Unauthorized key

I am trying to run the first example on http://www.mapquestapi.com/traffic/

http://www.mapquestapi.com/traffic/v2/incidents?key=YOUR_KEY_HERE&boundi...

I am receiving an unauthorized key error when I try to use one of my keys.

{"incidents":[],"mqURL":"&latitude=NaN&longitude=NaN","info":{"copyright":{"text":"© 2015 MapQuest, Inc.","imageUrl":"http://api.mqcdn.com/res/mqlogo.gif","imageAltText":"© 2015 MapQuest, Inc."},"statuscode":403,"messages":["This key is not authorized for this service. If you do not have a key, you can obtain a free key by registering at http://developer.mapquest.com."]}}

On the pricing & plans page, the Traffic API should be available for all plans so any help would be appreciated. I have tested the key with different APIs and it works fine.

Thank you,
Adam