[mkgmap-dev] Different representations according to resolution

Is it possible to use different types at different resolutions? Example - I'd like a motorway to be a thin line when I'm zoomed out to 50km scale, but quite a thick line at the 120m scale. Also, it would be nice to have roundabouts rendered in the correct colour (motorway, trunk, primary, ...) but still appear as 0xc in the routing layer.