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The art of sensory design

Tours’ tramway is an exemplar of modern sensory design techniques. Image credit: RCP Design Global

Our perceptions of the world are built upon the interactions of our senses. They help us comprehend our surroundings and are powerful drivers of both positive and negative emotional responses, affecting our feelings about a product or service.

It is also a fallacy to believe that in particular situations one sense assumes dominance. When listening to someone speak you might think that your hearing is ‘in charge’ – but as our brains process all the available sensory information together, it is important that all five senses work in harmony to communicate a single message or brand value.

Any estate agent will tell you that baking a fresh loaf of bread or having a pot of coffee on the stove will generate a more favourable association of ‘home’ than just cleanliness alone. Likewise, as masters of the art of ‘sensory engineering’, automobile manufacturers spend fortunes on tuning the sound of a door opening or closing to create that reassuring feel of quality, calibrating the note of an exhaust to demonstrate power or performance, or making subtle changes to the texture or feeling of a vehicle’s switchgear.

This science of sensory design is relatively new to public transport, despite examples of minimal investment paying dividends in terms of customer satisfaction and ridership. It just requires imagination and a better understanding of the five senses.

As Régine Charvet Pello from French transport design specialist RCP Design Global explains: “Giving a form and a colour to a tram is not design, that’s styling. We analyse how passengers behave: do they stand? Do they sit? Do they read? What kinds of items do they take with them and what do they touch when onboard the tram? It is all about creating an atmosphere of comfort and safety.”

RCP has spent decades scrutinising the passenger experience, seeking to create more relaxing and intuitive journeys. Temperature, texture, colour, sound, luminosity and materials are all important instruments in the company’s toolbox. Taking examples from the tram project in Tours, France, where RCP is based, Ms Charvet Pello explained: “Normally when you have tenders in France you ask the manufacturer to come up with a tram design. This time we put all the actors on the project around a table – technicians, designers, politicians, urban planners, psychologists and architects. They all worked on the concept of ‘what is a tram’, and what kind of tram does this city in particular need?”

The system that opened in August 2013 uses a range of techniques to better connect its vehicles and infrastructure to a passenger’s emotions to create that feeling of comfort and safety – and it’s working well. Thousands more in this city of 300 000 are leaving their cars at home, with 36.1m passenger journeys recorded in 2017, and 50% more people are using the tramway than the bus line it replaced.

Ms Charvet Pello continues: “We know that sensory design facilitates the use of the tram. It also promotes public transport as a whole by creating connections with bus and rail services, changing the city’s fundamental infrastructure and at the same time supporting its identity.”

As cities expand, more people are using trams, metros and buses as the most efficient forms of urban travel – but this success brings its own challenges. Public transport anxiety affects significant numbers of travellers and as fear is well-known for over-riding all other emotions, busy or complex networks can be a cause of stress and bewilderment.

Crowds, confined spaces and interaction with strangers all play their part in feeding this anxiety, yet without major investment in new infrastructure and more vehicles, sensory design can address these barriers cost-effectively to make a massive difference.

Sight. More than half the brain is devoted to processing visual stimulus, and 80% of learning is based upon visual input. As Ms Charvet Pello explained: “Sensory design gives intuitive ways of using public transport. We worked with an artist who created the white and black stripes that we put on both the tram and the platform to direct people to enter and exit the tram at all doors.

“Because we took the tram out of Tours in 1948, in order to explain to people not to all line up at the front, this simple, artistic visual code explains that they could enter and leave at all doors. Just follow the stripes and get onto the tram. This has been very successful.

“We also know from our testing that if a tram is perceived as clean then it adds to the comfort. The dark floor materials do not show marks; it doesn’t mean they are gone, just harder to find. On the seats we use velvet, not because velvet is cleaner than other fabrics but it absorbs the marks better so it looks cleaner.”

“We use light in relation to temperature comfort as well. The tram shelters use transparent and slightly opaque sides to protect people from the wind, the rain, but also the sunshine. Special glass prevents solar radiation from warming up the stops. A similar principle is applied to the trams’ windows.

“We have also carried out extensive research on how lighting changes the perception of temperature when indoors. We tested a pure white ‘cold source’ LED and a ‘warmer’ light and found that the testers perceived the temperature under the white light as 2.5-3°C lower than the actual temperature. All this affects comfort.”

Sound. Getting your message across is as much about the choice of a voice as it is about volume and clarity – get it wrong and important announcements are ignored or go unheard. In Tours, RCP chose simple sound codes, as Ms Charvet Pello explains: “We opted for a female voice as studies have shown that female voices are more comforting and reassuring. However, a male voice is proven to give more authority so in emergency situations the announcements change when giving you instructions on where to go.”

In Rotterdam, as part of a series of multi-sensory experiments in 2015 at the city’s new Centraal station, operator RET undertook a trial to alleviate the frustration associated with waiting times using a programme of specially-developed music, scents, lighting and decorations.

Scientific research showed RET that station waiting time is not only over-estimated by a factor of three, but it is also perceived to be much more negative than in-vehicle time. So while the glass and stainless steel station that opened the year before is smart and easy on maintenance, the new environment was also identified by passengers as cold, sterile and overly clinical – adversely affecting the comprehension of waiting times.

A new music programme was created, using different styles for different times of day, beginning with natural sounds early in the morning to connect with the mood of passengers who may have just got out of bed, and adopting a relaxed tempo during rush hour to combat background noise and promote feelings of calm. A more lively style was used following rush hour as more travellers use the system for recreation.

The mostly instrumental playlist was selected randomly so that commuters were not confronted with the same music each day; this was also easily adapted for special events such as the city’s hosting of the North Sea Jazz Festival or to specific station environments. For instance, the playlist at Blijdorp (the Zoo) contained more animal sounds to add to the atmosphere of this station.

Following the trial, feedback on station environments was recorded as more positive and the overall general customer satisfaction score went up a few points.

Smell. Scent is a very powerful instrument in influencing a person’s mood. It’s the first sense we use when we’re born and this strong emotive link has been exploited by hotels for decades, using signature scents to encourage brand loyalty and feelings of comfort.

In its 2015 pilot, RET infused the air of its metro stations with a subtle combination of citrus and green nuts. Even for barely noticeable aromas, the brain is capable of detecting and reacting to scents and this was used to promote emotional responses of security and cleanliness. RET’s research showed that enhancing these two emotions encouraged passengers’ feelings of control of their situation, removing anxiety.

Such ‘scent marketing’ can even be used to drive business more directly. In 2012, Dunkin’ Donuts found some striking results following its ‘Flavor Radio’ trials on buses in Seoul, South Korea. Special dispensers distributed the aroma of the brand’s fresh coffee whenever its advertising jingle played on the public address system. The company claimed the three-month trial resulted in a 16% increase in visitors to stores located near stops served by buses equipped with the technology, and a 29% increase in coffee sales.

Touch. While the common plastic or moquette seat coverings may be the most practical – durable, easy to clean and vandal resistant – their design is also important. Given that trams and metro vehicles are designed to last for 20-30 years, what could be in vogue now may well look out-dated in 2045. All these factors need to be considered as part of overall sensory design, Ms Charvet Pello argues.

“For the benches at stops we originally thought of using steel, but steel is very warm in summertime and cold in winter, so we decided to use wood. But wood is quite expensive and requires more maintenance, so we tested three types of material – real wood, decorative vinyl and laminate (wood and resin). Our testers felt the laminate looked and felt more like wood than wood itself – and it was less expensive.

“Then we looked at handrails on the trams. Using previous work with the French national railway we observed that passengers didn’t like to hold onto handrails because they perceived them as unclean. Smooth plastic provides a warm and slightly greasy touch, so we ran trials with both testers and passengers and found that if we polished it slightly more roughly it provided a dry touch. It costs no more money to polish it in a different way, but it provides a better feeling of comfort.”

Spatial awareness. There are certain physical constraints that restrict what can be done within the typical modular design of tram or metro car. But as cramped or tight environments are the stated number one cause of public transport anxiety, in Tours a number of simple solutions were found: “Nobody likes the closed and narrow spaces sometimes found in public transport,” Ms Charvet Pello says, “so to take away that ‘tunnel effect’ we painted one wall red and treated the other to a different colour and a different material. We can’t push the walls back, but we can use visual tricks to provide what appears to be a wider space.”

“We also know that what people find most tedious in everyday travelling is that they are always seated in the same way and treated the same way. So we studied how people behave when waiting in different situations and came up with a new layout by using standard materials but in a different way.

“This provides people with something that is more comfortable and more attractive. I can be isolated if I want, or I can sit with someone else and talk – I have that choice as a customer.”


As an example of the level of attention to detail which designers use in connecting with passengers, over the last three years RCP has worked with a doctorate researcher to observe, document and analyse how people engage and interact with urban transport systems.

Looking at behaviours across 12 cities in seven different countries, and paying particular attentiveness to passengers’ expectations concerning space, perception and practices in urban transport, almost all behaviours observed displayed common traits.

A very small share showed distinct cultural and environmental characteristics and this is where the secrets lie in creating those emotional links, Ms Charvet Pello believes. It is the designers’ job to cater for these when encouraging feelings of comfort and safety.

Sensory design offers a range of approaches to connect with passengers, reinforce the key values of your city or transport system and encourage brand loyalty. Simple but well thought-out measures such as those outlined here can cost-effectively meet passengers’ needs, while also taking into account technical constraints within a given budget and make public transport more attractive and more user-friendly.

It doesn’t need to cost the earth, but the benefits shown in Tours and Rotterdam make sensory design worth the effort.


Article originally appeared in TAUT 972 (Dec 2018).