exclude cul-de-sacs

docs/design/maps.md

@@ -261,6 +261,7 @@ I thought I had a list of these somewhere else?
 
 - min length for lanes, turns
 - connectivity
+- no loop lanes (same src and dst endpt)... but what about cul-de-sacs then?
 
 ## Border nodes
 

map_model/src/map.rs

@@ -108,9 +108,9 @@ impl Map {
 
         let mut counter = 0;
         timer.start_iter("expand roads to lanes", data.roads.len());
-        for (idx, r) in data.roads.iter().enumerate() {
+        for (_, r) in data.roads.iter().enumerate() {
             timer.next();
-            let road_id = RoadID(idx);
+            let road_id = RoadID(m.roads.len());
             let road_center_pts = PolyLine::new(
                 r.points
                     .iter()
@@ -120,6 +120,12 @@ impl Map {
             let i1 = pt_to_intersection[&HashablePt2D::from(road_center_pts.first_pt())];
             let i2 = pt_to_intersection[&HashablePt2D::from(road_center_pts.last_pt())];
 
+            if i1 == i2 {
+                // TODO Cul-de-sacs should be valid, but it really makes pathfinding screwy
+                error!("OSM way {} is a loop on {}, skipping", r.osm_way_id, i1);
+                continue;
+            }
+
             m.roads.push(Road {
                 id: road_id,
                 osm_tags: r.osm_tags.clone(),

map_model/src/pathfind.rs

@@ -378,8 +378,18 @@ fn validate(map: &Map, steps: &Vec<PathStep>) {
             error!("All steps in invalid path:");
             for s in steps {
                 match s {
-                    PathStep::Lane(l) => error!("  {:?} from {} to {}", s, map.get_l(*l).src_i, map.get_l(*l).dst_i),
-                    PathStep::ContraflowLane(l) => error!("  {:?} from {} to {}", s, map.get_l(*l).dst_i, map.get_l(*l).src_i),
+                    PathStep::Lane(l) => error!(
+                        "  {:?} from {} to {}",
+                        s,
+                        map.get_l(*l).src_i,
+                        map.get_l(*l).dst_i
+                    ),
+                    PathStep::ContraflowLane(l) => error!(
+                        "  {:?} from {} to {}",
+                        s,
+                        map.get_l(*l).dst_i,
+                        map.get_l(*l).src_i
+                    ),
                     PathStep::Turn(_) => error!("  {:?}", s),
                 }
             }