diff --git a/system/Router/RouteCollection.php b/system/Router/RouteCollection.php
index f535d392817c..030edf8f9ca1 100644
--- a/system/Router/RouteCollection.php
+++ b/system/Router/RouteCollection.php
@@ -116,12 +116,20 @@ class RouteCollection implements RouteCollectionInterface
      *
      * [
      *     verb => [
-     *         routeName => [
-     *             'route' => [
-     *                 routeKey(regex) => handler,
-     *             ],
+     *         routeKey(regex) => [
+     *             'name'    => routeName
+     *             'handler' => handler,
+     *             'from'    => from,
+     *         ],
+     *     ],
+     *     // redirect route
+     *     '*' => [
+     *          routeKey(regex)(from) => [
+     *             'name'     => routeName
+     *             'handler'  => [routeKey(regex)(to) => handler],
+     *             'from'     => from,
      *             'redirect' => statusCode,
-     *         ]
+     *         ],
      *     ],
      * ]
      */
@@ -138,6 +146,30 @@ class RouteCollection implements RouteCollectionInterface
         'cli'     => [],
     ];
 
+    /**
+     * Array of routes names
+     *
+     * @var array
+     *
+     * [
+     *     verb => [
+     *         routeName => routeKey(regex)
+     *     ],
+     * ]
+     */
+    protected $routesNames = [
+        '*'       => [],
+        'options' => [],
+        'get'     => [],
+        'head'    => [],
+        'post'    => [],
+        'put'     => [],
+        'delete'  => [],
+        'trace'   => [],
+        'connect' => [],
+        'cli'     => [],
+    ];
+
     /**
      * Array of routes options
      *
@@ -537,9 +569,8 @@ public function getRoutes(?string $verb = null): array
             // before any of the generic, "add" routes.
             $collection = $this->routes[$verb] + ($this->routes['*'] ?? []);
 
-            foreach ($collection as $r) {
-                $key          = key($r['route']);
-                $routes[$key] = $r['route'][$key];
+            foreach ($collection as $routeKey => $r) {
+                $routes[$routeKey] = $r['handler'];
             }
         }
 
@@ -638,27 +669,41 @@ public function add(string $from, $to, ?array $options = null): RouteCollectionI
     public function addRedirect(string $from, string $to, int $status = 302)
     {
         // Use the named route's pattern if this is a named route.
-        if (array_key_exists($to, $this->routes['*'])) {
-            $to = $this->routes['*'][$to]['route'];
-        } elseif (array_key_exists($to, $this->routes['get'])) {
-            $to = $this->routes['get'][$to]['route'];
+        if (array_key_exists($to, $this->routesNames['*'])) {
+            $routeName  = $to;
+            $routeKey   = $this->routesNames['*'][$routeName];
+            $redirectTo = [$routeKey => $this->routes['*'][$routeKey]['handler']];
+        } elseif (array_key_exists($to, $this->routesNames['get'])) {
+            $routeName  = $to;
+            $routeKey   = $this->routesNames['get'][$routeName];
+            $redirectTo = [$routeKey => $this->routes['get'][$routeKey]['handler']];
+        } else {
+            // The named route is not found.
+            $redirectTo = $to;
         }
 
-        $this->create('*', $from, $to, ['redirect' => $status]);
+        $this->create('*', $from, $redirectTo, ['redirect' => $status]);
 
         return $this;
     }
 
     /**
      * Determines if the route is a redirecting route.
+     *
+     * @param string $routeKey routeKey or route name
      */
-    public function isRedirect(string $from): bool
+    public function isRedirect(string $routeKey): bool
     {
-        foreach ($this->routes['*'] as $name => $route) {
-            // Named route?
-            if ($name === $from || key($route['route']) === $from) {
-                return isset($route['redirect']) && is_numeric($route['redirect']);
-            }
+        if (isset($this->routes['*'][$routeKey]['redirect'])) {
+            return true;
+        }
+
+        // This logic is not used. Should be deprecated?
+        $routeName = $this->routes['*'][$routeKey]['name'] ?? null;
+        if ($routeName === $routeKey) {
+            $routeKey = $this->routesNames['*'][$routeName];
+
+            return isset($this->routes['*'][$routeKey]['redirect']);
         }
 
         return false;
@@ -666,14 +711,21 @@ public function isRedirect(string $from): bool
 
     /**
      * Grabs the HTTP status code from a redirecting Route.
+     *
+     * @param string $routeKey routeKey or route name
      */
-    public function getRedirectCode(string $from): int
+    public function getRedirectCode(string $routeKey): int
     {
-        foreach ($this->routes['*'] as $name => $route) {
-            // Named route?
-            if ($name === $from || key($route['route']) === $from) {
-                return $route['redirect'] ?? 0;
-            }
+        if (isset($this->routes['*'][$routeKey]['redirect'])) {
+            return $this->routes['*'][$routeKey]['redirect'];
+        }
+
+        // This logic is not used. Should be deprecated?
+        $routeName = $this->routes['*'][$routeKey]['name'] ?? null;
+        if ($routeName === $routeKey) {
+            $routeKey = $this->routesNames['*'][$routeName];
+
+            return $this->routes['*'][$routeKey]['redirect'];
         }
 
         return 0;
@@ -1088,9 +1140,11 @@ public function environment(string $env, Closure $callback): RouteCollectionInte
     public function reverseRoute(string $search, ...$params)
     {
         // Named routes get higher priority.
-        foreach ($this->routes as $collection) {
+        foreach ($this->routesNames as $collection) {
             if (array_key_exists($search, $collection)) {
-                return $this->buildReverseRoute(key($collection[$search]['route']), $params);
+                $routeKey = $collection[$search];
+
+                return $this->buildReverseRoute($routeKey, $params);
             }
         }
 
@@ -1106,9 +1160,8 @@ public function reverseRoute(string $search, ...$params)
         // If it's not a named route, then loop over
         // all routes to find a match.
         foreach ($this->routes as $collection) {
-            foreach ($collection as $route) {
-                $from = key($route['route']);
-                $to   = $route['route'][$from];
+            foreach ($collection as $routeKey => $route) {
+                $to = $route['handler'];
 
                 // ignore closures
                 if (! is_string($to)) {
@@ -1132,7 +1185,7 @@ public function reverseRoute(string $search, ...$params)
                     continue;
                 }
 
-                return $this->buildReverseRoute($from, $params);
+                return $this->buildReverseRoute($routeKey, $params);
             }
         }
 
@@ -1247,21 +1300,21 @@ protected function fillRouteParams(string $from, ?array $params = null): string
      * @param array $params One or more parameters to be passed to the route.
      *                      The last parameter allows you to set the locale.
      */
-    protected function buildReverseRoute(string $from, array $params): string
+    protected function buildReverseRoute(string $routeKey, array $params): string
     {
         $locale = null;
 
         // Find all of our back-references in the original route
-        preg_match_all('/\(([^)]+)\)/', $from, $matches);
+        preg_match_all('/\(([^)]+)\)/', $routeKey, $matches);
 
         if (empty($matches[0])) {
-            if (strpos($from, '{locale}') !== false) {
+            if (strpos($routeKey, '{locale}') !== false) {
                 $locale = $params[0] ?? null;
             }
 
-            $from = $this->replaceLocale($from, $locale);
+            $routeKey = $this->replaceLocale($routeKey, $locale);
 
-            return '/' . ltrim($from, '/');
+            return '/' . ltrim($routeKey, '/');
         }
 
         // Locale is passed?
@@ -1279,13 +1332,13 @@ protected function buildReverseRoute(string $from, array $params): string
 
             // Ensure that the param we're inserting matches
             // the expected param type.
-            $pos  = strpos($from, $pattern);
-            $from = substr_replace($from, $params[$index], $pos, strlen($pattern));
+            $pos      = strpos($routeKey, $pattern);
+            $routeKey = substr_replace($routeKey, $params[$index], $pos, strlen($pattern));
         }
 
-        $from = $this->replaceLocale($from, $locale);
+        $routeKey = $this->replaceLocale($routeKey, $locale);
 
-        return '/' . ltrim($from, '/');
+        return '/' . ltrim($routeKey, '/');
     }
 
     /**
@@ -1333,7 +1386,7 @@ protected function create(string $verb, string $from, $to, ?array $options = nul
         }
 
         // When redirecting to named route, $to is an array like `['zombies' => '\Zombies::index']`.
-        if (is_array($to) && count($to) === 2) {
+        if (is_array($to) && isset($to[0])) {
             $to = $this->processArrayCallableSyntax($from, $to);
         }
 
@@ -1385,10 +1438,11 @@ protected function create(string $verb, string $from, $to, ?array $options = nul
             }
         }
 
+        $routeKey = $from;
         // Replace our regex pattern placeholders with the actual thing
         // so that the Router doesn't need to know about any of this.
         foreach ($this->placeholders as $tag => $pattern) {
-            $from = str_ireplace(':' . $tag, $pattern, $from);
+            $routeKey = str_ireplace(':' . $tag, $pattern, $routeKey);
         }
 
         // If is redirect, No processing
@@ -1403,7 +1457,7 @@ protected function create(string $verb, string $from, $to, ?array $options = nul
             $to = '\\' . ltrim($to, '\\');
         }
 
-        $name = $options['as'] ?? $from;
+        $name = $options['as'] ?? $routeKey;
 
         helper('array');
 
@@ -1412,20 +1466,22 @@ protected function create(string $verb, string $from, $to, ?array $options = nul
         // routes should always be the "source of truth".
         // this works only because discovered routes are added just prior
         // to attempting to route the request.
-        $fromExists = dot_array_search('*.route.' . $from, $this->routes[$verb] ?? []) !== null;
-        if ((isset($this->routes[$verb][$name]) || $fromExists) && ! $overwrite) {
+        $routeKeyExists = isset($this->routes[$verb][$routeKey]);
+        if ((isset($this->routesNames[$verb][$name]) || $routeKeyExists) && ! $overwrite) {
             return;
         }
 
-        $this->routes[$verb][$name] = [
-            'route' => [$from => $to],
+        $this->routes[$verb][$routeKey] = [
+            'name'    => $name,
+            'handler' => $to,
+            'from'    => $from,
         ];
-
-        $this->routesOptions[$verb][$from] = $options;
+        $this->routesOptions[$verb][$routeKey] = $options;
+        $this->routesNames[$verb][$name]       = $routeKey;
 
         // Is this a redirect?
         if (isset($options['redirect']) && is_numeric($options['redirect'])) {
-            $this->routes['*'][$name]['redirect'] = $options['redirect'];
+            $this->routes['*'][$routeKey]['redirect'] = $options['redirect'];
         }
     }
 
@@ -1566,12 +1622,15 @@ private function determineCurrentSubdomain()
      */
     public function resetRoutes()
     {
-        $this->routes = ['*' => []];
+        $this->routes = $this->routesNames = ['*' => []];
 
         foreach ($this->defaultHTTPMethods as $verb) {
-            $this->routes[$verb] = [];
+            $this->routes[$verb]      = [];
+            $this->routesNames[$verb] = [];
         }
 
+        $this->routesOptions = [];
+
         $this->prioritizeDetected = false;
         $this->didDiscover        = false;
     }
@@ -1638,8 +1697,7 @@ public function getRegisteredControllers(?string $verb = '*'): array
         if ($verb === '*') {
             foreach ($this->defaultHTTPMethods as $tmpVerb) {
                 foreach ($this->routes[$tmpVerb] as $route) {
-                    $routeKey   = key($route['route']);
-                    $controller = $this->getControllerName($route['route'][$routeKey]);
+                    $controller = $this->getControllerName($route['handler']);
                     if ($controller !== null) {
                         $controllers[] = $controller;
                     }
diff --git a/system/Router/RouteCollectionInterface.php b/system/Router/RouteCollectionInterface.php
index 701e893dcd16..0ca43523a89b 100644
--- a/system/Router/RouteCollectionInterface.php
+++ b/system/Router/RouteCollectionInterface.php
@@ -179,12 +179,12 @@ public function reverseRoute(string $search, ...$params);
     /**
      * Determines if the route is a redirecting route.
      */
-    public function isRedirect(string $from): bool;
+    public function isRedirect(string $routeKey): bool;
 
     /**
      * Grabs the HTTP status code from a redirecting Route.
      */
-    public function getRedirectCode(string $from): int;
+    public function getRedirectCode(string $routeKey): int;
 
     /**
      * Get the flag that limit or not the routes with {locale} placeholder to App::$supportedLocales
diff --git a/user_guide_src/source/changelogs/v4.4.0.rst b/user_guide_src/source/changelogs/v4.4.0.rst
index e340d33cc667..b4e705557979 100644
--- a/user_guide_src/source/changelogs/v4.4.0.rst
+++ b/user_guide_src/source/changelogs/v4.4.0.rst
@@ -144,6 +144,8 @@ Changes
   So if you installed CodeIgniter under the folder that contains the special
   characters like ``(``, ``)``, etc., CodeIgniter didn't work. Since v4.4.0,
   this restriction has been removed.
+- **RouteCollection:** The array structure of the protected property ``$routes``
+  has been modified for performance.
 
 Deprecations
 ************
diff --git a/user_guide_src/source/installation/upgrade_440.rst b/user_guide_src/source/installation/upgrade_440.rst
index 586097a9cc30..c82723aa129d 100644
--- a/user_guide_src/source/installation/upgrade_440.rst
+++ b/user_guide_src/source/installation/upgrade_440.rst
@@ -66,6 +66,15 @@ Interface Changes
 Some interface changes have been made. Classes that implement them should update
 their APIs to reflect the changes. See :ref:`v440-interface-changes` for details.
 
+RouteCollection::$routes
+========================
+
+The array structure of the protected property ``$routes`` has been modified for
+performance.
+
+If you extend ``RouteCollection`` and use the ``$routes``, update your code to
+match the new array structure.
+
 Mandatory File Changes
 **********************