Narrative:

We were cleared to line up and wait on runway 25R at lax. Upon entering the runway; we were cleared RNAV dockr; cleared for takeoff runway 25R. Takeoff checklist was completed and power was applied. The 80 knot call was made and checked. At approximately 125 knots we realized that a plane appeared to be crossing at the far end of the runway. Judging our speed and rate of acceleration and the distance between our aircraft; the decision to continue the takeoff was made. In my judgement; this was the safest course of action not knowing the stopping distance that would be required and feeling confident in our ability to clear the aircraft if it did not completely cross the runway before we reached it. We executed a normal rotation. The aircraft exited the runway before we crossed its path on the runway by a margin of perhaps 75 feet. Several factors contributed to this event. First would be the either inadvertent clearing of an aircraft to cross a runway that was already in use for a takeoff; or a crew mistakenly crossing a runway without clearance. We heard no radio call clearing another aircraft across our runway. Another factor would be the time of day and weather conditions. [The] incident occurred approximately [half hour after sunset]. Adding to that was the weather. FEW000 was really more like patchy fog toward the far end of the runway towards the pacific [ocean] and the point of entry for the conflicting aircraft; making its detection more difficult.continued emphasis on runway incursion events and there avoidance is certainly in order. The installation of red do not cross lights at runway and taxiway intersections would prove helpful though we would have been well past the runway lights when the crossing began; it would have proved helpful for the other aircraft.

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Original NASA ASRS Text

Title: B737 flight crew reported observing an aircraft crossing downfield during takeoff roll from LAX.

Narrative: We were cleared to line up and wait on Runway 25R at LAX. Upon entering the runway; we were cleared RNAV DOCKR; cleared for takeoff Runway 25R. Takeoff Checklist was completed and power was applied. The 80 knot call was made and checked. At approximately 125 knots we realized that a plane appeared to be crossing at the far end of the runway. Judging our speed and rate of acceleration and the distance between our aircraft; the decision to continue the takeoff was made. In my judgement; this was the safest course of action not knowing the stopping distance that would be required and feeling confident in our ability to clear the aircraft if it did not completely cross the runway before we reached it. We executed a normal rotation. The aircraft exited the runway before we crossed its path on the runway by a margin of perhaps 75 feet. Several factors contributed to this event. First would be the either inadvertent clearing of an aircraft to cross a runway that was already in use for a takeoff; or a crew mistakenly crossing a runway without clearance. We heard no radio call clearing another aircraft across our runway. Another factor would be the time of day and weather conditions. [The] incident occurred approximately [half hour after sunset]. Adding to that was the weather. FEW000 was really more like patchy fog toward the far end of the runway towards the Pacific [Ocean] and the point of entry for the conflicting aircraft; making its detection more difficult.Continued emphasis on runway incursion events and there avoidance is certainly in order. The installation of red do not cross lights at runway and taxiway intersections would prove helpful though we would have been well past the runway lights when the crossing began; it would have proved helpful for the other aircraft.

Data retrieved from NASA's ASRS site 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.