25:["$","title",null,{"children":"Boston bluebikes | Visnu Pitiyanuvath | Observable"}] 4b:Taaf,const inCore = (lat, lng) => lat > 42.30 && lat < 42.42 && lng > -71.20 && lng < -71.03; const routeData = Array.from(routes, (d) => ({...d.toJSON(), trips: Number(d.trips)})) .filter((d) => inCore(d.start_lat, d.start_lng) && inCore(d.end_lat, d.end_lng)); const routeColor = d3.scaleSequentialSqrt([d3.min(routeData, (d) => d.trips), d3.max(routeData, (d) => d.trips)], d3.interpolateYlOrRd); // MapLibre needs its stylesheet if (!document.getElementById("maplibre-css")) { document.head.append(html``); } display(html`

Busiest Bluebikes routes, October 2026

Top station-to-station routes in the Boston core; line width and color show trips. Basemap © OpenStreetMap contributors © CARTO.

`); const mapDiv = display(html`

`); const map = new maplibregl.Map({ container: mapDiv, style: "https://basemaps.cartocdn.com/gl/voyager-gl-style/style.json?key=cb1_56af_1_45c19e2fc865d96d29b78f56", bounds: [[-71.135, 42.335], [-71.045, 42.385]] }); map.addControl(new maplibregl.NavigationControl({showCompass: false})); const mapStatus = await new Promise((resolve) => { map.once("load", () => resolve("loaded")); map.once("error", (e) => resolve("error: " + (e.error?.message ?? e.message))); setTimeout(() => resolve("timeout"), 15000); }); if (mapStatus === "loaded") { map.addSource("routes", { type: "geojson", data: { type: "FeatureCollection", features: routeData.slice().reverse().map((d) => ({ type: "Feature", properties: {origin: d.origin, destination: d.destination, trips: d.trips, color: routeColor(d.trips), width: Math.sqrt(d.trips) / 5 + 1}, geometry: {type: "LineString", coordinates: [[d.start_lng, d.start_lat], [d.end_lng, d.end_lat]]} })) } }); map.addLayer({ id: "routes", type: "line", source: "routes", layout: {"line-cap": "round"}, paint: {"line-color": ["get", "color"], "line-width": ["get", "width"], "line-opacity": 0.85} }); const popup = new maplibregl.Popup({closeButton: false, closeOnClick: false}); map.on("mousemove", "routes", (e) => { map.getCanvas().style.cursor = "pointer"; const p = e.features[0].properties; popup.setLngLat(e.lngLat).setHTML(`${p.origin} → ${p.destination}
${p.trips} trips`).addTo(map); }); map.on("mouseleave", "routes", () => { map.getCanvas().style.cursor = ""; popup.remove(); }); } display(mapStatus); invalidation.then(() => map.remove());4c:T50e,const odData = Array.from(odMatrix, (d) => ({origin: d.origin, destination: d.destination, trips: Number(d.trips)})); // Order stations by total trips involving them (as origin or destination) const stationOrder = d3.sort( d3.rollups(odData.flatMap((d) => [{s: d.origin, n: d.trips}, {s: d.destination, n: d.trips}]), (v) => d3.sum(v, (d) => d.n), (d) => d.s), (a, b) => d3.descending(a[1], b[1]) ).map((d) => d[0]); const shorten = (s) => (s.length > 34 ? s.slice(0, 33) + "…" : s); const odPlot = display(Plot.plot({ title: "Where Bluebikes trips go: origin → destination, October 2026", subtitle: "Trips between the 25 busiest start stations; darker = more trips. Diagonal = trips that start and end at the same station.", width, aspectRatio: 1.5, marginLeft: 230, marginBottom: 190, padding: 0.05, x: {domain: stationOrder, label: null, tickRotate: -60, tickSize: 0, tickFormat: shorten}, y: {domain: stationOrder, label: null, tickSize: 0, tickFormat: shorten}, color: {type: "sqrt", scheme: "YlOrRd", legend: true, label: "Trips (rows = origin, columns = destination)", unknown: "#f4f4f4"}, marks: [ Plot.cell(odData, {x: "destination", y: "origin", fill: "trips", tip: true, title: (d) => `${d.origin} → ${d.destination}\n${d.trips} trips`}) ] }));4d:T49b,const maxTrips = d3.max(horizonData, (d) => d.trips); const nBands = 4; const bandStep = Math.ceil(maxTrips / nBands / 50) * 50; const bandColors = d3.schemeBlues[nBands + 2].slice(2); const horizonPlot = display(Plot.plot({ title: "Bluebikes ridership by time of day: weekday horizon chart, October 2026", subtitle: `Average trips per 15 minutes, one row per weekday. Each darker band stacks another ${bandStep} trips.`, width, height: 360, marginLeft: 80, x: {label: "Time of day", domain: [0, 24], ticks: d3.range(0, 25, 3), tickFormat: (h) => h === 24 ? "" : `${(h % 12) || 12}${h < 12 ? "am" : "pm"}`}, y: {axis: null, domain: [0, bandStep]}, fy: {label: null, domain: dayOrder, padding: 0.05}, marks: [ d3.range(nBands).map((k) => Plot.areaY(horizonData, { x: "hour", y: (d) => d.trips - k * bandStep, fy: "day", fill: bandColors[k], clip: true, curve: "step-after" }) ), Plot.frame({strokeOpacity: 0.1}), Plot.tip(horizonData, Plot.pointerX({x: "hour", y: 0, fy: "day", title: (d) => `${d.day} ${Math.floor(d.hour)}:${String((d.hour % 1) * 60).padStart(2, "0")}\n${d.trips.toFixed(0)} trips (avg)`})) ] }));4e:[{"id":"54a0429e93fdff8ff5af9271b2657af332a5eb7054078630aa961fe929cbd9f7dd9f8e026827caa1a71b03ec71ded16ffcdbb40e84a6342197c66cd8f5807fc3","href":"https://static.observableusercontent.com/files/54a0429e93fdff8ff5af9271b2657af332a5eb7054078630aa961fe929cbd9f7dd9f8e026827caa1a71b03ec71ded16ffcdbb40e84a6342197c66cd8f5807fc3","name":".observable/cache/fetch-38mqpmcjg0teikukrx17rg0aoysr6d47.blob","type":"application/zip","lastModified":1793898529000,"size":31339802}] 47:{"id":"24e51e1f9e4e1c9c","slug":"boston-bluebikes","title":"Boston bluebikes","thumbnail":"1fe04e25b47b25918b18924056c6c7a5a9469c5b1358e6522d889660dc506e70","access_level":"public","create_time":"$D2026-11-10T16:39:26.365Z","update_time":"$D2026-11-10T20:55:28.439Z","view_time":null,"first_public_time":"$D2026-11-10T16:58:02.000Z","has_unpublished_edits":null,"fork":false,"stars":0,"starred":false,"owner":{"type":"team","id":"31b136fdb993b00a","login":"visnup","name":"Visnu Pitiyanuvath","avatar_url":"https://avatars-next.observableusercontent.com/b847c4c49993b1df7599d355f47dc0ad9c2dcf43439ce9e8f3410e6368b3aac9","tier":"pro_2026","bio":"","followed_by_you":false,"follows_you":false},"version":93,"publish_version":93,"role":null,"authored":false,"authors":[{"type":"individual","id":"dbf69c13a14d2f62","login":"visnup","name":"Visnu Pitiyanuvath","avatar_url":"https://avatars-next.observableusercontent.com/b847c4c49993b1df7599d355f47dc0ad9c2dcf43439ce9e8f3410e6368b3aac9","tier":null,"bio":"","followed_by_you":false,"follows_you":false}],"members":[{"type":"team","id":"31b136fdb993b00a","login":"visnup","name":"Visnu Pitiyanuvath","avatar_url":"https://avatars-next.observableusercontent.com/b847c4c49993b1df7599d355f47dc0ad9c2dcf43439ce9e8f3410e6368b3aac9","tier":"pro_2026","role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"titling":"auto","title":"Boston bluebikes","cells":[{"id":1,"value":"# Boston bluebikes","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":12,"value":"$4b","pinned":false,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":11,"value":"SELECT start_station_name AS origin,\n end_station_name AS destination,\n AVG(start_lat) AS start_lat, AVG(start_lng) AS start_lng,\n AVG(end_lat) AS end_lat, AVG(end_lng) AS end_lng,\n COUNT(*) AS trips\nFROM trips\nWHERE start_station_id <> end_station_id\n AND start_lat BETWEEN 42 AND 43 AND end_lat BETWEEN 42 AND 43\n AND start_station_name IS NOT NULL AND end_station_name IS NOT NULL\nGROUP BY 1, 2\nORDER BY trips DESC\nLIMIT 300","pinned":true,"hidden":false,"mode":"sql","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"routes","database":"var:bikedb"},{"id":21,"value":"$4c","pinned":false,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":20,"value":"WITH top_stations AS (\n SELECT start_station_name AS station\n FROM trips\n WHERE start_station_name IS NOT NULL\n GROUP BY 1\n ORDER BY COUNT(*) DESC\n LIMIT 25\n)\nSELECT start_station_name AS origin,\n end_station_name AS destination,\n COUNT(*) AS trips\nFROM trips\nWHERE start_station_name IN (SELECT station FROM top_stations)\n AND end_station_name IN (SELECT station FROM top_stations)\nGROUP BY 1, 2","pinned":true,"hidden":false,"mode":"sql","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"odMatrix","database":"var:bikedb"},{"id":10,"value":"SELECT start_station_name AS station,\n COUNT(*) AS trips,\n ROUND(AVG(epoch(ended_at - started_at)) / 60, 1) AS avg_minutes\nFROM trips\nGROUP BY 1\nORDER BY trips DESC\nLIMIT 10","pinned":true,"hidden":false,"mode":"sql","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"topStations","database":"var:bikedb"},{"id":19,"value":"const maplibregl = await new Promise((resolve, reject) => {\n if (window.maplibregl) return resolve(window.maplibregl);\n const script = document.createElement(\"script\");\n script.src = \"https://unpkg.com/maplibre-gl@5/dist/maplibre-gl.js\";\n script.onload = () => resolve(window.maplibregl);\n script.onerror = () => reject(new Error(\"Failed to load maplibre-gl\"));\n document.head.append(script);\n});","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"const zresp = await fetch(\n \"https://s3.amazonaws.com/hubway-data/202610-bluebikes-tripdata.zip\",\n {proxy: true, cache: true}\n);\nif (!zresp.ok) throw new Error(\"fetch failed \" + zresp.status);\nconst zbuf = await zresp.arrayBuffer();\ndisplay(zbuf.byteLength);","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":6,"value":"import {unzipSync} from \"npm:fflate\";","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":7,"value":"const files = unzipSync(new Uint8Array(zbuf));\nconst csvText = new TextDecoder().decode(Object.values(files)[0]);","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":8,"value":"const rows = d3.csvParse(csvText, (d) => ({\n ride_id: d.ride_id,\n rideable_type: d.rideable_type,\n started_at: new Date(d.started_at.replace(\" \", \"T\") + \"Z\"),\n ended_at: new Date(d.ended_at.replace(\" \", \"T\") + \"Z\"),\n start_station_name: d.start_station_name,\n start_station_id: d.start_station_id,\n end_station_name: d.end_station_name,\n end_station_id: d.end_station_id,\n start_lat: +d.start_lat, start_lng: +d.start_lng,\n end_lat: +d.end_lat, end_lng: +d.end_lng,\n member_casual: d.member_casual\n}));\nconst bikedb = await DuckDBClient.of({trips: rows});\ndisplay(rows.length);","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":22,"value":"const dayNames = [\"Sunday\", \"Monday\", \"Tuesday\", \"Wednesday\", \"Thursday\", \"Friday\", \"Saturday\"];\nconst dayOrder = dayNames.slice(1).concat(dayNames[0]);\n// Timestamps were parsed as UTC but hold local wall-clock time, so use UTC getters.\nconst datesPerDay = d3.rollup(rows, (v) => new Set(v.map((d) => d.started_at.toISOString().slice(0, 10))).size, (d) => dayNames[d.started_at.getUTCDay()]);\nconst binned = d3.rollup(\n rows,\n (v) => v.length,\n (d) => dayNames[d.started_at.getUTCDay()],\n (d) => Math.floor((d.started_at.getUTCHours() * 60 + d.started_at.getUTCMinutes()) / 15)\n);\nconst horizonData = dayOrder.flatMap((day) =>\n d3.range(96).map((b) => ({\n day,\n hour: b / 4,\n trips: (binned.get(day)?.get(b) ?? 0) / datesPerDay.get(day)\n }))\n);\ndisplay(Inputs.table(horizonData));","pinned":true,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":23,"value":"$4d","pinned":false,"hidden":false,"mode":"js","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W4e","stdlib":"2"}} 24:null