Narrative:

Origination and taxi out were standard. Tower cleared us for takeoff. I advanced the thrust and called 'set power.' shortly thereafter I observed another carrier crj quickly approaching the runway on the taxiway. I pulled the thrust to idle; called for an abort and transferred the controls to the captain. We exited the runway and brought the aircraft to a safe stop on the taxiway. We conducted the aborted takeoff checklist; reviewed the brake cooling procedure and returned for a departure after 15 minutes. The remainder of the flight was conducted standard. Abort was conducted as soon as it was obvious that the crj was taxiing onto the runway.

Google
 

Original NASA ASRS Text

Title: A CRJ-200 First Officer initiated a rejected takeoff when he noted another CRJ encroaching on their runway at high speed.

Narrative: Origination and taxi out were standard. Tower cleared us for takeoff. I advanced the thrust and called 'set power.' Shortly thereafter I observed another carrier CRJ quickly approaching the runway on the taxiway. I pulled the thrust to idle; called for an abort and transferred the controls to the Captain. We exited the runway and brought the aircraft to a safe stop on the taxiway. We conducted the Aborted Takeoff Checklist; reviewed the brake cooling procedure and returned for a departure after 15 minutes. The remainder of the flight was conducted standard. Abort was conducted as soon as it was obvious that the CRJ was taxiing onto the runway.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.