diff --git a/src/front/index.js b/src/front/index.js
index dd1cd03..2ca7618 100644
--- a/src/front/index.js
+++ b/src/front/index.js
@@ -7,8 +7,6 @@ const map = require("./map/index.js");
 
 // Run courses simulation
 const coursesSimulation = simulation.start();
-global.courses = coursesSimulation.courses;
-
 const informations = document.querySelector("#informations");
 let courseId = null;
 
@@ -16,7 +14,7 @@ const displayTime = date => [
     date.getHours(),
     date.getMinutes(),
     date.getSeconds()
-].map(number => number.toString().padStart(2, '0')).join(':');
+].map(number => number.toString().padStart(2, "0")).join(":");
 
 setInterval(() => {
     let html = `
@@ -38,7 +36,7 @@ setInterval(() => {
                 <td>${stopToHTML(stopId)}</td>
                 <td>${displayTime(new Date(time))}</td>
             </tr>
-        `).join('\n');
+        `).join("\n");
 
         html += `
             <dl>
@@ -52,12 +50,12 @@ setInterval(() => {
                 <dd>${stopToHTML(course.finalStop)}</dd>
 
                 <dt>État</dt>
-                <dd>${course.state === 'moving'
-                        ? `Entre ${stopToHTML(course.departureStop)}
-                           et ${stopToHTML(course.arrivalStop)}`
-                        : `À l’arrêt ${stopToHTML(course.currentStop)}`}</dd>
+                <dd>${course.state === "moving"
+        ? `Entre ${stopToHTML(course.departureStop)}
+            et ${stopToHTML(course.arrivalStop)}`
+        : `À l’arrêt ${stopToHTML(course.currentStop)}`}</dd>
 
-                ${course.state === 'moving' ? `
+                ${course.state === "moving" ? `
                     <dt>Arrivée dans</dt>
                     <dd>${timeToHTML(course.arrivalTime)} s</dd>
 
diff --git a/src/tam/network.js b/src/tam/network.js
index 62bbd57..cc679ed 100644
--- a/src/tam/network.js
+++ b/src/tam/network.js
@@ -89,7 +89,7 @@ a “ref” tag`);
                         ], {
                             name: stop.tags.name,
                             routes: [[lineRef, routeRef]],
-                            successors: [],
+                            successors: []
                         });
                     } else {
                         stops[stop.tags.ref].properties.routes.push([
diff --git a/src/tam/realtime.js b/src/tam/realtime.js
index 4bf2e07..38efc77 100644
--- a/src/tam/realtime.js
+++ b/src/tam/realtime.js
@@ -53,10 +53,16 @@ const fetch = async() => {
                     id,
                     line,
                     finalStop,
-                    nextPassings: [[stopId, arrivalTime]]
+
+                    // Initially accumulate passings in an object
+                    // to prevent duplicates
+                    nextPassings: { [stopId]: arrivalTime }
                 };
-            } else {
-                courses[id].nextPassings.push([stopId, arrivalTime]);
+            } else if (!(stopId in courses[id].nextPassings) ||
+                        courses[id].nextPassings[stopId] < arrivalTime) {
+                // Only consider passings with an increased passing time
+                // or for stops not seen before
+                courses[id].nextPassings[stopId] = arrivalTime;
             }
         }
 
@@ -67,7 +73,7 @@ const fetch = async() => {
             if (!(course.line in network.lines)) {
                 delete courses[courseId];
             } else {
-                for (const [stopId,] of course.nextPassings) {
+                for (const stopId of Object.keys(course.nextPassings)) {
                     if (!(stopId in network.stops)) {
                         delete courses[courseId];
                         break;
@@ -78,8 +84,10 @@ const fetch = async() => {
 
         // Order next passings by increasing passing time
         for (const courseId of Object.keys(courses)) {
-            courses[courseId].nextPassings.sort(
-                ([, time1], [, time2]) => time1 - time2
+            courses[courseId].nextPassings = (
+                Object.entries(courses[courseId].nextPassings).sort(
+                    ([, time1], [, time2]) => time1 - time2
+                )
             );
         }
 
diff --git a/src/tam/simulation.js b/src/tam/simulation.js
index 05cfbf4..a6701bb 100644
--- a/src/tam/simulation.js
+++ b/src/tam/simulation.js
@@ -5,8 +5,6 @@ const network = require("./network.json");
 
 const server = "http://localhost:4321";
 
-const stops = Object.keys(network.stops);
-
 const findRoute = (from, to) => {
     const queue = [[from, []]];
 
@@ -84,7 +82,7 @@ class Course {
             }
         } else if (this.state === "moving") {
             const index = this.nextPassings.findIndex(
-                ([stop, ]) => stop === this.arrivalStop
+                ([stop]) => stop === this.arrivalStop
             );
 
             if (index === -1 || this.nextPassings[index][1] <= now) {
@@ -99,7 +97,7 @@ class Course {
             // (this.state === 'stopped')
             // Try moving to the next stop
             const index = this.nextPassings.findIndex(
-                ([stop, ]) => stop === this.currentStop
+                ([stop]) => stop === this.currentStop
             );
 
             if (index !== -1) {
@@ -123,11 +121,11 @@ class Course {
                 let found = false;
 
                 for (
-                    let index = 0;
-                    index < this.nextPassings.length;
-                    ++index
+                    let nextIndex = 0;
+                    nextIndex < this.nextPassings.length;
+                    ++nextIndex
                 ) {
-                    const [stop, arrivalTime] = this.nextPassings[index];
+                    const [stop, arrivalTime] = this.nextPassings[nextIndex];
 
                     if (arrivalTime > now) {
                         const route = findRoute(this.currentStop, stop);
@@ -173,7 +171,8 @@ class Course {
             const segment = this.currentSegment;
             const distance = segment.properties.length - this.traveledDistance;
             const duration = this.arrivalTime - Date.now();
-            this.speed = this.computeSpeed(distance, duration);
+
+            this.speed = Course.computeSpeed(distance, duration);
         }
 
         return true;
@@ -247,7 +246,7 @@ ${this.currentStop} to stop ${stop}. Teleporting to ${stop}`);
         const distance = network.segments[segmentId].properties.length;
         const duration = arrivalTime - Date.now();
 
-        if (this.computeSpeed(distance, duration) === 0) {
+        if (Course.computeSpeed(distance, duration) === 0) {
             // Speed would be too low, better wait for some time
             return;
         }
@@ -260,7 +259,7 @@ ${this.currentStop} to stop ${stop}. Teleporting to ${stop}`);
         this.speed = 0;
     }
 
-    computeSpeed(distance, duration) {
+    static computeSpeed(distance, duration) {
         if (duration <= 0) {
             // Late: go to maximum speed
             return 50 / 3600;