A bank of gravity lanes between the same two Kreisel (same slope) was
drawn as one box per lane, making large storage banks unreadable.
render_dot now collapses such lanes into a single Gefaellestrecke-styled
block with a double border, labelled with the id range and combined
Separator/Scanner ranges. Purely visual - the graph, --doc report and
--connect output still list every lane individually.
m.stangl
s.ayadi