diff --git a/src/repositories/shuttle/eta/RedisSelfUpdatingETARepository.ts b/src/repositories/shuttle/eta/RedisSelfUpdatingETARepository.ts
index 971c21e..322c11a 100644
--- a/src/repositories/shuttle/eta/RedisSelfUpdatingETARepository.ts
+++ b/src/repositories/shuttle/eta/RedisSelfUpdatingETARepository.ts
@@ -19,14 +19,52 @@ export class RedisSelfUpdatingETARepository extends BaseRedisETARepository imple
     private referenceTime: Date | null = null,
   ) {
     super(redisClient);
+
+    this.setReferenceTime = this.setReferenceTime.bind(this);
+    this.getAverageTravelTimeSeconds = this.getAverageTravelTimeSeconds.bind(this);
+    this.startListeningForUpdates = this.startListeningForUpdates.bind(this);
+    this.handleShuttleWillArriveAtStop = this.handleShuttleWillArriveAtStop.bind(this);
+    this.handleShuttleUpdate = this.handleShuttleUpdate.bind(this);
+  }
+
+  private createHistoricalEtaTimeSeriesKey = (routeId: string, fromStopId: string, toStopId: string) => {
+    return `shuttle:eta:historical:${routeId}:${fromStopId}:${toStopId}`;
   }
 
   setReferenceTime(referenceTime: Date) {
     this.referenceTime = referenceTime;
   }
 
-  getAverageTravelTimeSeconds(identifier: ShuttleTravelTimeDataIdentifier, dateFilter: ShuttleTravelTimeDateFilterArguments): Promise<number | undefined> {
-    throw new Error("Method not implemented.");
+  public async getAverageTravelTimeSeconds(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    { from, to }: ShuttleTravelTimeDateFilterArguments
+  ): Promise<number | undefined> {
+    const timeSeriesKey = this.createHistoricalEtaTimeSeriesKey(routeId, fromStopId, toStopId);
+    const fromTimestamp = from.getTime();
+    const toTimestamp = to.getTime();
+    const intervalMs = toTimestamp - fromTimestamp + 1;
+
+    try {
+      const aggregationResult = await this.redisClient.sendCommand([
+        'TS.RANGE',
+        timeSeriesKey,
+        fromTimestamp.toString(),
+        toTimestamp.toString(),
+        'AGGREGATION',
+        'AVG',
+        intervalMs.toString()
+      ]) as [string, string][];
+
+      if (aggregationResult && aggregationResult.length > 0) {
+        const [, averageValue] = aggregationResult[0];
+        return parseFloat(averageValue);
+      }
+
+      return;
+    } catch (error) {
+      console.warn(`Failed to get average travel time: ${error instanceof Error ? error.message : String(error)}`);
+      return;
+    }
   }
 
   startListeningForUpdates() {