Write extra bits only if the road has nodes beside the start and end node. On the assumption that start and end points are always nodes, this should be equivalent to nodes.size()>2, but I've also seen .mp-files where the starting or end point were not routing nodes.
OK I'll change the test to n < points.size() - 1 then.
Does the change to RoadHelper actually do anything for your sample?
Yes it did, as there were only three nodes on the road but the first four points were not nodes and so the test against nodes.size() wasn't true. I think the reason that osm2mp used to give worse results was that it joins roads together if they are the same type and name. This gives more opertunity for the bugs to show as the ways in OSM are often quite short and end at junctions even when the road doesn't change. Cheers, ..Steve