diff --git a/Cargo.lock b/Cargo.lock
index f14ede782c..9900c59b5d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2048,6 +2048,7 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.106 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
diff --git a/convert_osm/src/srtm.rs b/convert_osm/src/srtm.rs
index 0a699eb918..ea9981d8c0 100644
--- a/convert_osm/src/srtm.rs
+++ b/convert_osm/src/srtm.rs
@@ -39,8 +39,8 @@ impl Elevation {
         // TODO assert the (lon, lat) match the offsets
         // TODO not tons of confidence in any of this.
         // TODO interpolate from the 4 matching tiles?
-        let x = ((pt.longitude - self.lon_offset).abs() * (GRID_DIM as f64)) as usize;
-        let y = ((pt.latitude - self.lat_offset).abs() * (GRID_DIM as f64)) as usize;
+        let x = ((pt.x() - self.lon_offset).abs() * (GRID_DIM as f64)) as usize;
+        let y = ((pt.y() - self.lat_offset).abs() * (GRID_DIM as f64)) as usize;
         let i = x + (y * GRID_DIM);
         Distance::meters(f64::from(self.data[i]))
     }
diff --git a/geom/Cargo.toml b/geom/Cargo.toml
index db0f55315f..da7bf69c85 100644
--- a/geom/Cargo.toml
+++ b/geom/Cargo.toml
@@ -12,7 +12,7 @@ geo-booleanop = "0.2.0"
 geo-offset = "0.1.0"
 histogram = "0.6.9"
 instant = "0.1.2"
-ordered-float = "1.0.1"
+ordered-float = { version = "1.0.1", features=["serde"] }
 polylabel = { git = "https://github.com/urschrei/polylabel-rs" }
 serde = "1.0.98"
 serde_derive = "1.0.98"
diff --git a/geom/src/bounds.rs b/geom/src/bounds.rs
index e37475f5a5..fffe52f476 100644
--- a/geom/src/bounds.rs
+++ b/geom/src/bounds.rs
@@ -101,17 +101,17 @@ impl GPSBounds {
     }
 
     pub fn update(&mut self, pt: LonLat) {
-        self.min_lon = self.min_lon.min(pt.longitude);
-        self.max_lon = self.max_lon.max(pt.longitude);
-        self.min_lat = self.min_lat.min(pt.latitude);
-        self.max_lat = self.max_lat.max(pt.latitude);
+        self.min_lon = self.min_lon.min(pt.x());
+        self.max_lon = self.max_lon.max(pt.x());
+        self.min_lat = self.min_lat.min(pt.y());
+        self.max_lat = self.max_lat.max(pt.y());
     }
 
     pub fn contains(&self, pt: LonLat) -> bool {
-        pt.longitude >= self.min_lon
-            && pt.longitude <= self.max_lon
-            && pt.latitude >= self.min_lat
-            && pt.latitude <= self.max_lat
+        pt.x() >= self.min_lon
+            && pt.x() <= self.max_lon
+            && pt.y() >= self.min_lat
+            && pt.y() <= self.max_lat
     }
 
     // TODO cache this
diff --git a/geom/src/gps.rs b/geom/src/gps.rs
index 61ddac5f64..e69b3f1f13 100644
--- a/geom/src/gps.rs
+++ b/geom/src/gps.rs
@@ -4,27 +4,35 @@ use serde_derive::{Deserialize, Serialize};
 use std::fmt;
 
 // longitude is x, latitude is y
-#[derive(Copy, Clone, PartialEq, Debug, Serialize, Deserialize)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Serialize, Deserialize)]
 pub struct LonLat {
-    pub longitude: f64,
-    pub latitude: f64,
+    longitude: NotNan<f64>,
+    latitude: NotNan<f64>,
 }
 
 impl LonLat {
     pub fn new(lon: f64, lat: f64) -> LonLat {
         LonLat {
-            longitude: lon,
-            latitude: lat,
+            longitude: NotNan::new(lon).unwrap(),
+            latitude: NotNan::new(lat).unwrap(),
         }
     }
 
+    pub fn x(self) -> f64 {
+        self.longitude.into_inner()
+    }
+
+    pub fn y(self) -> f64 {
+        self.latitude.into_inner()
+    }
+
     pub fn gps_dist_meters(self, other: LonLat) -> Distance {
         // Haversine distance
         let earth_radius_m = 6_371_000.0;
-        let lon1 = self.longitude.to_radians();
-        let lon2 = other.longitude.to_radians();
-        let lat1 = self.latitude.to_radians();
-        let lat2 = other.latitude.to_radians();
+        let lon1 = self.x().to_radians();
+        let lon2 = other.x().to_radians();
+        let lat1 = self.y().to_radians();
+        let lat2 = other.y().to_radians();
 
         let delta_lat = lat2 - lat1;
         let delta_lon = lon2 - lon1;
@@ -37,21 +45,17 @@ impl LonLat {
 
     // Pretty meaningless units, for comparing distances very roughly
     pub fn fast_dist(self, other: LonLat) -> NotNan<f64> {
-        NotNan::new(
-            (self.longitude - other.longitude).powi(2) + (self.latitude - other.latitude).powi(2),
-        )
-        .unwrap()
+        NotNan::new((self.x() - other.x()).powi(2) + (self.y() - other.y()).powi(2)).unwrap()
     }
 
     pub(crate) fn approx_eq(self, other: LonLat) -> bool {
         let epsilon = 1e-8;
-        (self.longitude - other.longitude).abs() < epsilon
-            && (self.latitude - other.latitude).abs() < epsilon
+        (self.x() - other.x()).abs() < epsilon && (self.y() - other.y()).abs() < epsilon
     }
 }
 
 impl fmt::Display for LonLat {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "LonLat({0}, {1})", self.longitude, self.latitude)
+        write!(f, "LonLat({0}, {1})", self.x(), self.y())
     }
 }
diff --git a/geom/src/pt.rs b/geom/src/pt.rs
index d000b21d77..09d617a0f5 100644
--- a/geom/src/pt.rs
+++ b/geom/src/pt.rs
@@ -50,10 +50,10 @@ impl Pt2D {
             (pt.x(), pt.y())
         };
 
-        let x = (gps.longitude - b.min_lon) / (b.max_lon - b.min_lon) * width;
+        let x = (gps.x() - b.min_lon) / (b.max_lon - b.min_lon) * width;
         // Invert y, so that the northernmost latitude is 0. Screen drawing order, not Cartesian
         // grid.
-        let y = height - ((gps.latitude - b.min_lat) / (b.max_lat - b.min_lat) * height);
+        let y = height - ((gps.y() - b.min_lat) / (b.max_lat - b.min_lat) * height);
         Pt2D::new(x, y)
     }
 
diff --git a/map_model/src/neighborhood.rs b/map_model/src/neighborhood.rs
index e6adcf8eb6..e56f0dd8dd 100644
--- a/map_model/src/neighborhood.rs
+++ b/map_model/src/neighborhood.rs
@@ -49,15 +49,11 @@ impl NeighborhoodBuilder {
         writeln!(f, "{}", self.name)?;
         writeln!(f, "1")?;
         for gps in &self.points {
-            writeln!(f, "     {}    {}", gps.longitude, gps.latitude)?;
+            writeln!(f, "     {}    {}", gps.x(), gps.y())?;
         }
         // Have to repeat the first point
         {
-            writeln!(
-                f,
-                "     {}    {}",
-                self.points[0].longitude, self.points[0].latitude
-            )?;
+            writeln!(f, "     {}    {}", self.points[0].x(), self.points[0].y())?;
         }
         writeln!(f, "END")?;
         writeln!(f, "END")?;