gracefully degrade if we cant make TurnGroups for a traffic signal. this

gets SF, Tokyo, and London to import!!!

convert_osm/src/transit.rs

@@ -221,8 +221,12 @@ pub fn snap_bus_stops(
             for idx in (0..idx_in_route).rev() {
                 let (i, pt) = route.all_pts[idx];
                 if !raw.intersections.contains_key(&i) {
-                    found = Some(pt_to_road[&pt.to_hashable()]);
-                    break;
+                    if let Some(r) = pt_to_road.get(&pt.to_hashable()) {
+                        found = Some(*r);
+                        break;
+                    } else {
+                        return Err(format!("Some point on the route isn't even on a road?!"));
+                    }
                 }
             }
             if let Some(r) = found {

geom/src/line.rs

@@ -9,7 +9,7 @@ pub struct Line(Pt2D, Pt2D);
 
 impl Line {
     pub fn new(pt1: Pt2D, pt2: Pt2D) -> Option<Line> {
-        if pt1.dist_to(pt2) < EPSILON_DIST {
+        if pt1.dist_to(pt2) <= EPSILON_DIST {
             return None;
         }
         Some(Line(pt1, pt2))

geom/src/ring.rs

@@ -120,7 +120,7 @@ impl Ring {
         for pt in pts.iter().cloned() {
             current.push(pt);
             if intersections.contains(&pt.to_hashable()) && current.len() > 1 {
-                if current[0] == pt {
+                if current[0] == pt && current.len() >= 3 {
                     rings.push(Ring::must_new(current.drain(..).collect()));
                 } else {
                     polylines.push(PolyLine::new(current.drain(..).collect())?);

map_model/src/make/mod.rs

@@ -13,7 +13,7 @@ use crate::raw::{OriginalIntersection, OriginalRoad, RawMap};
 use crate::{
     connectivity, osm, Area, AreaID, ControlStopSign, ControlTrafficSignal, Intersection,
     IntersectionID, IntersectionType, Lane, LaneID, Map, MapEdits, PathConstraints, Position, Road,
-    RoadID, Zone,
+    RoadID, TurnGroup, Zone,
 };
 use abstutil::{Parallelism, Timer};
 use enumset::EnumSet;
@@ -141,7 +141,9 @@ impl Map {
             }
             // TODO Maybe easier to use the road's "yellow center line" and shift left/right from
             // there.
-            let road_left_pts = map.must_left_shift(road.center_pts.clone(), r.half_width);
+            let road_left_pts = map
+                .left_shift(road.center_pts.clone(), r.half_width)
+                .unwrap_or_else(|_| road.center_pts.clone());
 
             let mut fwd_width_so_far = Distance::ZERO;
             let mut back_width_so_far = Distance::ZERO;
@@ -306,14 +308,28 @@ impl Map {
                 IntersectionType::StopSign => {
                     stop_signs.insert(i.id, ControlStopSign::new(&map, i.id));
                 }
-                IntersectionType::TrafficSignal => {
-                    traffic_signals.insert(i.id, ControlTrafficSignal::new(&map, i.id, timer));
-                }
+                IntersectionType::TrafficSignal => match TurnGroup::for_i(i.id, &map) {
+                    Ok(_) => {
+                        traffic_signals.insert(i.id, ControlTrafficSignal::new(&map, i.id, timer));
+                    }
+                    Err(err) => {
+                        timer.error(format!(
+                            "Traffic signal at {} downgraded to stop sign because of weird \
+                             problem: {}",
+                            i.orig_id, err
+                        ));
+                        stop_signs.insert(i.id, ControlStopSign::new(&map, i.id));
+                    }
+                },
                 IntersectionType::Border | IntersectionType::Construction => {}
             };
         }
         map.stop_signs = stop_signs;
         map.traffic_signals = traffic_signals;
+        // Fix up the type for any problematic traffic signals
+        for i in map.stop_signs.keys() {
+            map.intersections[i.0].intersection_type = IntersectionType::StopSign;
+        }
 
         traffic_signals::synchronize(&mut map);
 

map_model/src/make/traffic_signals.rs

@@ -70,7 +70,7 @@ fn new(id: IntersectionID, map: &Map) -> ControlTrafficSignal {
         id,
         phases: Vec::new(),
         offset: Duration::ZERO,
-        turn_groups: TurnGroup::for_i(id, map),
+        turn_groups: TurnGroup::for_i(id, map).unwrap(),
     }
 }
 
@@ -428,6 +428,7 @@ fn make_phases(
 
 pub fn brute_force(map: &Map, i: IntersectionID) {
     let turn_groups: Vec<TurnGroup> = TurnGroup::for_i(i, map)
+        .unwrap()
         .into_iter()
         .filter_map(|(id, tg)| if id.crosswalk { None } else { Some(tg) })
         .collect();

map_model/src/objects/traffic_signals.rs

@@ -306,7 +306,7 @@ impl ControlTrafficSignal {
             id,
             phases,
             offset: Duration::seconds(raw.offset_seconds as f64),
-            turn_groups: TurnGroup::for_i(id, map),
+            turn_groups: TurnGroup::for_i(id, map).unwrap(),
         }
         .validate()
     }

map_model/src/objects/turn.rs

@@ -197,7 +197,10 @@ pub struct TurnGroup {
 }
 
 impl TurnGroup {
-    pub(crate) fn for_i(i: IntersectionID, map: &Map) -> BTreeMap<TurnGroupID, TurnGroup> {
+    pub(crate) fn for_i(
+        i: IntersectionID,
+        map: &Map,
+    ) -> Result<BTreeMap<TurnGroupID, TurnGroup>, Box<dyn Error>> {
         let mut results = BTreeMap::new();
         let mut groups: MultiMap<(DirectedRoadID, DirectedRoadID), TurnID> = MultiMap::new();
         for turn in map.get_turns_in_intersection(i) {
@@ -233,11 +236,7 @@ impl TurnGroup {
                 members.iter().map(|t| &map.get_t(*t).geom).collect(),
                 from,
                 to,
-            )
-            .expect(&format!(
-                "Weird turn group geometry near {}",
-                map.get_i(i).orig_id
-            ));
+            )?;
             let turn_types: BTreeSet<TurnType> =
                 members.iter().map(|t| map.get_t(*t).turn_type).collect();
             if turn_types.len() > 1 {
@@ -265,9 +264,11 @@ impl TurnGroup {
             );
         }
         if results.is_empty() {
-            panic!("{} has no TurnGroups!", map.get_i(i).orig_id);
+            return Err(
+                format!("No TurnGroups! Does the intersection have at least 2 roads?").into(),
+            );
         }
-        results
+        Ok(results)
     }
 
     // Polyline points FROM intersection