diff --git a/Cargo.lock b/Cargo.lock
index 603df94772..12418b652c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -124,9 +124,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.41"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15af2628f6890fe2609a3b91bef4c83450512802e59489f9c1cb1fa5df064a61"
+checksum = "224afbd727c3d6e4b90103ece64b8d1b67fbb1973b1046c2281eed3f3803f800"
 
 [[package]]
 name = "approx"
@@ -713,6 +713,7 @@ dependencies = [
  "kml",
  "log",
  "osm2streets",
+ "popgetter",
  "raw_map",
  "serde",
  "streets_reader",
@@ -1509,9 +1510,9 @@ dependencies = [
 
 [[package]]
 name = "fs-err"
-version = "2.6.0"
+version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ebd3504ad6116843b8375ad70df74e7bfe83cac77a1f3fe73200c844d43bfe0"
+checksum = "0845fa252299212f0389d64ba26f34fa32cfe41588355f21ed507c59a0f64541"
 
 [[package]]
 name = "futures"
@@ -2765,6 +2766,7 @@ dependencies = [
  "md5",
  "osm2streets",
  "petgraph",
+ "popgetter",
  "rand",
  "rand_xorshift",
  "raw_map",
@@ -3427,6 +3429,20 @@ dependencies = [
  "synthpop",
 ]
 
+[[package]]
+name = "popgetter"
+version = "0.1.0"
+source = "git+https://github.com/dabreegster/popgetter/#20eb9d3facae9f0f01394fd5493a0adfbc8578f5"
+dependencies = [
+ "anyhow",
+ "fs-err",
+ "geo",
+ "geo-types",
+ "geojson",
+ "serde",
+ "topojson",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.10"
@@ -3591,6 +3607,7 @@ dependencies = [
  "abstutil",
  "geom",
  "osm2streets",
+ "popgetter",
  "serde",
  "strum",
  "strum_macros",
@@ -4591,6 +4608,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "topojson"
+version = "0.5.1"
+source = "git+https://github.com/dabreegster/topojson?branch=update#f962c7b3ae372925a74c327d90ee73ff487d8a6b"
+dependencies = [
+ "geojson",
+ "log",
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "tower-service"
 version = "0.3.1"
diff --git a/Cargo.toml b/Cargo.toml
index 5a54f3f27e..94a91180ea 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,12 +37,12 @@ opt-level = 3
 # Specify the versions for common dependencies just once here, instead of
 # repeating in a bunch of crates
 [workspace.dependencies]
-anyhow = "1.0.38"
+anyhow = "1.0.69"
 bincode = "1.3.1"
 colorous = "1.0.9"
 contour = "0.7.0"
 csv = "1.2.0"
-fs-err = "2.6.0"
+fs-err = "2.9.0"
 geo = "0.24.0"
 geojson = { version = "0.24.0", features = ["geo-types"] }
 getrandom = "0.2.3"
diff --git a/convert_osm/Cargo.toml b/convert_osm/Cargo.toml
index d4ad05d80e..6185c18417 100644
--- a/convert_osm/Cargo.toml
+++ b/convert_osm/Cargo.toml
@@ -14,6 +14,7 @@ geom = { path = "../geom" }
 kml = { path = "../kml" }
 log = { workspace = true }
 osm2streets = { git = "https://github.com/a-b-street/osm2streets" }
+popgetter = { git = "https://github.com/dabreegster/popgetter/" }
 raw_map = { path = "../raw_map" }
 serde = { workspace = true }
 streets_reader = { git = "https://github.com/a-b-street/osm2streets" }
diff --git a/convert_osm/src/lib.rs b/convert_osm/src/lib.rs
index b475b6d59a..09517f95ad 100644
--- a/convert_osm/src/lib.rs
+++ b/convert_osm/src/lib.rs
@@ -152,6 +152,12 @@ pub fn convert(
         gtfs::import(&mut map).unwrap();
     }
 
+    timer.start("Add census data");
+    if let Err(err) = add_census(&mut map) {
+        error!("Skipping census data: {err}");
+    }
+    timer.stop("Add census data");
+
     if map.name == MapName::new("gb", "bristol", "east") {
         bristol_hack(&mut map);
     }
@@ -379,3 +385,23 @@ fn filter_crosswalks(
         }
     }
 }
+
+fn add_census(map: &mut RawMap) -> Result<()> {
+    // TODO Fixed to one area right now. Assumes the file exists.
+    let input_path = "data/input/shared/popgetter/england.topojson";
+    let boundary = map
+        .streets
+        .boundary_polygon
+        .to_geo_wgs84(&map.streets.gps_bounds);
+    for (geo_polygon, census_zone) in popgetter::clip_zones(input_path, boundary)? {
+        match Polygon::from_geo_wgs84(geo_polygon, &map.streets.gps_bounds) {
+            Ok(polygon) => {
+                map.census_zones.push((polygon, census_zone));
+            }
+            Err(err) => {
+                warn!("Skipping census zone {}: {}", census_zone.id, err);
+            }
+        }
+    }
+    Ok(())
+}
diff --git a/data/MANIFEST.json b/data/MANIFEST.json
index 777d771c0e..03e5c52740 100644
--- a/data/MANIFEST.json
+++ b/data/MANIFEST.json
@@ -216,8 +216,8 @@
       "compressed_size_bytes": 13642164
     },
     "data/input/fr/paris/raw_maps/center.bin": {
-      "checksum": "6f2811ae79e8b71cb2f596fb456d7dfe",
-      "uncompressed_size_bytes": 25065354,
+      "checksum": "896d1a1ae5a7dacd63d32b5fd6d931f6",
+      "uncompressed_size_bytes": 25065338,
       "compressed_size_bytes": 6777329
     },
     "data/input/fr/paris/raw_maps/east.bin": {
@@ -1530,6 +1530,11 @@
       "uncompressed_size_bytes": 272419737,
       "compressed_size_bytes": 271888733
     },
+    "data/input/shared/popgetter/england.topojson": {
+      "checksum": "a894795a5bfadf60899f4ba892a32789",
+      "uncompressed_size_bytes": 52802533,
+      "compressed_size_bytes": 7976809
+    },
     "data/input/shared/wu03ew_v2.csv": {
       "checksum": "6614880a64e448b4e9a7255ab5355d00",
       "uncompressed_size_bytes": 108977615,
diff --git a/geom/src/polygon.rs b/geom/src/polygon.rs
index 104fb4d41f..44c82c6172 100644
--- a/geom/src/polygon.rs
+++ b/geom/src/polygon.rs
@@ -2,7 +2,9 @@ use std::collections::BTreeMap;
 use std::fmt;
 
 use anyhow::Result;
-use geo::{Area, BooleanOps, Contains, ConvexHull, Intersects, SimplifyVwPreserve};
+use geo::{
+    Area, BooleanOps, Contains, ConvexHull, Intersects, MapCoordsInPlace, SimplifyVwPreserve,
+};
 use serde::{Deserialize, Serialize};
 
 use crate::{
@@ -410,8 +412,6 @@ impl Polygon {
 
     /// Optionally map the world-space points back to GPS.
     pub fn to_geojson(&self, gps: Option<&GPSBounds>) -> geojson::Geometry {
-        use geo::MapCoordsInPlace;
-
         let mut geom: geo::Geometry = self.to_geo().into();
         if let Some(ref gps_bounds) = gps {
             geom.map_coords_in_place(|c| {
@@ -498,6 +498,24 @@ impl Polygon {
     fn to_geo(&self) -> geo::Polygon {
         self.clone().into()
     }
+
+    /// Convert to `geo` and also map from world-space to WGS84
+    pub fn to_geo_wgs84(&self, gps_bounds: &GPSBounds) -> geo::Polygon<f64> {
+        let mut p = self.to_geo();
+        p.map_coords_in_place(|c| {
+            let gps = Pt2D::new(c.x, c.y).to_gps(gps_bounds);
+            (gps.x(), gps.y()).into()
+        });
+        p
+    }
+
+    pub fn from_geo_wgs84(mut polygon: geo::Polygon<f64>, gps_bounds: &GPSBounds) -> Result<Self> {
+        polygon.map_coords_in_place(|c| {
+            let pt = LonLat::new(c.x, c.y).to_pt(gps_bounds);
+            (pt.x(), pt.y()).into()
+        });
+        polygon.try_into()
+    }
 }
 
 impl fmt::Display for Polygon {
diff --git a/map_model/Cargo.toml b/map_model/Cargo.toml
index 1d991dcb44..1912819e8f 100644
--- a/map_model/Cargo.toml
+++ b/map_model/Cargo.toml
@@ -17,6 +17,7 @@ log = { workspace = true }
 lyon = "1.0.1"
 md5 = "0.7.0"
 petgraph = { version = "0.6.3", features=["serde-1"] }
+popgetter = { git = "https://github.com/dabreegster/popgetter/" }
 rand = { workspace = true }
 rand_xorshift = { workspace = true }
 raw_map = { path = "../raw_map" }
diff --git a/map_model/src/lib.rs b/map_model/src/lib.rs
index 4f4a3ef345..5278046e3c 100644
--- a/map_model/src/lib.rs
+++ b/map_model/src/lib.rs
@@ -30,6 +30,7 @@ extern crate log;
 
 use std::collections::BTreeMap;
 
+use popgetter::CensusZone;
 use serde::{Deserialize, Serialize};
 
 use abstio::MapName;
@@ -115,6 +116,7 @@ pub struct Map {
     routing_params: RoutingParams,
     // Not the source of truth, just cached.
     zones: Vec<Zone>,
+    census_zones: Vec<(Polygon, CensusZone)>,
 
     name: MapName,
 
diff --git a/map_model/src/make/mod.rs b/map_model/src/make/mod.rs
index b5a9df87c9..7a09f51af0 100644
--- a/map_model/src/make/mod.rs
+++ b/map_model/src/make/mod.rs
@@ -54,6 +54,7 @@ impl Map {
             areas: Vec::new(),
             parking_lots: Vec::new(),
             zones: Vec::new(),
+            census_zones: raw.census_zones.clone(),
             boundary_polygon: raw.streets.boundary_polygon.clone(),
             stop_signs: BTreeMap::new(),
             traffic_signals: BTreeMap::new(),
diff --git a/map_model/src/map.rs b/map_model/src/map.rs
index e9ba1bbff3..605a699860 100644
--- a/map_model/src/map.rs
+++ b/map_model/src/map.rs
@@ -4,6 +4,7 @@ use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque};
 
 use anyhow::Result;
 use petgraph::graphmap::{DiGraphMap, UnGraphMap};
+use popgetter::CensusZone;
 
 use abstio::{CityName, MapName};
 use abstutil::{prettyprint_usize, serialized_size_bytes, MultiMap, Tags, Timer};
@@ -104,6 +105,11 @@ impl Map {
                     self.zones.len(),
                     serialized_size_bytes(&self.zones),
                 ),
+                (
+                    "census_zones",
+                    self.census_zones.len(),
+                    serialized_size_bytes(&self.census_zones),
+                ),
                 ("pathfinder", 1, serialized_size_bytes(&self.pathfinder)),
             ];
             costs.sort_by_key(|(_, _, bytes)| *bytes);
@@ -135,6 +141,7 @@ impl Map {
             areas: Vec::new(),
             parking_lots: Vec::new(),
             zones: Vec::new(),
+            census_zones: Vec::new(),
             boundary_polygon: Ring::must_new(vec![
                 Pt2D::new(0.0, 0.0),
                 Pt2D::new(1.0, 0.0),
@@ -257,6 +264,10 @@ impl Map {
         &self.zones
     }
 
+    pub fn all_census_zones(&self) -> &Vec<(Polygon, CensusZone)> {
+        &self.census_zones
+    }
+
     pub fn maybe_get_r(&self, id: RoadID) -> Option<&Road> {
         self.roads.get(id.0)
     }
diff --git a/map_model/src/pathfind/mod.rs b/map_model/src/pathfind/mod.rs
index 4c5290bfc1..1f1a24ae94 100644
--- a/map_model/src/pathfind/mod.rs
+++ b/map_model/src/pathfind/mod.rs
@@ -193,8 +193,6 @@ pub struct RoutingParams {
     /// TODO The route may cross one of these roads if it's the start or end!
     pub avoid_roads: BTreeSet<RoadID>,
     /// Related to `avoid_roads`, but used as an optimization in map construction
-    // TODO Serialize this normally. In the meantime, safe because the default is indeed empty.
-    #[serde(skip_serializing, skip_deserializing)]
     pub only_use_roads: BTreeSet<RoadID>,
 
     /// Don't allow movements between these roads at all. Only affects vehicle routing, not
diff --git a/raw_map/Cargo.toml b/raw_map/Cargo.toml
index b648c42fa1..5c00ce7079 100644
--- a/raw_map/Cargo.toml
+++ b/raw_map/Cargo.toml
@@ -10,5 +10,6 @@ abstutil = { path = "../abstutil" }
 geom = { path = "../geom" }
 serde = { workspace = true }
 osm2streets = { git = "https://github.com/a-b-street/osm2streets" }
+popgetter = { git = "https://github.com/dabreegster/popgetter/" }
 strum = "0.24.1"
 strum_macros = "0.24.3"
diff --git a/raw_map/src/lib.rs b/raw_map/src/lib.rs
index c523f92419..c16c4d8bab 100644
--- a/raw_map/src/lib.rs
+++ b/raw_map/src/lib.rs
@@ -5,6 +5,7 @@
 use std::collections::BTreeMap;
 
 use osm2streets::{osm, IntersectionID, RoadID, StreetNetwork};
+use popgetter::CensusZone;
 use serde::{Deserialize, Serialize};
 
 use abstio::{CityName, MapName};
@@ -31,6 +32,7 @@ pub struct RawMap {
     pub parking_lots: Vec<RawParkingLot>,
     pub parking_aisles: Vec<(osm::WayID, Vec<Pt2D>)>,
     pub transit_routes: Vec<RawTransitRoute>,
+    pub census_zones: Vec<(Polygon, CensusZone)>,
     #[serde(
         serialize_with = "serialize_btreemap",
         deserialize_with = "deserialize_btreemap"
@@ -74,6 +76,7 @@ impl RawMap {
             parking_lots: Vec::new(),
             parking_aisles: Vec::new(),
             transit_routes: Vec::new(),
+            census_zones: Vec::new(),
             transit_stops: BTreeMap::new(),
             bus_routes_on_roads: MultiMap::new(),
             osm_tags: BTreeMap::new(),