diff --git a/common/api/hooks/slowzones.ts b/common/api/hooks/slowzones.ts
index ed3e78679..7640784d1 100644
--- a/common/api/hooks/slowzones.ts
+++ b/common/api/hooks/slowzones.ts
@@ -1,6 +1,7 @@
 import { useQuery } from '@tanstack/react-query';
 import { fetchAllSlow, fetchDelayTotals, fetchSpeedRestrictions } from '../slowzones';
 import { ONE_HOUR } from '../../constants/time';
+import type { FetchSpeedRestrictionsOptions } from '../../types/api';
 
 export const useSlowzoneAllData = () => {
   return useQuery(['allSlow'], fetchAllSlow, { staleTime: ONE_HOUR });
@@ -10,6 +11,9 @@ export const useSlowzoneDelayTotalData = () => {
   return useQuery(['delayTotals'], fetchDelayTotals, { staleTime: ONE_HOUR });
 };
 
-export const useSpeedRestrictionData = () => {
-  return useQuery(['speedRestrictions'], fetchSpeedRestrictions);
+export const useSpeedRestrictionData = (options: FetchSpeedRestrictionsOptions) => {
+  return useQuery(['speedRestrictions', options], () => fetchSpeedRestrictions(options), {
+    enabled: true,
+    staleTime: ONE_HOUR,
+  });
 };
diff --git a/common/api/slowzones.ts b/common/api/slowzones.ts
index b463ff2bb..670bf7688 100644
--- a/common/api/slowzones.ts
+++ b/common/api/slowzones.ts
@@ -3,6 +3,8 @@ import type {
   SlowZoneResponse,
   SpeedRestriction,
 } from '../../common/types/dataPoints';
+import type { FetchSpeedRestrictionsOptions } from '../types/api';
+import { getGtfsRailLineId } from '../utils/lines';
 
 export const fetchDelayTotals = (): Promise<DayDelayTotals[]> => {
   const url = new URL(`/static/slowzones/delay_totals.json`, window.location.origin);
@@ -14,10 +16,20 @@ export const fetchAllSlow = (): Promise<SlowZoneResponse[]> => {
   return fetch(all_slow_url.toString()).then((resp) => resp.json());
 };
 
-export const fetchSpeedRestrictions = (): Promise<SpeedRestriction[]> => {
-  const speed_restrictions_url = new URL(
-    `/static/slowzones/speed_restrictions.json`,
+export const fetchSpeedRestrictions = async (
+  options: FetchSpeedRestrictionsOptions
+): Promise<SpeedRestriction[]> => {
+  const { lineId, date: requestedDate } = options;
+  const params = new URLSearchParams({ line_id: getGtfsRailLineId(lineId), date: requestedDate });
+  const speedRestrictionsUrl = new URL(
+    '/api/speed_restrictions?' + params.toString(),
     window.location.origin
   );
-  return fetch(speed_restrictions_url.toString()).then((resp) => resp.json());
+  const today = new Date();
+  const response = await fetch(speedRestrictionsUrl.toString());
+  const { available, date: resolvedDate, zones } = await response.json();
+  if (available) {
+    return zones.map((zone) => ({ ...zone, currentAsOf: resolvedDate, validAsOf: today }));
+  }
+  return [];
 };
diff --git a/common/types/api.ts b/common/types/api.ts
index 91e16402e..c7a83d32b 100644
--- a/common/types/api.ts
+++ b/common/types/api.ts
@@ -83,3 +83,14 @@ export enum FetchRidershipParams {
   startDate = 'start_date',
   endDate = 'end_date',
 }
+
+export type FetchSpeedRestrictionsOptions = {
+  lineId: Line;
+  date: string;
+};
+
+export type FetchSpeedRestrictionsResponse = {
+  available: boolean;
+  date: string;
+  zones: Record<string, any>[];
+};
diff --git a/common/types/dataPoints.ts b/common/types/dataPoints.ts
index fc7467159..f4507f2bb 100644
--- a/common/types/dataPoints.ts
+++ b/common/types/dataPoints.ts
@@ -100,13 +100,14 @@ export type SpeedRestriction = {
   line: Exclude<LineShort, 'Bus'>;
   description: string;
   reason: string;
-  status: string;
   fromStopId: null | string;
   toStopId: null | string;
   reported: string;
-  cleared: string;
   speedMph: number;
   trackFeet: number;
+  currentAsOf: Date;
+  lineId: Line;
+  validAsOf: Date;
 };
 
 export type DayKind = 'weekday' | 'saturday' | 'sunday';
diff --git a/common/types/lines.ts b/common/types/lines.ts
index bb577316d..a3a033f9e 100644
--- a/common/types/lines.ts
+++ b/common/types/lines.ts
@@ -33,6 +33,9 @@ export const RIDERSHIP_KEYS = {
   'line-green': 'line-Green',
 };
 
+export const GTFS_COLOR_LINE_IDS = ['line-Red', 'line-Orange', 'line-Blue', 'line-Green'] as const;
+export type GtfsColorLineId = (typeof GTFS_COLOR_LINE_IDS)[number];
+
 export const HEAVY_RAIL_LINES: Line[] = ['line-red', 'line-orange', 'line-blue'];
 export const LANDING_RAIL_LINES: Line[] = ['line-red', 'line-orange', 'line-blue', 'line-green'];
 
diff --git a/common/utils/date.ts b/common/utils/date.ts
index 67bf0ff11..6622eb1eb 100644
--- a/common/utils/date.ts
+++ b/common/utils/date.ts
@@ -6,7 +6,9 @@ export const prettyDate = (dateString: string, withDow: boolean) => {
     weekday: withDow ? 'long' : undefined,
   };
 
-  const fullDate = dateString.includes('T') ? dateString : `${dateString}T00:00:00`;
+  const fullDate = dateString.includes('T')
+    ? dateString
+    : /* Offset so that it's always past midnight in Boston */ `${dateString}T07:00:00`;
 
   return new Date(fullDate).toLocaleDateString(
     undefined, // user locale/language
diff --git a/common/utils/lines.ts b/common/utils/lines.ts
index bc7feff92..553f797b6 100644
--- a/common/utils/lines.ts
+++ b/common/utils/lines.ts
@@ -1,7 +1,13 @@
-import { LINE_OBJECTS } from '../constants/lines';
-import type { LineShort } from '../types/lines';
+import type { GtfsColorLineId, Line, LineShort } from '../types/lines';
+import { RAIL_LINES } from '../types/lines';
 
-export const shortToLine = (name: LineShort): Exclude<LineShort, 'Bus'> => {
-  const found = Object.entries(LINE_OBJECTS).find(([, line]) => line.short === name);
-  return found?.[0] as Exclude<LineShort, 'Bus'>;
+export const getGtfsRailLineId = (name: Line | LineShort): GtfsColorLineId => {
+  const normalizedColorPart = (
+    name.includes('line-') ? name.replace('line-', '') : name
+  ).toLowerCase();
+  if (!RAIL_LINES.includes(normalizedColorPart)) {
+    throw new Error('Not a valid rail line ID');
+  }
+  const capped = normalizedColorPart.slice(0, 1).toUpperCase() + normalizedColorPart.slice(1);
+  return `line-${capped}` as GtfsColorLineId;
 };
diff --git a/modules/dashboard/Today.tsx b/modules/dashboard/Today.tsx
index e04efd674..843629b9a 100644
--- a/modules/dashboard/Today.tsx
+++ b/modules/dashboard/Today.tsx
@@ -5,6 +5,7 @@ import { SlowZonesMap } from '../slowzones/map';
 import { WidgetDiv } from '../../common/components/widgets/WidgetDiv';
 import { useSlowzoneAllData, useSpeedRestrictionData } from '../../common/api/hooks/slowzones';
 import { PageWrapper } from '../../common/layouts/PageWrapper';
+import type { Line } from '../../common/types/lines';
 import { WidgetTitle } from './WidgetTitle';
 
 interface TodayProps {
@@ -13,7 +14,10 @@ interface TodayProps {
 
 export const Today: React.FC<TodayProps> = ({ lineShort }) => {
   const allSlow = useSlowzoneAllData();
-  const speedRestrictions = useSpeedRestrictionData();
+  const speedRestrictions = useSpeedRestrictionData({
+    lineId: `line-${lineShort.toLowerCase()}` as Line,
+    date: new Date().toISOString().split('T')[0],
+  });
   const canShowSlowZonesMap = lineShort !== 'Green';
 
   return (
diff --git a/modules/slowzones/SlowZonesDetails.tsx b/modules/slowzones/SlowZonesDetails.tsx
index 6066593fd..f3706e9a3 100644
--- a/modules/slowzones/SlowZonesDetails.tsx
+++ b/modules/slowzones/SlowZonesDetails.tsx
@@ -25,10 +25,8 @@ import { SlowZonesWidgetTitle } from './SlowZonesWidgetTitle';
 dayjs.extend(utc);
 
 export function SlowZonesDetails() {
-  const delayTotals = useSlowzoneDelayTotalData();
   const [direction, setDirection] = useState<Direction>('northbound');
-  const allSlow = useSlowzoneAllData();
-  const speedRestrictions = useSpeedRestrictionData();
+
   const {
     lineShort,
     linePath,
@@ -36,6 +34,10 @@ export function SlowZonesDetails() {
     query: { startDate, endDate },
   } = useDelimitatedRoute();
 
+  const delayTotals = useSlowzoneDelayTotalData();
+  const allSlow = useSlowzoneAllData();
+  const speedRestrictions = useSpeedRestrictionData({ lineId: line!, date: endDate! });
+
   const startDateUTC = startDate ? dayjs.utc(startDate).startOf('day') : undefined;
   const endDateUTC = endDate ? dayjs.utc(endDate).startOf('day') : undefined;
   const totalSlowTimeReady =
diff --git a/modules/slowzones/map/SlowZonesTooltip.tsx b/modules/slowzones/map/SlowZonesTooltip.tsx
index 9c35c029a..5783c14a4 100644
--- a/modules/slowzones/map/SlowZonesTooltip.tsx
+++ b/modules/slowzones/map/SlowZonesTooltip.tsx
@@ -67,7 +67,7 @@ export const SlowZonesTooltip: React.FC<SlowZonesTooltipProps> = (props) => {
       const totalFeet = speedRestrictions.reduce((sum, sr) => sum + sr.trackFeet, 0);
       const [oldest] = speedRestrictions
         .filter((sr) => sr.reported)
-        .map((sr) => new Date(sr.reported).toISOString())
+        .map((sr) => sr.reported)
         .sort();
       const oldestString = prettyDate(oldest, false);
       return (
diff --git a/modules/slowzones/map/segment.ts b/modules/slowzones/map/segment.ts
index 2f2e9ddad..66d1bdfe6 100644
--- a/modules/slowzones/map/segment.ts
+++ b/modules/slowzones/map/segment.ts
@@ -142,8 +142,8 @@ export const segmentSlowZones = (options: SegmentSlowZonesOptions): Segmentation
       speedRestrictions,
       lineName,
       effectiveDate,
-      (rs) => new Date(rs.cleared ?? '4000'),
-      (rs) => rs.line
+      (rs) => rs.validAsOf,
+      (rs) => rs.lineId.replace('line-', '') as LineShort
     ),
     (rs) => getStationById(rs.fromStopId!),
     (rs) => getStationById(rs.toStopId!)
diff --git a/server/app.py b/server/app.py
index 58486c7c3..44aee1a24 100644
--- a/server/app.py
+++ b/server/app.py
@@ -11,6 +11,7 @@
     secrets,
     mbta_v3,
     speed,
+    speed_restrictions,
     service_levels,
     ridership,
 )
@@ -47,7 +48,9 @@ def healthcheck():
         "API Key Present": (lambda: len(secrets.MBTA_V2_API_KEY) > 0),
         "S3 Headway Fetching": (
             lambda: "2020-11-07 10:33:40"
-            in json.dumps(data_funcs.headways(date(year=2020, month=11, day=7), ["70061"]))
+            in json.dumps(
+                data_funcs.headways(date(year=2020, month=11, day=7), ["70061"])
+            )
         ),
         "Performance API Check": (
             lambda: MbtaPerformanceAPI.get_api_data(
@@ -109,7 +112,9 @@ def traveltime_route(user_date):
 @app.route("/api/alerts/{user_date}", cors=cors_config)
 def alerts_route(user_date):
     date = parse_user_date(user_date)
-    return json.dumps(data_funcs.alerts(date, mutlidict_to_dict(app.current_request.query_params)))
+    return json.dumps(
+        data_funcs.alerts(date, mutlidict_to_dict(app.current_request.query_params))
+    )
 
 
 @app.route("/api/aggregate/traveltimes", cors=cors_config)
@@ -158,7 +163,11 @@ def dwells_aggregate_route():
 def get_git_id():
     # Only do this on localhost
     if TM_FRONTEND_HOST == "localhost":
-        git_id = str(subprocess.check_output(["git", "describe", "--always", "--dirty", "--abbrev=10"]))[2:-3]
+        git_id = str(
+            subprocess.check_output(
+                ["git", "describe", "--always", "--dirty", "--abbrev=10"]
+            )
+        )[2:-3]
         return json.dumps({"git_id": git_id})
     else:
         raise ConflictError("Cannot get git id from serverless host")
@@ -204,3 +213,15 @@ def get_ridership():
         line_id=line_id,
     )
     return json.dumps(response)
+
+
+@app.route("/api/speed_restrictions", cors=cors_config)
+def get_speed_restrictions():
+    query = app.current_request.query_params
+    on_date = query["date"]
+    line_id = query["line_id"]
+    response = speed_restrictions.query_speed_restrictions(
+        line_id=line_id,
+        on_date=on_date,
+    )
+    return json.dumps(response)
diff --git a/server/chalicelib/speed_restrictions.py b/server/chalicelib/speed_restrictions.py
new file mode 100644
index 000000000..4a7ac5be8
--- /dev/null
+++ b/server/chalicelib/speed_restrictions.py
@@ -0,0 +1,36 @@
+from boto3.dynamodb.conditions import Key
+from dynamodb_json import json_util as ddb_json
+
+from .dynamo import dynamodb
+
+SpeedRestrictions = dynamodb.Table("SpeedRestrictions")
+
+
+def get_boundary_date(line_id: str, first: bool):
+    response = SpeedRestrictions.query(
+        KeyConditionExpression=Key("lineId").eq(line_id),
+        ScanIndexForward=first,
+        Limit=1,
+    )
+    loaded = ddb_json.loads(response["Items"])
+    return loaded[0]["date"]
+
+
+def query_speed_restrictions(line_id: str, on_date: str):
+    first_sr_date = get_boundary_date(line_id=line_id, first=True)
+    latest_sr_date = get_boundary_date(line_id=line_id, first=False)
+    if on_date < first_sr_date:
+        return {"available": False}
+    if on_date > latest_sr_date:
+        on_date = latest_sr_date
+    line_condition = Key("lineId").eq(line_id)
+    date_condition = Key("date").eq(on_date)
+    condition = line_condition & date_condition
+    response = SpeedRestrictions.query(KeyConditionExpression=condition, Limit=1)
+    response_item = ddb_json.loads(response["Items"])[0]
+    zones = response_item.get("zones", {}).get("zones", {})
+    return {
+        "available": True,
+        "date": on_date,
+        "zones": zones,
+    }