NZRM Web Maps Update 2021-01-09

Good morning. As noted the NZRM Webmaps launched at 1 January and this website appears to be working successfully as a new step forward in making the maps more widely available and convenient to use. The site works best with recent browsers, so it is probably not going to be all that usable for people running old computers with Windows XP, for example. Other formats will continue to be produced and will be available to suit such requirements so one of the further considerations is bringing the previously completed image-based formats for volumes online as soon as the basic webmaps are completed, plus the other formats supported.

Today the first update to the basic maps adds the Main North Line from 0 to 193 km, which is about half way. The layers which have been produced are all the overlays, the items selected by check boxes in the lower section of the layer list, and the Maps base layer, which is selected by default in the upper section of the layer list (radio buttons). No aerial photography updates have been put into this update.

Next update in a week will include some of the following:

  • Waiau Branch, including historical aerial photography and yard diagrams of every station
  • The rest of the Main North Line to Picton, including 2016 post-earthquake aerial photography.
  • Basemap aerial photography (see below)
  • Rationalisation of aerial photo categories in the layer list

Linz have licensed the site to include their Basemaps aerial photography live layer which offers the most up to date aerial photography of every part of New Zealand. This includes high resolution coverage of a growing number of areas, even part of the Waiau Branch is included.

At the same time it is necessary to rationalise some of the aerial photography included in the webmaps as there are too many layers in the list. Whilst for design purposes it is desirable to have access to a wide range of aerials, for the webmaps it is preferred to have wider date ranges for ease of use. The current layer list in 1970-1990 provides two year date ranges, which will be altered into five year ranges, consistent with other decades. Whilst there are also numerous generations of Linz live aerial photography available, these will generally be removed in favour of Linz Basemaps. Certain parts of the Linz aerials will be included where beneficial, for example their available 2016 aerial layer covering part of the Main North Line after the 2016 Rotherham Earthquake.

It is important to note that the webmaps are not technically perfect and it has been noted that there are various rendering glitches visible. These cannot be easily resolved as they are a core limitation of the practical difficulty of rendering static raster XYZ tiles, the technology that is most practical for the NZ Rail Maps website. Being able to produce these webmaps at only the cost of annual web hosting is a huge leap forward for a free project such as this and there are going to be practical compromises to achieve this. The website itself does not have any facility for feedback, which is best done through the project’s Facebook page. Feedback should be limited to actual errors of the wrong information displayed on the maps. The project is aware of various issues with the maps and that they do need some corrections in places, and these will be addressed in due course.