Small Aircraft
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) .4
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Air Traffic Control Provided Assistance
Human Factors
Aircraft X wanted to taxi from [FBO] located on the north side of the airport to his hangar located on the south side. Due to [FBO] offering the cheapest fuel on the airfield; multiple parallel runway crossings with Local North and Local South Controller occur during times of heavy traffic regardless of where their hangars are located. Aircraft X was instructed at first to taxi onto Charlie and hold short of Bravo while other aircraft were requesting taxi instructions. I then told Aircraft X to cross Runway 17 on Charlie and hold short of 27R on Alpha. I let Local North (27R) controller know that taxiway Alpha was blocked; due to an aircraft landing [27L] in case he needed to exit the runway onto Alpha. Local North could not get the instructions to aircraft out in time to continue taxiing down the runway. The landing aircraft exited on Alpha. I then told Aircraft X to hold short of 27L on Bravo to prevent a nose to nose situation. Aircraft X read back hold short 27L on Bravo and then questioned if he could cross Runway 27R. I was offline coordinating with Local North controller to request to cross 27R after departing traffic while other aircraft called requesting for taxi. I did not catch transmission right away and Aircraft X crossed 27R while departing aircraft was taxiing onto the runway for departure. I issued brasher warning to Aircraft X and he called the Tower saying he was instructed to hold short 27L on Bravo. He took that as permission to cross Runway 27R.I recommend that the FBOs come to an agreement on a general price of fuel range on the airfield. I understand it is a business and they are competing; but the ground traffic complexity is amplified due to the amount of opposite direction parallel runway crossings that happen during busy times of traffic. We try to use the first come; first serve basis but a lot of pilots become irate when they are waiting for long periods of time due to not being the priority. Also; if the pilot questions an instruction; maybe it is better to go back and verify than assume.
SEE Ground Controller reported a runway incursion attributed to aircraft taxiing to different FBO's for cheaper gas prices on the airport.