Narrative:

Aircraft X landed on runway 28R. Aircraft X was given taxi instructions; 'turn left at kilo; right bravo; hold short of runway 28L at golf.' pilot gave a poor readback. Aircraft X then turned onto kilo; stopped short of taxiway bravo and reported holding short of 28. I reiterated taxi instructions to turn right on bravo and hold short of 28L at golf. The pilot turned on bravo and gave another poor readback. Local control asked aircraft X to verify hold short of runway 28L at golf. Aircraft X then read back his hold short instructions. Aircraft Y was cleared for takeoff on runway 28L. Before aircraft Y started his takeoff roll; aircraft X crossed the hold short bars on golf. Local control told aircraft X to hold position before aircraft X got onto the runway. Local control then cancelled aircraft Y takeoff clearance. Then; local control crossed aircraft X and ground control gave aircraft X a brasher warning. Aircraft X taxied to parking and aircraft Y departed shortly after without further incident. Pilots landing on runway 28R frequently seemed to be confused about hold short bars and which runway or taxiway they are on. When aircraft exit runway 28R at kilo and are told to hold short of runway 28L at kilo; they will often stop at the hold short bars for runway 28R instead of 28L. This can quickly block runway 28R and make it unusable. Also; if aircraft are told to taxi on bravo and hold short of runway 28L at another taxiway; they often seemed to be unsure of how far down to go. Runway and taxiway signage might need to be reevaluated to reduce pilot confusion.

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Original NASA ASRS Text

Title: Tower Controller reported an aircraft did not follow taxi instructions and caused a runway incursion.

Narrative: Aircraft X landed on Runway 28R. Aircraft X was given taxi instructions; 'turn left at Kilo; right Bravo; hold short of Runway 28L at golf.' Pilot gave a poor readback. Aircraft X then turned onto Kilo; stopped short of Taxiway Bravo and reported holding short of 28. I reiterated taxi instructions to turn right on Bravo and hold short of 28L at golf. The pilot turned on Bravo and gave another poor readback. Local Control asked Aircraft X to verify hold short of runway 28L at golf. Aircraft X then read back his hold short instructions. Aircraft Y was cleared for takeoff on Runway 28L. Before Aircraft Y started his takeoff roll; Aircraft X crossed the hold short bars on golf. Local Control told Aircraft X to hold position before Aircraft X got onto the runway. Local Control then cancelled Aircraft Y takeoff clearance. Then; Local Control crossed Aircraft X and Ground Control gave Aircraft X a brasher warning. Aircraft X taxied to parking and Aircraft Y departed shortly after without further incident. Pilots landing on Runway 28R frequently seemed to be confused about hold short bars and which runway or taxiway they are on. When aircraft exit Runway 28R at Kilo and are told to hold short of Runway 28L at Kilo; they will often stop at the hold short bars for Runway 28R instead of 28L. This can quickly block Runway 28R and make it unusable. Also; if aircraft are told to taxi on Bravo and hold short of Runway 28L at another taxiway; they often seemed to be unsure of how far down to go. Runway and taxiway signage might need to be reevaluated to reduce pilot confusion.

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.