The Arcade Physics Body has a new property maxSpeed which limits the vector length of the Body velocity. You can set it via the method setMaxSpeed and it is applied in the World.computeVelocity method

Author: photonstorm

CHANGELOG.md

@@ -270,6 +270,7 @@ one set of bindings ever created, which makes things a lot cleaner.
 * `Vector3.BACK` is a new constant that can be used in Vector comparison operations (thanks @Aedalus)
 * `Vector3.ONE` is a new constant that can be used in Vector comparison operations (thanks @Aedalus)
 * Geometery Mask has a new property called `invertAlpha` in WebGL, which works in the same way as the flag on the Bitmap Mask and allows you to invert the function of the stencil buffer, i.e. non-drawn shapes become invisible, and drawn shapes visible (thanks @tfelix)
+* The Arcade Physics Body has a new property `maxSpeed` which limits the vector length of the Body velocity. You can set it via the method `setMaxSpeed` and it is applied in the `World.computeVelocity` method (thanks @Edwin222 @rexrainbow)
 
 ### Updates
 

src/physics/arcade/Body.js

@@ -438,6 +438,19 @@ var Body = new Class({
          */
         this.maxVelocity = new Vector2(10000, 10000);
 
+	    /**
+         * The maximum speed this Body is allowed to reach.
+         * 
+         * If not negative it limits the scalar value of speed.
+         * 
+         * Any negative value means no maximum is being applied.
+         * 
+         * @name Phaser.Physics.Arcade.Body#maxSpeed
+         * @type {number}
+         * @since 3.16.0 
+         */
+        this.maxSpeed = -1;
+
         /**
          * If this Body is `immovable` and in motion, `friction` is the proportion of this Body's motion received by the riding Body on each axis, relative to 1.
          * The default value (1, 0) moves the riding Body horizontally in equal proportion to this Body and vertically not at all.
@@ -1554,6 +1567,23 @@ var Body = new Class({
         return this;
     },
 
+    /**
+     * Sets the maximum speed the Body can move.
+     *
+     * @method Phaser.Physics.Arcade.Body#setMaxSpeed
+     * @since 3.16.0
+     *
+     * @param {number} value - The maximum speed value, in pixels per second. Set to a negative value to disable.
+     *
+     * @return {Phaser.Physics.Arcade.Body} This Body object.
+     */
+    setMaxSpeed: function (value)
+    {
+        this.maxSpeed = value;
+
+        return this;
+    },
+
     /**
      * Sets the Body's bounce.
      *

src/physics/arcade/World.js

@@ -1287,6 +1287,7 @@ var World = new Class({
         var maxY = body.maxVelocity.y;
 
         var speed = body.speed;
+        var maxSpeed = body.maxSpeed;
         var allowDrag = body.allowDrag;
         var useDamping = body.useDamping;
 
@@ -1372,6 +1373,11 @@ var World = new Class({
         velocityY = Clamp(velocityY, -maxY, maxY);
 
         body.velocity.set(velocityX, velocityY);
+
+        if (maxSpeed > -1 && body.velocity.length() > maxSpeed)
+        {
+            body.velocity.normalize().scale(maxSpeed);
+        }
     },
 
     /**