I'm fairly interested in railway stations and the associated micromapping that comes with them.

One particular thing that I'm interested in is getting platforms to render nicely on the main layer. It's not one of those crucial things, and obviously nobody's been interested enough to push it through to date, but once you start mapping at a higher level of detail, you'll get odd gaps in your map where platforms should be.

I noticed that some of the platforms around Brisbane started rendering sometime after the new API was released, and thought that maybe something had changed. Upon further observation I found that someone had simply added the tag "building=platform" so it would render as a building. This is wrong whichever way you look at it.

Then it occurred to me that because platforms are routable (area=yes,) and always allow pedestrian access (except I presume in some fringe cases,) so why not add the tag highway=footway and render it as a general purpose pedestrian area?

I implemented this on my local railway station, and it now renders rather sportingly as a light grey area on the Mapnik layer. I then went and applied it to the other station with the broken building tag, but it's yet to update.

I know what you're thinking, "Don't tag for the rendered!" and you're right, but I'd argue that this isn't necessarily a hack. I'd argue that it makes routing easier because it can direct pedestrian traffic along a platform (where appropriate) instead of having to know whether railway=platform can be traversed. I'd also put forward that if the Mapnik stylesheet ever were to be updated to reflect platforms they should render like this anyway because it's a neutral colour, keeps with the existing colour scheme, and is perfectly clear as to what it is.

So there's my justification, what's your opinion? Hack or neat trick? Should we work on the Mapnik stylesheet to implement this the “right” way, or would you consider this an appropriate measure?