Date: 201906
Local time of day: 1201-1800
Location: LAX.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class B LAX
ATC / advisory: Tower LAX
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Distraction; Situational Awareness; Confusion
Second reporter function: Pilot Flying; First Officer
Anomaly: Ground Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: Other Takeoff
Result: Flight Crew Overcame Equipment Problem
Contributing factors: ATC Equipment / Nav Facility / Buildings
Primary problem: ATC Equipment / Nav Facility / Buildings

Narrative: We were given a clearance to line up and wait as the preceding aircraft began its takeoff roll then proceeded into position on the runway. As the preceding aircraft lifted off; we were given our takeoff clearance. After verifying the runway heading; I transferred the controls to my FO and he initiated the takeoff by advancing the thrust levers and calling; 'Check thrust.'  I moved my hand to the thrust levers and scanned the engine instruments.  After verifying thrust and other indications; I called; 'Thrust set.'  At this point; I returned my attention to the runway and was surprised to see the red runway status lights along the center line were illuminated.  I looked down the runway to see if there was any threat and saw none.  I thought that perhaps the lights had remained on from the departure of the previous aircraft and was considering rejecting the takeoff when the lights extinguished.  From the time I first noticed the lights being on until they went out was only about 2 or 3 seconds.  With the lights having gone out and no known threat; I elected to continue the takeoff which was completed normally.  Later in the flight; we discussed the incident.  My FO confirmed that the lights were off when we began our takeoff roll and came on for only a few seconds.Both pilots were surprised and confused by the lights coming on when they did.  I'm not sure if this was a malfunction of the automated RWSL [Runway Status Lights] system or if perhaps the system properly detected an aircraft rapidly approaching the runway at an intersection down field.  If this was not a malfunction and was caused by a rapidly approaching taxiing aircraft; further events could be reduced through pilot education.


Second narrative: During the takeoff roll; at approximately 80 knots; the Runway Status Lights momentarily flashed red.  Before I could react to or announce what I saw; the lights extinguished. Seeing no threat visually we continued the takeoff.Unknown as to why the status lights flashed briefly; as no traffic was crossing.  We took off behind a preceding A320 and no aircraft had crossed or were cleared to cross. The momentary nature of the status light appeared to be a malfunction.In retrospect; we should have rejected the takeoff and confirmed the status lights had operated in error.


Synopsis: ERJ-175 flight crew reported Runway Status Lights unexpectedly activated momentarily during their takeoff roll.