Skyhawk 172/Cutlass 172
Air Traffic Control Developmental
Confusion; Situational Awareness
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Human Factors
I had just put C172 in position on Runway 31. There was a lot of discussion in the Tower related to some new RNAV procedures we are currently implementing. I wasn't involved in the discussion but from the midst of the discussion; Ground asked to cross Runway 31. I think the Coordinator also asked about the crossing at the same time because I had multiple voices addressing me at the same time. I was focusing on an aircraft I had just cleared for takeoff on with the intent of clearing C172 in position on Runway 31 to turn behind him. I had a couple other aircraft queuing up for 31. I authorized the runway crossing; but promptly forgot. I had C172 in my peripheral vision as I was trying to gauge an appropriate time to launch behind the regional jet off of 2R. I cleared C172 for takeoff to a 090 heading. The pilot immediately said; 'I've got a Lear in front of me.' I canceled his take off clearance. He never began takeoff roll. When the Lear was clear; I cleared the aircraft for takeoff without incident. I would recommend to myself to use some sort of visual aid or memory jogger for all runway crossings regardless of traffic. We do not have a mandatory aid or policy on using aids at our facility. We do have some runway closed strips that I have used in the past and will now use in the future. Also in my hurry I neglected to use an appropriate runway scan.
Local Controller approved a vehicle runway crossing of the active and then cleared an aircraft for takeoff forgetting about the vehicle crossing.