Saturday, 8 December 2012

NZ Rail Maps Development Strategy

When I first put together the NZ Rail Maps website (the old one) I had a development strategy for the project. For this second edition there will also be a strategy.
Maps will be developed at three levels. Each level will be reflected in the major version number of the map (the part before the decimal point).
  • Level 0 is what is currently being developed. Essentially this is just drawing in the basics of routes and stations from the source maps. The Canterbury-Westland project will be more unique in that a lot of additional work has been done; however, as of today, maps will be developed at the Level 0 criteria.
  • Level 1 is a more indepth treatment in which additional detail is being filled in. Likely this will include additional stations and bridges which are not found in the original maps.
  • Level 2 aims for completion and is likely to include bush tramways and other lines that are not part of the national railway network.
In addition a comprehensive key is still being developed. The two sets of images below represent the current edition (0.7) of the key.


The symbols are used at fixed locations on maps to illustrate features that are or were found at these locations. The set shown above is reasonably comprehensive and has not changed markedly in the last few editions of the key. However I opened the XML file today and renamed all the symbols so the names are meaningful and follow a standard format. Below is the symbols as they were at 17th November so you can see quite a few changes. One symbol has been removed and that is “points”. I experimented with showing where a set of points was located on a track diagram but have decided to remove the unnecessary extra detail. “Rail Placename Holder” has been given the more meaningful name of “Uncertain Station”. This is always a closed station by definition, just as “Current Service” is always an open station by definition, and thus these two use complementary symbols but unlike most of the others are not a current/former pair.



Now let’s have a look at paths, which is the other main type of style used in the maps.



Once again, an earlier style set is below.




Paths is the area where the key has most changed in recent editions. As you can see, path names have been standardised with “open” replaced by “current” and “closed” replaced by “former”. Bridges and tunnels now have three styles corresponding to the three global layers used. In both cases, Current is used exclusively for rail bridges or tunnels, while Former can refer to both rail and non-rail bridges or tunnels. Other is used to refer to current non-rail bridges or tunnels and it includes road types, as well as bridges or tunnels on former rail routes where the structure is possibly or definitely not the original rail structure. Note there used to be a “reconstructed bridge” style which has been rolled into “Other Bridge” to simplify things.

Originally the path style “Uncertain Formation” was not planned to be in the maps but it covers two scenarios that I have used before. The first of these is using the standardised caption “Inexact Route” because I have discovered that I do not have a source map for part of the Roxburgh Branch route and this may also be the case for a small number of other lines. The same path will be used for hypothetical formations, with the standardised caption “Hypothetical Formation”. Both will appear on the main maps but will be clearly marked using either of those captions as appropriate.

Some of the more recent other changes in paths include: aerial ropeways, closed sidings, closed tramways, and present and former rail corridors. In all cases I have attempted to create paths that are clearly distinguishable from each other. There are certain stylistic similarities related to the status of each type of path and I have attempted to produce a consistency in these, but this is not always possible owing to obvious challenges. The biggest improvement over Google Earth is in being able to use the different path styles. In GE I could use colours instead of styles. However, in order to be printable, these maps have to be clearly rendered in grayscale in which colours are of no account. The path shown for a river has been changed from the above so that it is more easily distinguishable from a road. Everything has to be able to be printed on a monochrome printer because colour printing is still far too expensive. The contour line path  has also been changed recently to be less obtrusive and also easier to distinguish from the river and former road paths.

Whenever a key is updated, it is going to be some time before the new key is included in all previously published maps. At Level 0, the keys of existing published maps will not be revised unless the map graphics are being updated. In addition the maps themselves will not show the new symbols or paths where there has been a change, unless the map itself has been updated, at Level 0. This reflects that at level 0 the map designs are still being refined and may change quite often. Once I get all the level 0 maps published I expect to have finalised all the styles that are needed and be able to update all the maps with their Level 1 revisions.