diff --git a/pavement_parking/src/census_areas.rs b/pavement_parking/src/census_areas.rs
index 8b3a3f6..5bd62a5 100644
--- a/pavement_parking/src/census_areas.rs
+++ b/pavement_parking/src/census_areas.rs
@@ -10,6 +10,8 @@ use geojson::{Feature, FeatureWriter, Value};
 use indicatif::{ProgressBar, ProgressStyle};
 use rstar::{primitives::GeomWithData, RTree, RTreeObject};
 
+use crate::Class;
+
 pub struct CensusAreas {
     rtree: RTree<GeomWithData<Polygon, String>>,
     info: HashMap<String, CensusArea>,
@@ -76,13 +78,13 @@ impl CensusAreas {
         &mut self,
         geom: &LineString,
         average_rating: &str,
-        road_class: &str,
+        class: Class,
     ) -> Result<(Option<String>, f64)> {
         // For each output area, sum the kerb length where it is possible to park a car.
         // Calculate the parkable kerb length per car in the area.
 
         // Estimate the length of the kerb where it is possible to park a car
-        let parkable_length = parkable_kerb_length(geom, average_rating, road_class);
+        let parkable_length = parkable_kerb_length(geom, average_rating, class);
 
         // Assign each road to exactly one output area. If it intersects multiple output areas,
         // it can be assigned by arbitrary but repeatable method.
@@ -122,7 +124,7 @@ impl CensusAreas {
     }
 }
 
-fn parkable_kerb_length(geom: &LineString, rating: &str, class: &str) -> f64 {
+fn parkable_kerb_length(geom: &LineString, rating: &str, class: Class) -> f64 {
     // Returns the length of the kerb where it is possible to park a car
     // i.e. not on a junction or a pedestrian crossing, etc.
     // This attempts to implement the table of proposed interventions in
@@ -136,10 +138,8 @@ fn parkable_kerb_length(geom: &LineString, rating: &str, class: &str) -> f64 {
         "green" => 2.0 * raw_length,
         "amber" => raw_length,
         "red" => match class {
-            "A Road" => 0.0,
-            "B Road" | "Classified Unnumbered" | "Unclassified" => raw_length,
-            "Unknown" | "Not Classified" => raw_length,
-            _ => panic!("Unknown class {class}"),
+            Class::A => 0.0,
+            Class::B | Class::C | Class::Unclassified => raw_length,
         },
         "TODO" => raw_length,
         _ => panic!("Unknown rating {rating}"),
diff --git a/pavement_parking/src/main.rs b/pavement_parking/src/main.rs
index 9326e2b..a8b062a 100644
--- a/pavement_parking/src/main.rs
+++ b/pavement_parking/src/main.rs
@@ -1,6 +1,6 @@
 use std::io::BufWriter;
 
-use anyhow::{bail, Result};
+use anyhow::Result;
 use fs_err::File;
 use gdal::vector::LayerAccess;
 use gdal::Dataset;
@@ -9,7 +9,7 @@ use indicatif::{ProgressBar, ProgressStyle};
 
 use crate::boundaries::Boundaries;
 use crate::census_areas::CensusAreas;
-use crate::roads::Road;
+use crate::roads::{Class, Road};
 
 mod boundaries;
 mod census_areas;
@@ -68,9 +68,9 @@ fn handle_road(
     };
 
     let average_rating_inc_pavements =
-        rating(&road.class, road.road_average + road.pavement_average)?;
-    let average_rating_exc_pavements = rating(&road.class, road.road_average)?;
-    let minimum_rating = rating(&road.class, road.road_minimum)?;
+        rating(road.class, road.road_average + road.pavement_average)?;
+    let average_rating_exc_pavements = rating(road.class, road.road_average)?;
+    let minimum_rating = rating(road.class, road.road_minimum)?;
 
     let rating_change = if average_rating_inc_pavements == average_rating_exc_pavements {
         "no_change"
@@ -81,7 +81,7 @@ fn handle_road(
     let (output_area_geoid, parkable_length) = census_areas.aggregate_kerb_length_per_oa(
         &road.geom,
         &average_rating_exc_pavements,
-        &road.class,
+        road.class,
     )?;
 
     // TODO Use average_rating_exc_pavements for now
@@ -101,18 +101,18 @@ fn handle_road(
         output_area_geoid.unwrap_or("NONE".to_string()),
     );
     output_line.set_property("rating_change", rating_change);
-    output_line.set_property("class", road.class);
+    output_line.set_property("class", format!("{:?}", road.class));
     output_line.set_property("direction", road.direction);
     writer.write_feature(&output_line)?;
 
     Ok(())
 }
 
-fn rating(class: &str, width: f64) -> Result<&'static str> {
+fn rating(class: Class, width: f64) -> Result<&'static str> {
     // See https://www.ordnancesurvey.co.uk/documents/os-open-roads-user-guide.pdf page 22 for the
     // cases. The width thresholds come from a TBD table.
     match class {
-        "A Road" | "B Road" => Ok(if width >= 11.8 {
+        Class::A | Class::B => Ok(if width >= 11.8 {
             "green"
         } else if width >= 10.4 {
             "amber"
@@ -120,8 +120,7 @@ fn rating(class: &str, width: f64) -> Result<&'static str> {
             "red"
         }),
 
-        // Note "Classified Unnumbered" is how OS calls C Roads
-        "Classified Unnumbered" | "Unclassified" => Ok(if width >= 9.0 {
+        Class::C | Class::Unclassified => Ok(if width >= 9.0 {
             "green"
         } else if width >= 7.5 {
             "amber"
@@ -129,10 +128,5 @@ fn rating(class: &str, width: f64) -> Result<&'static str> {
             // TODO Table doesn't handle [7, 7.5]
             "red"
         }),
-
-        // TODO Need to see what these are
-        "Unknown" | "Not Classified" => Ok("TODO"),
-
-        _ => bail!("Unknown roadclassification {class}"),
     }
 }
diff --git a/pavement_parking/src/roads.rs b/pavement_parking/src/roads.rs
index 9aa191b..e06bb25 100644
--- a/pavement_parking/src/roads.rs
+++ b/pavement_parking/src/roads.rs
@@ -3,7 +3,7 @@ use geo::{Coord, LineString, MapCoordsInPlace};
 
 pub struct Road {
     pub geom: LineString,
-    pub class: String,
+    pub class: Class,
     pub road_average: f64,
     pub road_minimum: f64,
     /// Assume that where there are pavements on both sides of the road, then this value is the sum
@@ -12,16 +12,32 @@ pub struct Road {
     pub direction: String,
 }
 
+#[derive(Clone, Copy, Debug)]
+pub enum Class {
+    A,
+    B,
+    C,
+    Unclassified,
+}
+
 impl Road {
     /// Parse data about one road from the input gpkg. `None` means to skip this road.
     pub fn new(input: gdal::vector::Feature) -> Result<Option<Self>> {
         let Some(class) = input.field_as_string_by_name("roadclassification")? else {
             bail!("Missing roadclassification");
         };
-        // Skip roads that shouldn't be analyzed for pavement parking
-        if class == "Motorway" {
-            return Ok(None);
-        }
+        let class = match class.as_str() {
+            "A Road" => Class::A,
+            "B Road" => Class::B,
+            "Classified Unnumbered" => Class::C,
+            "Unclassified" => Class::Unclassified,
+
+            // Skip roads that shouldn't be analyzed for pavement parking
+            "Motorway" | "Unknown" | "Not Classified" => {
+                return Ok(None);
+            }
+            _ => bail!("Unknown roadclassification {class}"),
+        };
 
         let mut geom: LineString = input.geometry().unwrap().to_geo()?.try_into()?;
         // Remove unnecessary precision
diff --git a/pavement_parking/web/src/App.svelte b/pavement_parking/web/src/App.svelte
index f38b03b..bc4823a 100644
--- a/pavement_parking/web/src/App.svelte
+++ b/pavement_parking/web/src/App.svelte
@@ -11,7 +11,7 @@
   } from "svelte-maplibre";
   import PavementLayers from "./PavementLayers.svelte";
   import SummaryLayers from "./SummaryLayers.svelte";
-  import StreetFilters from "./StreetFilters.svelte";
+  import RoadFilters from "./RoadFilters.svelte";
   import OutputAreas from "./OutputAreas.svelte";
   import About from "./About.svelte";
   import { defaultFilters, type Mode } from "./types";
@@ -20,8 +20,8 @@
     ? undefined
     : ([-5.96, 49.89, 2.31, 55.94] as LngLatBoundsLike);
 
-  let show: Mode = "streets";
-  let streetFilters = defaultFilters;
+  let show: Mode = "roads";
+  let roadFilters = defaultFilters;
 
   let params = new URLSearchParams(window.location.search);
   let pavementsUrl = params.get("data") || "";
@@ -60,8 +60,8 @@
       <fieldset>
         <legend>Show:</legend>
         <label>
-          <input type="radio" value="streets" bind:group={show} />
-          Streets
+          <input type="radio" value="roads" bind:group={show} />
+          Roads
         </label>
         <label>
           <input type="radio" value="lad-summary" bind:group={show} />
@@ -77,11 +77,11 @@
         </label>
       </fieldset>
 
-      {#if show == "streets"}
+      {#if show == "roads"}
         {#if zoom >= 10}
-          <StreetFilters bind:filters={streetFilters} />
+          <RoadFilters bind:filters={roadFilters} />
         {:else}
-          <p>Zoom in more to see streets</p>
+          <p>Zoom in more to see roads</p>
         {/if}
       {/if}
     </div>
@@ -97,11 +97,11 @@
 
         {#if pavementsUrl.endsWith(".geojson")}
           <GeoJSON data={pavementsUrl} generateId>
-            <PavementLayers {show} {streetFilters} sourceLayer={undefined} />
+            <PavementLayers {show} {roadFilters} sourceLayer={undefined} />
           </GeoJSON>
         {:else if pavementsUrl.endsWith(".pmtiles")}
           <VectorTileSource url={`pmtiles://${pavementsUrl}`}>
-            <PavementLayers {show} {streetFilters} sourceLayer="pavements" />
+            <PavementLayers {show} {roadFilters} sourceLayer="pavements" />
           </VectorTileSource>
         {/if}
 
diff --git a/pavement_parking/web/src/PavementLayers.svelte b/pavement_parking/web/src/PavementLayers.svelte
index 23a2619..72523e9 100644
--- a/pavement_parking/web/src/PavementLayers.svelte
+++ b/pavement_parking/web/src/PavementLayers.svelte
@@ -5,7 +5,7 @@
   import type { ExpressionSpecification } from "maplibre-gl";
 
   export let show: Mode;
-  export let streetFilters: Filters;
+  export let roadFilters: Filters;
   export let sourceLayer: string | undefined;
 
   function makeFilter(f: Filters): ExpressionSpecification {
@@ -30,13 +30,13 @@
 
 <LineLayer
   {sourceLayer}
-  filter={makeFilter(streetFilters)}
-  layout={{ visibility: show == "streets" ? "visible" : "none" }}
+  filter={makeFilter(roadFilters)}
+  layout={{ visibility: show == "roads" ? "visible" : "none" }}
   manageHoverState
   paint={{
     "line-width": hoverStateFilter(5, 10),
     "line-color": constructMatchExpression(
-      ["get", streetFilters.useRating],
+      ["get", roadFilters.useRating],
       {
         green: colors.green,
         amber: colors.amber,
@@ -50,7 +50,7 @@
 >
   <Popup openOn="hover" let:data popupClass="popup">
     {#if data?.properties}
-      <h1>{data.properties.class} street</h1>
+      <h1>{data.properties.class} road</h1>
       <p>Direction: {data.properties.direction}</p>
       <p>
         Average road width {data.properties.average_width}, rating {data
diff --git a/pavement_parking/web/src/StreetFilters.svelte b/pavement_parking/web/src/RoadFilters.svelte
similarity index 91%
rename from pavement_parking/web/src/StreetFilters.svelte
rename to pavement_parking/web/src/RoadFilters.svelte
index d5b2b80..d21f42e 100644
--- a/pavement_parking/web/src/StreetFilters.svelte
+++ b/pavement_parking/web/src/RoadFilters.svelte
@@ -3,14 +3,7 @@
 
   export let filters: Filters;
 
-  let classes = [
-    "A Road",
-    "B Road",
-    "Classified Unnumbered",
-    "Unclassified",
-    "Unknown",
-    "Not Classified",
-  ] as const;
+  let classes = ["A", "B", "C", "Unclassified"] as const;
 </script>
 
 <fieldset>
diff --git a/pavement_parking/web/src/types.ts b/pavement_parking/web/src/types.ts
index 401279f..3991a9d 100644
--- a/pavement_parking/web/src/types.ts
+++ b/pavement_parking/web/src/types.ts
@@ -1,4 +1,4 @@
-export type Mode = "streets" | "lad-summary" | "ca-summary" | "census-area";
+export type Mode = "roads" | "lad-summary" | "ca-summary" | "census-area";
 
 export interface Filters {
   useRating: "average_rating" | "rating_change" | "minimum_rating";
@@ -9,12 +9,10 @@ export interface Filters {
     no_change: boolean;
   };
   showClasses: {
-    "A Road": boolean;
-    "B Road": boolean;
-    "Classified Unnumbered": boolean;
+    A: boolean;
+    B: boolean;
+    C: boolean;
     Unclassified: boolean;
-    Unknown: boolean;
-    "Not Classified": boolean;
   };
   showDirections: {
     both: boolean;
@@ -31,12 +29,10 @@ export const defaultFilters: Filters = {
     no_change: true,
   },
   showClasses: {
-    "A Road": true,
-    "B Road": true,
-    "Classified Unnumbered": true,
+    A: true,
+    B: true,
+    C: true,
     Unclassified: true,
-    Unknown: true,
-    "Not Classified": true,
   },
   showDirections: {
     both: true,