Hi all, and Andy in particular, as the past weeks went by while entering cycle routes for Belgium into OSM, I've come across several issues. It's a big mash-up of needed tags and improvements, so here goes...
* Tagging of alternate routes: Some routes have shortcuts, or in general alternate ways (e.g. for when a route is blocked due to the weekly market day, it's possible to follow another signed route, or sometimes there's an alternative for cyclists who don't like sandy roads). These routes are generally marked as a dashed line on most maps I've seen, to make sure it doesn't look like the main route. I guess a tag as "route_special=alternate" added to the route relation works for that to make that happen. I don't think a "route_special=shortcut" is needed, after all, it's just an alternate. * Tagging of connection routes: Connection routes are routes which bring you either from one route to another one, or from a route to an interesting location like a city center (or the other way around). These routes also need to look differently on the map. In the maps I've seen they usually do it by marking them with a different colour, but I understand that may be a problem with different networks on one map, so maybe a dotted route perhaps? Anyway, I propose a "route_special=connection" tag for these. * Rendering when different networks (local, regional, national) are on the same way: It's somewhat solved on the highest zoom in the cycle map by having transparent ways, but in lower zooms it gets messy since it's apparently a random one that "wins" for each section. I've seen two different approaches on the maps I've seen so far: - alternate colours: the section are coloured e.g. red-blue-red-blue-red-blue (but becomes a problem for more than one network) - different networks = different line width: this is my personal favourite solution for this: make national routes wider than regional ones, which are again wider than local ones. So you can easily show three routes on one way if needed. You only need to make sure to draw to thinnest routes last of course :-) This solution also works nicely with dashed lines like mentioned above. * Preferred colour for the route: Now let me first say that this isn't for giving all national routes the colour "green" for example instead of red in country X. I want to use this to distinguish routes on the same level which can run into each other. I don't know if something similar exists in the UK, but over here it's needed for our local routes: these aren't really a network, but they're themed routes which make loops, and those loops overlap each other, sometimes two or more of them follow the same road for a short distance. So, when making them all the same colour on a map it becomes a route cloud in which you can't see the exact loops anymore, and you have no idea anymore how the routes go. Again, this is usually solved by different colour on maps, so that's why I propose here an "abstract" "preferred_colour=X" tag, where X could be a number between 0 and 5. The renderer can then choose its palette and assign colours to them which suit the map and which don't clash with the colours of other networks (like all shades of blue for local routes, shades of red for national routes etc). The person entering the route in OSM then just need to make sure that no two routes of the same colour overlap. The problem of having two different coloured routes of the same network level on one road is then solved by alternating the two colours on the shared road. * Route starting points: As the title says: this is for points where a route starts (the local loop routes for example all have a starting point), usually near a parking, sometimes at a symbolic place after which the route was named. For rendering this could be a big dot, together with the name of the route and a reference if it has one (that also happily solves the current issue of not seeing the names for those routes which have no reference numbers). (possible in the same colour as defined by "preferred_colour" when two routes start from the same place). Okay, I guess that's a nice set of issues to start of with :-) Any ideas or opinions? Greetings Ben _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk