Drupal has a default function which called "aliases URL" to allow user to change and point URL /node/XX to /OOO (XX is node ID, OOO could be any name).
However, drupal won't remove original URL so it will have duplicate redirects to the same page.

Duplicate redirects are not only increasing the workload of website, it could also cause sandboxed effect for search engines.

There is a exist drupal module could solve this problem and improve preformance of your drupal website.
By using Global Redirect, it interrupts the page load and the a alias lookups. If any of the aliases rules apply then the appropriate action is taken.
If no rules apply then the page load continues uninterrupted.

What dose this module do?

According to its description:
" GlobalRedirect is a simple module which…

Checks the current URL for an alias and does a 301 redirect to it if it is not being used.
Checks the current URL for a trailing slash, removes it if present and repeats check 1 with the new request.
Checks if the current URL is the same as the site_frontpage and redirects to the frontpage if there is a match.
Checks if the Clean URLs feature is enabled and then checks the current URL is being accessed using the clean method rather than the 'unclean' method. "

For more detail: http://drupal.org/project/globalredirect
Sandboxed effect (wiki link): http://en.wikipedia.org/wiki/Sandbox_Effect