Narrative:

I was working local west and local east combined. Ground control/flight data was combined with controller in charge. Local assist was staffed. Traffic levels were very low. City vehicle called from B10 (south end of runway 13R) to proceed north on the runway for a routine inspection. I cleared city vehicle to proceed north on runway 13R. I then returned to a conversation with flight data controller referencing an interesting aircraft at an FBO ramp.sometime later; I estimate 1 minute; aircraft X called ready for a (west) departure from runway 13R full length. I did a cursory scan of 13R; as I usually do; then cleared him for takeoff. A few moments later aircraft X said 'tower there's a vehicle on the runway!' I scanned and observed aircraft X in position; but not moving and city vehicle northbound; almost to B3 (approximately 3;000 feet from aircraft X). I immediately instructed city vehicle to exit the runway at B3; which he was already rapidly doing. I immediately informed the controller in charge of the error then re-scanned runway 13R and again cleared aircraft X for takeoff. At which point aircraft X departed without further incident. During this incident aircraft X had never started a takeoff roll. After the aircraft departed I realized that I had never activated the rid (runway incursion device) for runway 13R. Our policy clearly states to do so. I don't have any recommendations per say. But I do know that from now on I will always use the rid when I have a vehicle on the runway. Additionally I will use our 'high chair'; which allows scanning the middle portion of the runaway. It is very difficult to do so in the lower; more comfortable chairs that we usually use. During my 1st scan of the runway I was unable to see the middle portion or the runway due to tower cab equipment. This is a hot spot if you sit low. And a very poor practice to fall into; just sitting back; not standing to check the blind spot; which I estimate is exactly where city vehicle was when I cleared aircraft X.

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Original NASA ASRS Text

Title: BFI controllers described a runway incursion involving a departing cleared for takeoff small aircraft and a vehicle that was already approved to be on the runway. The Controller did not use the RID (Runway Incursion Device) when he allowed the vehicle onto the runway. Pilot advised Tower of traffic on runway; Controller removed the vehicle off the runway and the aircraft departed.

Narrative: I was working Local West and Local East combined. Ground Control/Flight Data was combined with CIC. Local Assist was staffed. Traffic levels were very low. City vehicle called from B10 (south end of RWY 13R) to proceed north on the runway for a routine inspection. I cleared city vehicle to proceed north on RWY 13R. I then returned to a conversation with Flight Data controller referencing an interesting aircraft at an FBO ramp.Sometime later; I estimate 1 minute; Aircraft X called ready for a (west) departure from RWY 13R full length. I did a cursory scan of 13R; as I usually do; then cleared him for takeoff. A few moments later Aircraft X said 'Tower there's a vehicle on the runway!' I scanned and observed Aircraft X in position; but not moving and city vehicle northbound; almost to B3 (approximately 3;000 feet from Aircraft X). I immediately instructed city vehicle to exit the runway at B3; which he was already rapidly doing. I immediately informed the CIC of the error then re-scanned RWY 13R and again cleared Aircraft X for takeoff. At which point Aircraft X departed without further incident. During this incident Aircraft X had never started a takeoff roll. After the aircraft departed I realized that I had never activated the RID (Runway Incursion Device) for RWY 13R. Our policy clearly states to do so. I don't have any recommendations per say. But I do know that from now on I will always use the RID when I have a vehicle on the runway. Additionally I will use our 'high chair'; which allows scanning the middle portion of the runaway. It is very difficult to do so in the lower; more comfortable chairs that we usually use. During my 1st scan of the runway I was unable to see the middle portion or the runway due to tower cab equipment. This is a hot spot if you sit low. And a very poor practice to fall into; just sitting back; not standing to check the blind spot; which I estimate is exactly where city vehicle was when I cleared Aircraft X.

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.