the five seconds are enough to be reached by the advertising message on the poster.
However, the following facts need to be clarified: What duration is sufficient for contact? The average attention time for advertisements is only 1.7 seconds. In the case of posters, it should be possible to assume an even shorter attention time. This can probably only be determined with the help of an empirical study.
The contact definition determines under what circumstances and under what conditions how many people come into contact with advertising messages on billboards. If the sole task of poster research were to investigate the communication performance of the billboard as an advertising medium, one could be satisfied with the evaluation of individual sites.
The characteristics of poster sites that are conducive to generating poster contacts must be identified and quantified for each individual site. This would provide precise data on the communication performance of all outdoor advertising media. That's all you really need to evaluate the communication performance of the advertising medium.
However, if you also want to find out which people have contact with attack sites - i.e. if you want to collect personal data about contact with attack sites - you have to collect this additional data separately.
Young people are mobile
and has a lot of money
One can argue about how high - or low - the insight value of personal data on poster usage is. It can even be argued that its insight value - and in media planning this means its relevance to planning - is rather low.
Why? Only people who are out of the house have contact with poster sites. And who is that? Pretty much everyone. Everyone is outside from time to time. Only the very old and the very young - neither of whom are particularly relevant to the communication performance of advertising media - spend less time outdoors. This amounts to a tautological definition: the mobile are outside more often than the immobile. There is actually no need to laboriously investigate this.
All poster research worldwide confirms the same truism: posters primarily appeal to mobile sections of the population. And in the demographic characteristics associated with mobility - more likely to be male, more likely to be young, more likely to have a higher household income and a higher level of education - higher reach and GRP values can therefore be achieved. Do we really need laborious research - which, to make matters worse, is also really expensive - to bring such truisms to light again and again?
The PMA in Germany goes to great lengths to differentiate personal data according to the three media large format, full-page and city light poster (CLP). And what was the result? There are no significant target group differences between the three advertising media types. The poster reaches the same people everywhere, regardless of the form it takes (the
CLP achieve higher performance values in cities, but this is exclusively due to the fact that they do not occur at all in the countryside).
The whole event serves to collect target group-related data. And of all things, it does not provide any differentiation when it comes to target group-oriented information. And it does not do so because it cannot do so. The target audience for outdoor advertising is the same everywhere.
Out-of-home advertising media are, after all, a classic mass medium without a target group. In principle, their audience is "everyone". This is precisely what distinguishes it from many other advertising media: a magazine for hobby gardeners or for goldfish breeders, as well as a men's magazine or a women's magazine, is simply an ideal advertising medium for messages aimed at precisely defined target groups. This is precisely what outdoor advertising media are not.
However, if you still want to collect personal data, it will definitely be a rather complicated matter. The international poster research community has come up with a lot of collection models to obtain personal data. The only thing that is fairly certain is that the huge effort involved hardly justifies the data yield. The big mountain is circling and yet only a few measly data mice have been born.
Technical devices are not beyond all doubt
In principle, three different methods can be used: (1) surveys, (2) observations (technical measurements) and (3) the use of existing traffic count data. None of these methods has so far led to really convincing results.
Surveys in the past have shown this in many cases: People give false information about whether and how they see posters. They often cannot reliably remember whether they have actually had contact with an outdoor advertising site.
The great advantage of surveys is precisely the almost limitless flexibility of the instruments. If overly restrictive questions lead to distortions, the questions can be varied until better results are obtained.
The instrument of the survey has the undeniable advantage that it is extremely cost-effective. If one question measures incorrectly, then you just use another one. If, on the other hand, you use technical equipment and then discover that the expensive devices do not measure properly, you are stuck with the high costs.
The trend in the more modern methods of mobility analysis, as in media research in general, is clearly moving towards observation through technical measurement. There are two main reasons for this.
Firstly: Observation by technical measurement is a procedure at the same level of accuracy as that practiced by audience research with Telecontrol or, more recently, listener research with Radiocontrol. The real problems with this method only arise beyond the measuring accuracy of these devices. However, this has not yet affected their acceptance.
Secondly, technical measurement using methods such as the Geographical Positioning System (GPS) has had little experience - positive or negative - in the field of poster research. In navigation, however, it has proven its worth. Today, the technology is only used in the British Postar research model. So far, virtually nothing is known about the pitfalls of the system in media research.
The procedure is easy to understand. Each interviewee is given a GPS device, which they carry with them wherever they go. It can be attached to their clothing or in their car. The navigation system determines his or her location or movements at all times and can thus determine when a person makes contact with posters, as the locations of all poster sites are already known.
However, we can already say that there are two major problem areas with GPS and other technical measurement methods: Firstly, they do not work in large buildings such as train stations and similar buildings. These are, after all, the most frequented and contact-intensive locations in all outdoor advertising. And secondly, there are often problems in urban canyons, i.e. wherever the walls of a building prevent the GPS device from making contact with its satellites. And house walls are found in cities, where outdoor advertising is particularly effective.
Traffic count data is more reliable and cheaper
Unfortunately, the more precise the measurement needs to be, the greater the problem. If you only need to determine a location approximately and with an accuracy of a few hundred meters, it is still reasonably easy to do. But if you want to be more precise, then every house, every tree and every shrub will interfere ...
Years ago, the German Outdoor Advertising Association (FAW) attempted to use data from spatial planning for outdoor advertising. To this end, the "Braunschweig model for determining traffic frequencies" was developed using data from traffic counts. In contrast, other methods work with frequency samples that are collected directly at the poster sites and are therefore independent of the availability of suitable traffic count data from public authorities. Experience has shown that traffic count data available for individual cities varies greatly in terms of quality, completeness and timeliness.
The practical benefits of the Dutch Buitenreclame also result primarily from the fortunate circumstance that the Dutch have access to data from the official traffic counts of the Dutch Spatial Planning and Surveying Agency for mobility analysis.
It collects relevant data on the traffic behavior of the Dutch with 120000 respondents every year. From these counts, the start and end points of the journeys made are known - but not the journey itself.
As the census data on the "route choice behavior" of the population cannot be used directly for
The market research institute Intomart developed a model that can be used for poster research. It is based on a sample of 7000 people. For the people in
of this sample, routes are calculated using a complicated procedure, which they are likely to take and assuming that they differ from
The traffic will choose the "easiest" route from a certain starting point. In simpler terms, the traffic flows from the official traffic counts are used to calculate probabilities for poster site contacts. These routes are then transferred to a digital map.
There is actually no greater ideal than being able to use data from a traffic census or a population census. Admittedly, these were not collected specifically for the very special needs of poster research. But they can be used for this purpose without much hesitation. And they are an incredibly cost-effective way of collecting data.
For poster researchers, the real problems start where the problems of other media researchers have already been solved. And that is why poster research has to answer questions that do not exist in "normal" media research. This has to do with the special features of outdoor advertising:
The "normal" advertising media have "normal" users (readers, TV viewers, radio listeners, moviegoers) who also come into contact with advertising during their media consumption. This is not the case with posters. The advertising medium "billboard" per se has no audience at all. Nobody uses a billboard if there is no poster on it. The advertising medium is worth nothing for advertising if there is no advertising medium. With "normal" advertising media, the opposite is the case. In poster research, therefore, no evidence whatsoever can be gained for the use of the advertising medium "poster" from the use of the advertising medium "billboard".
A daily newspaper is the same paper wherever it is published. A magazine is the same everywhere, regardless of whether you read it in Zurich, Lucerne, Bern or Basel. The program of a radio or television station is received by every listener and every viewer in the same way as by every other listener or viewer. The similarity of the advertising media is their characteristic. That is why their audiences are relatively easy to measure and compare.
Diversity as a basic characteristic
It's different with posters. One poster site is located in the middle of the hustle and bustle of Zurich Airport. Hundreds of thousands of people pass by there every day. The other is in a small town where there isn't much going on, but a few thousand people still pass by.
No two poster sites are the same. The diversity of advertising media is the hallmark of outdoor advertising. However, the same values are needed for the advertising medium "poster site" as for any other advertising medium. Above all, you need contacts and, on the basis of the selected contact definition, reach and contact frequencies that are collected at the same level.
But how can this be done when the advertising medium "billboard" is so radically different from all other advertising media? The answer is as simple as the solution is difficult: by agreeing on a series of conventions and compromises. This is how media research works for all genres. There are no flawless solutions that meet all the purists' requirements in commercial research anyway.
Equality of the poster site with other media
In poster research, too, we must therefore first agree on a key concept of media research: the contact definition. It is used to isolate all those for whom it is absolutely clear that they are guaranteed not to see or hear an advertisement or commercial. All others have a high or low chance of contact, depending on the situation. For print media, for example, the chance of contact with an advertisement in Switzerland is defined as anyone who states in a survey that they have "read or leafed through" a magazine XY.
A contact definition must therefore be found for poster research that can exist at the same measurement level as the contact definition used in readership research. Which definition of contact fulfills this purpose? Is it enough if someone stands two hundred meters in front of a billboard? Or does it have to be one hundred meters? Or even just twenty? Is a five-second contact better than one that lasts just half a second? Or is the duration of contact irrelevant?
Different definitions of the term contact
Whenever the term "poster research" is used lightly, what is really meant is "billboard research". This is because it is exclusively about researching the communication performance of the advertising medium "billboard" in intermedia competition. And the central question here is: How do the various poster sites differ from one another in terms of the advertising media contacts they generate?
Some differences are so obvious that you don't have to think much about them. Of course, a huge illuminated surface covering the whole of Times Square is much easier to see than a small piece of paper stuck to a wall somewhere on a dark side street. But does a billboard that faces the flow of traffic really communicate more effectively than one that is parallel to the traffic and that you might just be able to see out of the far corner of your eye as you drive past?
These detailed questions deal with different aspects of one and the same problem: How do you define "contact" in poster research? Various approaches have been found in practice. The simplest approach is taken by Plakatwertung Österreich (PWÖ). It says: If someone passes a poster at a distance of less than 80 meters and at an angle of more than 30 degrees, they have made contact. Period. It doesn't matter whether a person walking or driving past it actually has this contact or not.
Poster research models from simple to sophisticated
You can make it that simple. The definition of contact in readership or television research is no more complicated than that. And the Austrians have said to themselves: it doesn't really matter which definition of contact you use. The main thing is that the same standard is applied to all poster sites throughout the country.
Other research projects have made things a little more difficult for themselves and found an empirically supported definition of contact. The German Plakatmediaanalyse (PMA) has chosen the narrowest definition with its "poster survey based on remembered paths" in a personal interview with memory aids. As already shown in the second installment of this article series (WW 7/01), it has even been shown that the empirical data collected by the PMA is incorrect and needs to be corrected.
That's the crux of the matter anyway. Empirical findings often emerge that cannot be objectively true. Swiss private radio stations sometimes make a joke of it and ask passers-by how they voted on this or that issue in the last referendum. However, they ask about an issue that was not voted on at all. And lo and behold: in their answers, people nevertheless provide very precise information about their voting behavior.
As an aside, reader research has not empirically tested its concept of contact any more than any other advertising medium. Why should it? So why should the poor poster researchers be any more Catholic than the Pope? The concept of contact has been defined by consensus everywhere in media research. And the same consideration was always the basis worldwide: the only thing to be examined is how the concept of contact is to be defined. Should it be completely "hard" or rather "soft"? A soft definition of contact, in which even the gentlest hint of contact is included, is particularly popular with providers of contact points. This allows them to show that their sites generate a particularly high number of hard-hitting contacts and achieve a particularly high reach. They can then charge higher prices for this. Advertisers and their agencies naturally prefer a hard contact definition. After all, they have to pay for every contact. For really "hard" contacts, they can still see that. But for the really flabby ones, they would prefer not to pay anything at all.
Contact duration is often overestimated in poster research
Between the two extremes of PWÖ and PMA lies the whole variety of realistic poster research in many countries: in the UK, eye-tracking cameras have been used to record how passers-by let their gaze wander in the vicinity of poster sites; after all, it is quite clear that a passer-by who walks three meters past a poster site has a higher chance of contact than someone who drives past at top speed and possibly on the opposite side of the road in a car and looks neither to the right nor to the left.
The same applies to the influence of the number of attachment points. It is possible that contact is affected if an attachment point stands alone somewhere in a wide open space or in a group with five others. But it is impossible to know exactly what effect this will have. It is possible that the passers-by have contact with every single one of them. But they may not. It's impossible to know without empirical research.
However, the importance of contact duration is often overestimated: whether someone strolls past a poster site in five minutes or rushes past in just five seconds. The first person has 300 seconds of contact, sixty times as much as the second. But the five seconds are enough to be reached by the advertising message on the poster.
However, the following facts need to be clarified: What duration is sufficient for contact? The average attention time for advertisements is only 1.7 seconds. In the case of posters, it should be possible to assume an even shorter attention time. This can probably only be determined with the help of an empirical study.
The contact definition determines under what circumstances and under what conditions how many people come into contact with advertising messages on billboards. If the sole task of poster research were to investigate the communication performance of the billboard as an advertising medium, one could be satisfied with the evaluation of individual sites.
The characteristics of poster sites that are conducive to generating poster contacts must be identified and quantified for each individual site. This would provide precise data on the communication performance of all outdoor advertising media. That's all you really need to evaluate the communication performance of the advertising medium.
However, if you also want to find out which people have contact with attack sites - i.e. if you want to collect personal data about contact with attack sites - you have to collect this additional data separately.
Young people are mobile
and has a lot of money
One can argue about how high - or low - the insight value of personal data on poster usage is. It can even be argued that its insight value - and in media planning this means its relevance to planning - is rather low.
Why? Only people who are out of the house have contact with poster sites. And who is that? Pretty much everyone. Everyone is outside from time to time. Only the very old and the very young - neither of whom are particularly relevant to the communication performance of advertising media - spend less time outdoors. This amounts to a tautological definition: the mobile are outside more often than the immobile. There is actually no need to laboriously investigate this.
All poster research worldwide confirms the same truism: posters primarily appeal to mobile sections of the population. And in the demographic characteristics associated with mobility - more likely to be male, more likely to be young, more likely to have a higher household income and a higher level of education - higher reach and GRP values can therefore be achieved. Do we really need laborious research - which, to make matters worse, is also really expensive - to bring such truisms to light again and again?
The PMA in Germany goes to great lengths to differentiate personal data according to the three media large format, full-page and city light poster (CLP). And what was the result? There are no significant target group differences between the three advertising media types. The poster reaches the same people everywhere, regardless of the form it takes (the
CLP achieve higher performance values in cities, but this is exclusively due to the fact that they do not occur at all in the countryside).
The whole event serves to collect target group-related data. And of all things, it does not provide any differentiation when it comes to target group-oriented information. And it does not do so because it cannot do so. The target audience for outdoor advertising is the same everywhere.
Out-of-home advertising media are, after all, a classic mass medium without a target group. In principle, their audience is "everyone". This is precisely what distinguishes it from many other advertising media: a magazine for hobby gardeners or for goldfish breeders, as well as a men's magazine or a women's magazine, is simply an ideal advertising medium for messages aimed at precisely defined target groups. This is precisely what outdoor advertising media are not.
However, if you still want to collect personal data, it will definitely be a rather complicated matter. The international poster research community has come up with a lot of collection models to obtain personal data. The only thing that is fairly certain is that the huge effort involved hardly justifies the data yield. The big mountain is circling and yet only a few measly data mice have been born.
Technical devices are not beyond all doubt
In principle, three different methods can be used: (1) surveys, (2) observations (technical measurements) and (3) the use of existing traffic count data. None of these methods has so far led to really convincing results.
Surveys in the past have shown this in many cases: People give false information about whether and how they see posters. They often cannot reliably remember whether they have actually had contact with an outdoor advertising site.
The great advantage of surveys is precisely the almost limitless flexibility of the instruments. If overly restrictive questions lead to distortions, the questions can be varied until better results are obtained.
The instrument of the survey has the undeniable advantage that it is extremely cost-effective. If one question measures incorrectly, then you just use another one. If, on the other hand, you use technical equipment and then discover that the expensive devices do not measure properly, you are stuck with the high costs.
The trend in the more modern methods of mobility analysis, as in media research in general, is clearly moving towards observation through technical measurement. There are two main reasons for this.
Firstly: Observation by technical measurement is a procedure at the same level of accuracy as that practiced by audience research with Telecontrol or, more recently, listener research with Radiocontrol. The real problems with this method only arise beyond the measuring accuracy of these devices. However, this has not yet affected their acceptance.
Secondly, technical measurement using methods such as the Geographical Positioning System (GPS) has had little experience - positive or negative - in the field of poster research. In navigation, however, it has proven its worth. Today, the technology is only used in the British Postar research model. So far, virtually nothing is known about the pitfalls of the system in media research.
The procedure is easy to understand. Each interviewee is given a GPS device, which they carry with them wherever they go. It can be attached to their clothing or in their car. The navigation system determines his or her location or movements at all times and can thus determine when a person makes contact with posters, as the locations of all poster sites are already known.
However, we can already say that there are two major problem areas with GPS and other technical measurement methods: Firstly, they do not work in large buildings such as train stations and similar buildings. These are, after all, the most frequented and contact-intensive locations in all outdoor advertising. And secondly, there are often problems in urban canyons, i.e. wherever the walls of a building prevent the GPS device from making contact with its satellites. And house walls are found in cities, where outdoor advertising is particularly effective.
Traffic count data is more reliable and cheaper
Unfortunately, the more precise the measurement needs to be, the greater the problem. If you only need to determine a location approximately and with an accuracy of a few hundred meters, it is still reasonably easy to do. But if you want to be more precise, then every house, every tree and every shrub will interfere ...
Years ago, the German Outdoor Advertising Association (FAW) attempted to use data from spatial planning for outdoor advertising. To this end, the "Braunschweig model for determining traffic frequencies" was developed using data from traffic counts. In contrast, other methods work with frequency samples that are collected directly at the poster sites and are therefore independent of the availability of suitable traffic count data from public authorities. Experience has shown that traffic count data available for individual cities varies greatly in terms of quality, completeness and timeliness.
The practical benefits of the Dutch Buitenreclame also result primarily from the fortunate circumstance that the Dutch have access to data from the official traffic counts of the Dutch Spatial Planning and Surveying Agency for mobility analysis.
It collects relevant data on the traffic behavior of the Dutch with 120000 respondents every year. From these counts, the start and end points of the journeys made are known - but not the journey itself.
As the census data on the "route choice behavior" of the population cannot be used directly for
The market research institute Intomart developed a model that can be used for poster research. It is based on a sample of 7000 people. For the people in
of this sample, routes are calculated using a complicated procedure, which they are likely to take and assuming that they differ from
The traffic will choose the "easiest" route from a certain starting point. In simpler terms, the traffic flows from the official traffic counts are used to calculate probabilities for poster site contacts. These routes are then transferred to a digital map.
There is actually no greater ideal than being able to use data from a traffic census or a population census. Admittedly, these were not collected specifically for the very special needs of poster research. But they can be used for this purpose without much hesitation. And they are an incredibly cost-effective way of collecting data.
