diff --git a/convert_osm/src/remove_disconnected.rs b/convert_osm/src/remove_disconnected.rs
index aed397f0c3..62c3703527 100644
--- a/convert_osm/src/remove_disconnected.rs
+++ b/convert_osm/src/remove_disconnected.rs
@@ -55,8 +55,8 @@ pub fn remove_disconnected_roads(map: &mut raw_data::Map, timer: &mut Timer) {
     let mut roads: Vec<raw_data::Road> = Vec::new();
     for (idx, r) in map.roads.iter().enumerate() {
         if remove_roads.contains(&idx) {
-            next_roads.remove(r.first_pt(), idx);
-            next_roads.remove(r.last_pt(), idx);
+            next_roads.remove(r.first_pt().to_hashable(), idx);
+            next_roads.remove(r.last_pt().to_hashable(), idx);
         } else {
             roads.push(r.clone());
         }
diff --git a/map_model/src/edits.rs b/map_model/src/edits.rs
index 89dde1870e..18107d2b23 100644
--- a/map_model/src/edits.rs
+++ b/map_model/src/edits.rs
@@ -1,3 +1,4 @@
+use abstutil::{deserialize_btreemap, serialize_btreemap};
 use std::collections::BTreeMap;
 use {Lane, LaneType, Road, RoadID};
 
@@ -7,6 +8,10 @@ use {Lane, LaneType, Road, RoadID};
 pub struct RoadEdits {
     pub edits_name: String,
     // TODO detect when we wind up editing back to the original thing
+    #[serde(
+        serialize_with = "serialize_btreemap",
+        deserialize_with = "deserialize_btreemap"
+    )]
     pub(crate) roads: BTreeMap<RoadID, RoadEdit>,
 }
 
diff --git a/map_model/src/map.rs b/map_model/src/map.rs
index 16a79bf73a..b34b878a54 100644
--- a/map_model/src/map.rs
+++ b/map_model/src/map.rs
@@ -1,7 +1,7 @@
 // Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
 
 use abstutil;
-use abstutil::{Error, Timer};
+use abstutil::{deserialize_btreemap, serialize_btreemap, Error, Timer};
 use edits::RoadEdits;
 use geom::{Bounds, GPSBounds, HashablePt2D, PolyLine, Pt2D};
 use make;
@@ -20,9 +20,17 @@ pub struct Map {
     roads: Vec<Road>,
     lanes: Vec<Lane>,
     intersections: Vec<Intersection>,
+    #[serde(
+        serialize_with = "serialize_btreemap",
+        deserialize_with = "deserialize_btreemap"
+    )]
     turns: BTreeMap<TurnID, Turn>,
     buildings: Vec<Building>,
     parcels: Vec<Parcel>,
+    #[serde(
+        serialize_with = "serialize_btreemap",
+        deserialize_with = "deserialize_btreemap"
+    )]
     bus_stops: BTreeMap<BusStopID, BusStop>,
     bus_routes: Vec<BusRoute>,
     areas: Vec<Area>,
diff --git a/tests/src/map_conversion.rs b/tests/src/map_conversion.rs
index bd2cb9900b..6742bd97f8 100644
--- a/tests/src/map_conversion.rs
+++ b/tests/src/map_conversion.rs
@@ -1,10 +1,11 @@
 use abstutil;
 use convert_osm;
+use map_model;
 use runner::TestRunner;
 
 pub fn run(t: &mut TestRunner) {
     t.run_slow(
-        "convert_twice",
+        "convert_osm_twice",
         Box::new(|_| {
             let flags = convert_osm::Flags {
                 osm: "../data/input/montlake.osm".to_string(),
@@ -14,7 +15,7 @@ pub fn run(t: &mut TestRunner) {
                 parking_shapes: "../data/shapes/blockface".to_string(),
                 gtfs: "../data/input/google_transit_2018_18_08".to_string(),
                 neighborhoods: "../data/input/neighborhoods.geojson".to_string(),
-                output: "convert_twice".to_string(),
+                output: "convert_osm_twice".to_string(),
             };
 
             let map1 = convert_osm::convert(&flags, &mut abstutil::Timer::new("convert map"));
@@ -28,4 +29,27 @@ pub fn run(t: &mut TestRunner) {
             }
         }),
     );
+
+    t.run_slow(
+        "raw_to_map_twice",
+        Box::new(|_| {
+            let map1 = map_model::Map::new(
+                "../data/raw_maps/montlake.abst",
+                map_model::RoadEdits::new(),
+                &mut abstutil::Timer::new("raw to map"),
+            ).unwrap();
+            let map2 = map_model::Map::new(
+                "../data/raw_maps/montlake.abst",
+                map_model::RoadEdits::new(),
+                &mut abstutil::Timer::new("raw to map"),
+            ).unwrap();
+
+            if abstutil::to_json(&map1) != abstutil::to_json(&map2) {
+                // TODO tmp files
+                abstutil::write_json("map1.json", &map1).unwrap();
+                abstutil::write_json("map2.json", &map2).unwrap();
+                panic!("map1.json and map2.json differ");
+            }
+        }),
+    );
 }