Railmaps for different uses [2]

Here are 2 pictures to illustrate what was discussed last time.

A small scale QGIS map	The equivalent page of the NZ Railway and Tramway Atlas 4th Edition.

At a quick comparison there appear to be some geographical differences (apart from detail) between the QGIS sourced map and the Quail sourced map. Which leads me to believe that a map sourced from QGIS is going to be inherently more accurate. One of the more obvious examples is the placement of Greta station. On the Quail page at right, Greta is listed at 5 km north of Scargill, yet the distance appears to be similar from Scargill as the distance to Spye, which is 10 km south. There are also some less major differences obvious in the maps of the Waiau Branch.

Railmaps for different uses

This is a good time to be thinking about the different uses (or markets) which exist for maps in a printed format, which is the format that the majority of users are likely to relate to. Electronic format can be handled with GPS which is a different strand of interest and is not presently a high priority. QGIS includes GPS features and I will look at these at some stage, as well as the possibility of exporting some data into Google Earth KML files. However the most important priority as of now is the printed formats and I won’t be considering anything in another format until there is a Level 0 map produced for every NZR line in New Zealand.

Smaller scale maps for people such as long distance passenger or excursion travellers who are less interested in the detail, is an important consideration. A way of achieving this is to produce the main map (such as MNL) in an overall smaller scale. The 75 page map is suitable for those who want to find specific locations en route, however for open lines there is considerably less interest than for closed branches where the extra level of detail from the large scale is useful because it is much more difficult to find aspects of the line. A smaller scale map would be likely to omit some of the extra data such as street names and contours that are present in the large detail maps as they are drawn. Because it is much more difficult to control the display of data from other maps (for example, all of the stations in each region are presently in the same map layer), at this point I will have to move to dispensing with global layers except for LINZ layer data that is impractical to localise, and placing all the features and paths that are not directly sourced from LINZ into regional layer files. Probably even into line specific files. Therefore the template files will be updated so that there are sectional templates for these.

So that is where the work will also go in the next week in the two currently in existence regional projects (Canterbury-Westland and Nelson-Marlborough) in reorganising their layers. I am also considering another proposal which is to organise all of the projects on a sectional basis. That is that there will be a specific project for each of the major lines (the folders that are in the root folder of the project as they can be seen on SkyDrive). The regional organisation to date for the projects has been naturally organised this way as it is based around the organisation of the LINZ data layers. However, provided that all of the LINZ data layers are organised in a logical and easy to find way, there is no reason that this constraint should apply to the organisation of the projects and the custom layers. There is no issue with data duplication as the LINZ data layers will be placed into a common repository folder structure that can be accessed by all of the projects. Within each project there will be separate layer groups for the branches and heritage lines which are associated with each of the major line routes. This will enable full control of the displayed data for different lines depending on what sort of printed format is desired.

These questions are the reasons why the NZ Rail Maps project has proceeded slowly to date and why I have ignored requests to produce maps for other regions. There is quite a lot of work in these reorganisations. At a practical level, all of the datasources in each project contain a hard coded file path, and these have to be updated manually when the datasources get moved around on the computer. For example, today I reorganised the Skydrive folder structure to place a folder for each line at the root of the project, which contains the output map files, and a Sources folder in the route, which contains the redistributable layers. This level of reorganisation means 252 path references in the project .qgs file have to be updated with the changed locations (because the project file itself is saved in a slightly different location as well). As the project file is stored in XML format it is simply a matter of opening that in Notepad++ and doing a global find and replace (after making a backup copy of the project file, of course!). Since I also have to change the paths for the fixed layers I may as well create a proper repository structure for these that is easy to follow. This means yet more work. However once these decisions are made and implemented they will be followed for the remaining regions and the extra work isn’t needed. You can see that by piloting these changes over only the two current regions I have saved myself a lot of work later on in changes to other regions if I had pushed ahead and created all of these already.

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.