fix location of stop signs / signals, based on bad center

editor/src/render/intersection.rs

@@ -20,8 +20,13 @@ pub struct DrawIntersection {
 
 impl DrawIntersection {
     pub fn new(inter: &Intersection, map: &Map) -> DrawIntersection {
+        // Don't skew the center towards the repeated point
+        let mut pts = inter.polygon.clone();
+        pts.pop();
+        let center = Pt2D::center(&pts);
+
         DrawIntersection {
-            center: Pt2D::center(&inter.polygon),
+            center,
             id: inter.id,
             polygon: Polygon::new(&inter.polygon),
             crosswalks: calculate_crosswalks(inter, map),

map_model/src/make/intersections.rs

@@ -54,7 +54,8 @@ pub fn intersection_polygon(
         let angle_diff = (pl1.last_line().angle().opposite().normalized_degrees()
             - pl2.last_line().angle().normalized_degrees()).abs();
 
-        if angle_diff > 5.0 {
+        // TODO A tuning challenge. :)
+        if angle_diff > 15.0 {
             // The easy case!
             if let Some(hit) = pl1.intersection(&pl2) {
                 endpoints.push(hit);