Information Design in Public Transportation — Part I

Credits: Anne Morel

In the past centuries, cartographers — the true pioneers of information design — mapped out the world with all the intricate details they discovered. Of course, not everything could be unearthed at once, so there was often leftover spots on the paper for the great unknown. These white spaces were then covered by fantasy illustrations like sea monsters or imaginary islands in order to fill out the lacking pieces of information.

Today it’s almost the opposite. There’s almost too much information and it has become about reducing complexity. It is overwhelming to see the amount of data we absorb every day, most of it subconsciously seeping into our brains. This overload became apparent early on and almost instantly gave way to the discipline of Information Design, which emerged in the 1970s and reflects a science of presenting information in a way that fosters efficient and effective understanding of it.

Joel Katz — an information design expert and a pioneer in complex data visualization — distinguishes 3 types of information:

  • Information: what you absolutely must clearly communicate
  • Uninformation: is stuff that is not necessarily important and that is probably not true
  • Misinformation: pretends to be information, but it is not and it is likely to distort, confuse and mislead. Misinformation is not necessarily intentional but can be the result of a failure to interpret correctly the source data.

(Designing Information: Human Factors and Common Sense in Information Design)

Whatever the medium or the content, the purpose of information design is to deliver the right information to the user.

“Information needs to be in a form [the user] can understand and use meaningfully, and to tell the truth of what things mean and how they work.” — Joel Katz

The schematic representation of the metropolitan network

If we take a look at current maps, such as the metropolitan network of Paris, it is difficult to find any white space at all. There is so much information that you do not really know where to look:

Transit map of Paris (2019)

In fact, the Paris transit map is represented in the form of a “schematic diagram”, a term generally used to illustrate the link between symbols and lines in order to highlight the basic functions of a system. It is a simplified and geometric representation of the city, which helps us navigate through the different lines and branch points that make up the larger urban network.

This diagrammatic approach was first introduced by Harry Beck in 1933, who is famous for creating the current London Underground tube map.

Harry Beck (1933)

Beck’s assumption was that it is more important for Londoners to know how to get around the subway (ie. how to get from one station to another) than to know the geographical accuracy of each station. Therefore, he suggested highlighting the nodes and links of each line introducing a colour code, straight lines (horizontals, verticals and 45-degree angles) and a scale distortion in order to place all the stations at equal distances from one another.

Initially, a side-hustle project, Beck’s proposal quickly became so popular that the London Underground and most major cities around the world have used schematic diagrams to illustrate the network ever since:

Metro maps around the world

Paris Metro cartography

What about Paris you may ask?

Well, you will recognize the schematic diagram on the current map. But actually, it was rather difficult for Beck to convince the municipal authorities, who only accepted the diagrammatic representation in 1999 — long after Beck’s death. And it’s not like he didn’t try. Despite numerous iterations and two proposals to the city of Paris, Beck never managed to convince the French during his lifetime.

Beck’s first diagram of the Paris Metro (end of the 1930s)
Beck’s revised edition of the Paris Metro (1951)

What made it so hard for Beck to convince Paris?
First of all, the Parisian subway is denser than the London one. The lines intersect more between each other and this gives rise to more knots and exchanges, at the time there were about 50 in Paris compared to “only” 40 in London.

Secondly, Beck skewed the scale and opted for the massive expansion of the city centre involving the condensation of the suburbs. At that time, it was simply not necessary in Paris, because the whole system was already in the “centre” and they were only a very few stations in the suburbs.

It was only in the 1980s that RATP (the state-owned public transport operator of Paris) tried out pocket maps, which required the lines to gradually be straightened, equalizing the spacing of the stations and allowing a certain degree of abstraction.

Details of the current map (2019)

So, where do we stand today?
Right this second the Paris urban network has more than 300 metro stations, 89 bus lines and 10 tram lines. And within the next 5 years, bear in mind the upcoming Paris Olympics in 2024, the city plans to create four new metro lines including the extension of Line 14. This will allow faster connections between Orly airport to the city-centre and provide an additional way to access Saint-Denis, currently only served by the Line 13 — known as the busiest line of the network). It is the largest European urban project at the moment, which will require the development of 68 new stations!

Looking at Beck’s big ideas, I wonder if the schematic diagram would be the best cartographic solution to face such a growing metropolitan network?

Let’s go back and look at his principles…

Standardization of distances between each station:
One of the best advantages of opting for a diagram is reducing the proximity of the stations. But the spacing of stations in Paris is much denser than in any other city in the world. In almost all areas of the city, you can find a metro station every 400 metres. It is thus difficult to simplify the plan and distort the distances between two stations.

Straight lines and neat 45-degree angles:
In practice, this principle is difficult to achieve given the complexity and the density of the metropolitan network in itself (just look at the never-ending-Line 7 twisting around).

Map of Turgot (1739)

On the left is Turgot cartography made in isometric perspective which is a highly accurate and detailed map of Paris published in the 18th century. In fact, the RATP relied heavily on this map to carry out their public transport plans. And this could explain the French affection for pure cartography. It would be hard to imagine a metro map without any level of topography as the Parisians often use landmarks, like churches, parks, or unique buildings to find their way around.

The use of maps goes well beyond that of a simple metro plan. And it is an important detail since it is sometimes easier to walk from one station to another instead of using public transport. This is not necessarily the case for other cities.

Map of Paris Metro the RATP is based on the Turgot map (you can see here routes, buildings, parks and gardens, even the Eiffel Tower).

Establishing a colour code:
The increase in the number of lines requires a subtle and clear colour code so that commuters can easily differentiate the 14 (soon to be 18) lines of metros, 5 lines of RER and 10 tram lines. So the transit map has to have a set of primary (blue, yellow, and red for RER A) and secondary (green, purple orange) colours — but anyone who can count knows that this is not enough given the number of lines covering the network. And think of tourists or newcomers that can not read or understand the Roman alphabet and how they will have to try to navigate between fifty shades of green.

Which line is the “light green” one?

Information design and visual challenge

As a designer, I am wondering how could we simplify the transit map of Paris which — I think — has now become too complex.

I think the problem is that there is one single map that displays different kinds of information: subway lines, bus lines, RERs, tramways, links and changes, touristic highlights, access to airports,… — definitely too much information! And if you look at each individual, they only use a very specific part of this information and have no need to know about the whole infrastructure.

“Our job as information designers is to clarify, to simplify, and to make information accessible to the people who will need it and use it to make important decisions. Information needs to be in a form they can understand and use meaningfully, and to tell the truth of what things mean and how they work.” — Joel Katz

So why not have a single unique map personalized to everyone’s needs? Could it be a collaborative platform like Waze where people could share and update the status of the traffic instantaneously? Or why not map a network of users instead of traditional routes such as the SmartBus from CityMapper?

The challenge today is reversed. The amount of information is growing at a neck-breaking speed. This is partly due to the development of new technologies and the omnipresence of the internet that puts us into an ever-connected world. We are overwhelmed with information and the idea would be to lighten the amount of information load that saturates our brain every day.

Paradoxically, we’re also talking about “smart-cities” or how digital technologies help cities revolutionize the organization of the urban space — with the recurring debate on the progressive decline of the cars in the city.

These are all things Beck could not have anticipated in the last century and it is our job as designers, thinkers, tinkerers to tackle this challenge today!

Getting lost in the public transport rabbit hole