Narrative:

Working local control and controller in charge (controller in charge). Aircraft X was #1 for departure at runway 21. An airport vehicle was behind him waiting to do a runway inspection. I departed aircraft X on course VFR to the south then started the airport vehicle down the runway full length from B5; flipping my runway status indicator to red and turning the 21 flasher on. Not to long after that aircraft Y was on the K side to depart runway 21. There was a couple IFR inbounds from the west-southwest so I coordinated with my approach controller to leave me runway heading for one departure. After getting approval for that I went back and cleared aircraft Y for takeoff on runway heading. After the departure was airborne and climbing out they informed me that there was a vehicle on the runway. [The airport vehicle] was down by B2 and it appeared like he heard the transmission and cleared the runway at B2 on his own and requested to go to runway 9/27 on B. I coordinated that with my ground controller and had the airport vehicle contact him. I didn't see the truck down where it was during my scan; and even though I was using the required memory aids; I suppose I became complacent and slightly preoccupied with working out the separation for the inbounds radar had and my departure off 21. I need to be more deliberate with my scan out the window; I could have used binoculars for that end since it gets pretty far out to quickly identification a vehicle. If I had done a better job with that I would have caught the vehicle on the runway even though I missed the runway flipper and flasher.

Google
 

Original NASA ASRS Text

Title: FSD Tower Controller reported a runway incursion with an aircraft departing and an approved truck on the closed runway. Controller was using memory joggers; but departed traffic anyway.

Narrative: Working Local Control and Controller in Charge (CIC). Aircraft X was #1 for departure at runway 21. An airport vehicle was behind him waiting to do a runway inspection. I departed Aircraft X on course VFR to the south then started the airport vehicle down the runway full length from B5; flipping my runway status indicator to red and turning the 21 flasher on. Not to long after that Aircraft Y was on the K side to depart runway 21. There was a couple IFR inbounds from the west-southwest so I coordinated with my approach controller to leave me runway heading for one departure. After getting approval for that I went back and cleared Aircraft Y for takeoff on runway heading. After the departure was airborne and climbing out they informed me that there was a vehicle on the runway. [The airport vehicle] was down by B2 and it appeared like he heard the transmission and cleared the runway at B2 on his own and requested to go to runway 9/27 on B. I coordinated that with my ground controller and had the airport vehicle contact him. I didn't see the truck down where it was during my scan; and even though I was using the required memory aids; I suppose I became complacent and slightly preoccupied with working out the separation for the inbounds radar had and my departure off 21. I need to be more deliberate with my scan out the window; I could have used binoculars for that end since it gets pretty far out to quickly ID a vehicle. If I had done a better job with that I would have caught the vehicle on the runway even though I missed the runway flipper and flasher.

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.