Japan: Megacity 3D Mapping.

Japan’s megacities are really 3D – they use the z-axis freely. The urban areas are high density, multiple levels, at high zoom – the cities provide a challenge to cartographers and openstreetmap. And then there are the underground streets!

Consider a normal 16 story tower block. In central London, we can expect these to be offices, no problem mapping these, representing the landuse. In Tokyo, or other large city in Japan, such a building will have multiple uses. Underground (Basement 2) shops and retail units as part of the underground street, leading to subways, still underground, Basement 1 may have restaurants and boutiques. Ground floor (1F) could be the building entrance, possibly a kiosk, bakery of cafe at street level. The remaining floors above ground: a university department, teaching area, library on two floors, three bars on another, restaurants on another. Offices on other floors, nightclub on another. Space is used. But it’s vertical. Even in smaller towns with shorter buildings, multiple uses on each floor is quite common. Signs outside showing whats on each floor are provided – but it’s still a bit weird going up four stories in a lift to a pub!

Megacity mapping in Japan. A challenge. Urban environment in small town

At the Tokyo micro mapping party at the IPA in Sugamo, we had a look at how openstreetmap can describe buildings. So for example “building:levels = 23” ; “building:-1 = post_office” “building:1-15 = office”. How these can be shown on a map is another matter.

A few of the new mappers in Tokyo commented how everything around was so dense, there was so much detail, that they wouldn’t want to map everything, as it would become to messy. Perhaps an additional level of zoom for high zoom levels would help here – although it does become too dense for GPS accuracy too – with small shops and restaurants packed up, down and left and right to each other.

hand drawn map of plots, houses etc kusakabe, shodoshima

The underground streets are quite confusing, a maze, but full of shops, pubs, eateries, people going from office block to subway or train station, from subway to pub, entering an office block at basement level and ascending up to seventh floor, all from under the streets. Not surprisingly, navigation is quite horrid. Maps do exist and are shown frequently (see below). Mobile phones work underground. Theres talk of rfid at exits, one company (Navitime) is selling (expensive) pedestrian navigation for mobile phones, and they include all the underground areas too – this company is heavily advertising on the trains and on TV. Personal pedestrian navigation on a phone…. I wonder how many years it will be until normal people in the UK get the same service?

navitime 3d building
Navitime 3D railway buildings & transfer directions, on phone. (from here)

A side note: on maps in public spaces. They always have the North arrow. Its quite important. Even outside, you will see it on the floor.

n arrow in park in shodoshima

However, the maps shown outside for navigation are not, in the main, orientated so that North is pointing up. Instead, the maps are orientated according to how you stand looking at the map. So if the map is on a sign at the edge of a road, as you face the map, the road going from left to right will also go from left to right on the map. The map below is a good example, but here, the map, written in English, for tourists, at a major tourism attraction, Ritsurin Park in Takamatsu, Shikoku, gives these instructions on how to read it to the reader. Look at this map while facing the mountain.

Megacity mapping. North arrows, cartography

OK, back to Megacity mapping. The mapping in Japan for OSM is gaining velocity. There was a genuine opinion from several people that their country would be completed soon, and quickly, and personally, I would not be surprised. Not only are there chizu otaku and enthusiasts getting involved, the government is showing positive signs, and characteristic of the project, there’s something for everyone to do.

Below is an animation of progress to date in OSM in Japan. Click on the animation for bigger better quality animation. Gives a good overview, I think.

openstreetmap progess in japan. Megacity mapping

In summary, I hope to see more attention applied to how we can capture, edit and make good maps of a proper three dimensional super detailed city. Otherwise, our maps will be just street-level maps, and will be unsuitable for normal people living and navigating these complex, dense places. Japan’s megacities and mappers could be a driving force.

EDIT: Kamakura Mapping Party (map) – First proper mapping party for Japan, probably later this month (May) – mapping Kamakura, a lovely town, by the sea, about an hour by train from Tokyo, and one chocked full of history, temples and atmosphere, and where I spent an afternoon seeing a couple of sights and adding a few things to the map. A great choice to have a mapping party!