Roberts has, he told The Local, always been interested in maps. And as a psychology professor at Essex University in the UK, he has had the chance to dig a little deeper into how people react and interpret them.
Last week, he put the finishing touches to a series of re-designed maps for Berlin's U-Bahn underground and S-Bahn commuter rail systems. They show the city's transport system in a completely different light and are each, Roberts thinks, simpler ways of displaying the complicated network.
Although the Berlin underground map is based on a standard technique comprising of horizontal, vertical and 45 degree diagonal lines, it seems simple until, “you are on the ground and trying to make sense of it, it really doesn't live up to expectations.”
So Roberts set about to transform the map – the centre of which is a convergence of multicoloured stripes that he found difficult to navigate, and messy. Lines U2 and U7 also disrupted the map as “they can't make their minds up,” he said.
“My aim is to show the network in the simplest possible way, with easy-to-follow straight lines across the page, and as few corners as possible, but not distorting geography so much as to upset people,” he said, adding that often, this means different angles are necessary from conventional ones.
Indeed the results are far from conventional, with concentric circles, jaunty angles and swooping lines rendering his maps eye-catching and eyebrow raising.
But he added that he found that Berliners seemed less sentimental towards their map than for example, Londoners. Longevity was a good predictor of affection he said, adding that Berlin's had changed too many times for a deep connection to be formed.
“It's not a very good design and lots of complex zigzags make the lines hard to follow,” Roberts explained. He said Berlin was a much more challenging network to map than London – his redesigned maps of which garnered lots of attention online – because the system had less shape.
He did warn though that breaking the rules of map-making required beginning with a clear aim. “It's very easy to come up with something that is shocking for the wrong reasons and incoherent,” said Roberts, adding that “People judge innovation harshly in the map world, so you have to anticipate their objections.”
When it came to using the maps, Roberts admitted that he had not personally tested them in Berlin but was trying to get an idea of the factors that determined individual preferences.
“Some people love maps based on curves, other people declare them to be unusable and claim that maps based on straight lines will always be easier to use,” he said.
Interestingly though, his research has shown little correlation between preference and usability. “Ask people to pick the map that they prefer, and it won't necessarily be the map that they found easiest to use,” he said.
While the professor thinks his maps are more accessible that the pre-existing one, Roberts said he had no plans to offer it up to the city's transport operator BVG. “Large bureaucratic organisations dislike the thought of outsiders coming along and trying to improve on their work.”
Outside of Berlin, Roberts felt Cologne had a more usable map, with a clever use of colours making light work of a complicated tram system. Frankfurt was too colourful and on his last visit, Rostock's was “a bit mad.”