Narrative:

Ground control instructed me to back taxi on closed runway 04 to intersecting active runway 31L. Arriving at runway 31L I became confused because of multiple hold short lines on 2 perpendicular taxiways G and north intersecting the 2 perpendicular runways 04/31L. There are 6 hold short lines in near proximity on the taxiways and runways at these intersections. The painted lines on both runways are weathered and partially obscured with rubber tire marks. I mis-interpreted the hold short line on runway 04 to runway 31L. I turned on to active runway 31L to stop at the hold short line for runway 04. I checked in with the tower. Then I told tower I thought I was on runway 31L. The response was to hold short. Soon I was cleared for takeoff.upon departure I was instructed to call either of 2 phone numbers for possible pilot deviation. I've called both numbers 5 days in a row with no answer and no return phone call. I have since studied aerial photos and airport diagrams. I now see my error of mistaking which hold short line was intended for which runway. Study airport diagram better and request a progressive taxi from ground control at unfamiliar airports.

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Original NASA ASRS Text

Title: Corporate pilot reported crossing runway hold short line due to confusing instructions and unclear signage at SAT.

Narrative: Ground control instructed me to back taxi on closed runway 04 to intersecting active runway 31L. Arriving at runway 31L I became confused because of multiple hold short lines on 2 perpendicular taxiways G and N intersecting the 2 perpendicular runways 04/31L. There are 6 hold short lines in near proximity on the taxiways and runways at these intersections. The painted lines on both runways are weathered and partially obscured with rubber tire marks. I mis-interpreted the hold short line on runway 04 to runway 31L. I turned on to active runway 31L to stop at the hold short line for runway 04. I checked in with the tower. Then I told tower I thought I was on runway 31L. The response was to hold short. Soon I was cleared for takeoff.Upon departure I was instructed to call either of 2 phone numbers for possible pilot deviation. I've called both numbers 5 days in a row with no answer and no return phone call. I have since studied aerial photos and airport diagrams. I now see my error of mistaking which hold short line was intended for which runway. Study airport diagram better and request a progressive taxi from ground control at unfamiliar airports.

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.