With a reassuring squeeze of my arm, Richard Holmes guides me along a busy city centre street. I’m wearing a special pair of glasses that have deprived me of my normally good eyesight. Instead of the crisp lines and textures of the city, my field of view is filled with little more than faint smudges of light. The growl of passing trucks, disembodied voices and the occasional blare of a car horn is disorientating, and the urge to find a wall and shuffle along overwhelms me.
Then I feel it – a strangely comforting change in texture under my feet. I have just walked over a piece of ‘bubble paving’, a section of pavement covered in round bumps which is designed to help people with sight problems identify pedestrian crossings. I have walked over these L-shaped patches of dimpled pavement almost every day on my way to work without a second thought. Now, they suddenly take on meaning.
Holmes is a regional campaigns officer in London for the Royal National Institute of Blind People (RNIB). He suffers from a rare inherited condition that leaves him only able to make out vague colour contrasts around him. Yet he is able to safely pick his way through the hectic city streets, thanks to dozens of hidden messages embedded in our roads and pavements that few of us even notice are there. (Some were highlighted in this recent video by comedian Tom Scott, which was filmed with the RNIB). Holmes has been pushing city planners to build more of these aids for the partially sighted into the streets.
But many of these textured pavements are also passing messages to sighted people as well – without them necessarily realising it. This subtle form of communication is not just confined to the pavement, either: increasingly, motorists and cyclists are also unknowingly being told what to do.
Among the most striking examples to appear in towns and cities around Britain are the ladder and tramline patterns that mark the start of shared cycleways and footpaths. A horizontal pattern of raised lines going across the pavement tells blind pedestrians they are on the footpath side; raised lines running along the direction of travel indicate the side designated for cycles. A wide, raised line divides the two. “These tell me straight away which side of the path I should be walking on,” says Holmes.
But something else happens here, too. Because the raised bumps are unpleasant to ride across, cyclists instinctively are drawn toward the tramline pattern which runs in the same direction as they are traveling. “It ensures the cyclists stay on their side of the path,” Holmes says with a grin.
There is a bewildering array of textured paving on the roads of British towns and cities to convey similar messages. Dimpled paving set out in a grid-like pattern, for example, indicates a point where the kerb drops at a road crossing. If the dimpled paving forms an L-shape across the entire width of the pavement, it means that this is a pedestrian crossing with lights.
For those who know where to look, another secret message lies hidden around pelican crossings – the pedestrian crossings in which someone pushes a button, then waits for the signal to walk. Tucked on the underside of the box with the push-button is a small, innocuous cylinder. When the lights change to show the green man, this cylinder spins to indicate it is safe to cross. Wearing my blindness simulation glasses, it feels like the top of a felt-tip pen spinning in my hand.
“It is a hidden, unknown benefit,” says Holmes. “Not many people know about these tactile indicators at crossings.”
Elsewhere, it is possible to find raised, rounded ribs running across pavement, creating a corduroy pattern. They look like they might be there to provide additional grip; in fact, they are sending a warning to anyone who stands on them about what is ahead. These indicate you are standing in front of a hazard, like a set of stairs or a level crossing.
Train passengers already will be familiar with the coloured slabs studded with flat-topped domes that indicate the edge of a platform. While these can tell someone with sight problems they are at the platform edge, passengers also will instinctively wait behind them as they are uncomfortable to stand on.
Other forms of this pavement messaging system are less common. Lozenge-shaped blisters indicate the edge of an on-street light rapid transport platform. Then there are information surfaces – a change in texture that is sometimes placed in front of key amenities like telephone kiosks, ATMs, ticket offices or post boxes.
In pedestrianised areas, some local authorities also have installed textured pathways with flat-topped bars running in the direction of travel. The idea is to guide people through busy areas and around objects by drawing them along these raised lines. For visually impaired pedestrians, they are invaluable. At London’s Old Street tube station, for example, a bright green line stretches out of the station from the ticket barriers, up the stairs, along the pavement – and right to the door of the Moorfield’s Eye Hospital.
On the roads, however, hidden messages are being used not only to guide people – but to manipulate them.
In Norfolk, the county council has planted nearly 200 trees alongside the roads approaching four local villages. In recent years, the quiet, rural settlements of Martham, Mundesley, Overstrand and Horstead had found their peace being destroyed by drivers speeding along their main streets.
The trees were part of an experiment in 2010 to stop that. By planting oak, maple, birch and hornbeam on either side of the road so that the trees got gradually closer together and also nearer to the edge of the road, it created the illusion that motorists were going faster than they really were as they approached the villages – even if they kept their speed constant. In initial findings, drivers went an average of 2mph slower; accidents were cut by 20%. As the trees grow, the scheme’s proponents hope the effect will increase.
Planting trees on either side of the road so they got gradually closer together created the illusion that motorists were going faster
Other villages have taken alternative approaches to slowing traffic. Installing gate-like structures on either side of the road where the speed limit drops from 60mph to 30mph, for example, gives drivers the message they are entering a different type of area and so should change their behaviour. Some reports say these can reduce the speed of cars entering a village by up to 10mph.
The Transport Research Laboratory in Crowthorne, England, has conducted research into how other sorts of so-called ‘nudge’ measures can alter driver behaviour. They found that uncertainty about the layout of the road ahead is a powerful way of getting drivers to slow down.
In their tests, changing the texture and colour of the edges of the road can create the illusion that the road is narrowing, causing people to reduce their speed to compensate. ‘Dragon’s teeth’ – triangles painted along the edge of each road – create an impression of a narrower road for example, and make drivers more cautious.
“The idea is to increase the perception of risk so that drivers choose to decrease their speed but without actually increasing the risk,” explains Nick Reed, a transport psychologist and academy director at the Transport Research Laboratory.
On motorways in Britain, the white lines between lanes are used to tweak the way drivers behave. Approaching a junction, the lines become longer and the spaces between them smaller. After the junction, they get shorter and have larger gaps between them.
“This is indicating it is less appropriate to change lanes before a junction as you have a lot of traffic moving about as cars join the carriageway,” says Reed. “It is an intuitive signal that indicates a change in the road conditions.
“There are a lot of things like this that people probably recognise, often without even being aware of them.”
Motorways also feature cats-eyes which communicate with drivers
Motorways also feature cats-eyes – also known as ‘studs’ – which communicate with drivers. Red studs mark the hard shoulder, white mark the lanes and amber studs show where the edge of the road starts beside the central reservation. Green studs reveal the location of the main carriageway at slip roads and lay-bys. Some of these road studs even change colour in the weather, turning blue in icy conditions.
On a busy roundabout just outside Edinburgh, the studs have been linked up with the traffic lights: when the signals turn green, the studs in front of those drivers light up, guiding motorists around the roundabout in the correct lane.
The texture of the road itself can also steer drivers’ behaviour. Rumble strips – raised stripes on the surface of the road – are commonly used to encourage people to slow down, but in some parts of the world these convey more complex information.
By changing the depth and spacing of the strips, they can produce different vibrations that can alter a driver’s perception of speed. In Japan, these strips have been tuned to the point that they produce a musical melody as the car passes over them. Cleverly, the melody only sounds right if the driver motors over them at a safe 40mph.
In London, transport officials have taken the trickery to new levels. They have been painting boxes onto the road that use a clever combination of white and dark paint to create the illusion of a speed hump. Other attempts at this appear around the country, such as white lines at the side of the road that get thicker at one point to give the impression of a speed bump, or triangles that are painted facing each other on a flat piece of road – just as they are on actual humps.
In India, they have taken things even further by painting deliberate optical illusions to give the impression that obstacles are in the road ahead.
We need to start looking at making roads that not just humans can read, but also robots – Nick Reed
Regardless of how successful these attempts are to get the roads and pavements to ‘speak’ to the people who use them, though, there are some new challenges on the horizon.
“We are moving towards automated vehicles,” says Reed. “We need to start looking at making roads that not just humans can read, but also robots can read. We have all this information we have put into the roadways to communicate with human drivers, but how do you communicate that with machines, as they start to take control of cars?”
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