Narrative:

Possible runway incursion. Mdw tower cleared us to exit left onto the next taxiway (Q) (the taxiway was not identified) and hold short of 4L traffic on final. We looked for a line to indicate hold short of 4L and did not find one on taxiway Q. We continued onto taxiway november (north), but still did not find a line that looked like short of 4L. I asked tower if we could continue onto taxiway papa (P) and hold short of 4R (because we didn't see the line, this was not transmitted). Tower approved of going onto papa. Then stated we had crossed 4L, but that it was ok because the traffic was still on short final. When we got onto ground, we asked if there was a line on Q to hold short of 4L. He said there was a line but it was difficult to see and the signage was also poor. He also said that where we taxied we were actually not on 4L. The line he said was actually there for aircraft with longer wingspans. We did not actually get onto 4L, in my opinion also. We were clear onto taxiway papa well before the landing traffic got onto the runway. It would have been better understood in our aircraft if the tower controller had said turn onto taxiway Q and hold short of runway 4L on taxiway Q. That would have cleared up our instructions and we would not have had to look for the poorly marked area used for holding short. Supplemental information from acn 556398: possible runway incursion. Landed on runway 4R at mdw and was told by tower to turn left and hold short of runway 4L for landing traffic. I read back his instructions and he repeated to hold short of runway 4L. We turned left at Q onto north and around on P. The captain asked tower if he wanted us to hold short of runway 4R at P. The tower said he had wanted us to hold short of 4L, but neither the captain or myself felt we had crossed any hold short lines for runway 4L. After switching to ground control we asked about the hold line and was told that it was hard to discern and that some aircraft with large wingspans will actually cross the hold short line with their wings. Whether we did or not cross the line with our wing, I'm not sure. Obviously you need to reference the 10-9 page to see what I am referring to. I don't believe ATC was overly concerned about this incident, but to prevent future possible incursions, it might help if the controller said hold short of runway 4L on north. And it would help if they made the hold short line easier to spot.

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Original NASA ASRS Text

Title: B737-300 CREW HAD A RWY INCURSION TURNING OFF RWY 4R ONTO TXWY Q, N AND P AT MDW.

Narrative: POSSIBLE RWY INCURSION. MDW TWR CLRED US TO EXIT LEFT ONTO THE NEXT TXWY (Q) (THE TXWY WAS NOT IDENTIFIED) AND HOLD SHORT OF 4L TFC ON FINAL. WE LOOKED FOR A LINE TO INDICATE HOLD SHORT OF 4L AND DID NOT FIND ONE ON TXWY Q. WE CONTINUED ONTO TXWY NOVEMBER (N), BUT STILL DID NOT FIND A LINE THAT LOOKED LIKE SHORT OF 4L. I ASKED TWR IF WE COULD CONTINUE ONTO TXWY PAPA (P) AND HOLD SHORT OF 4R (BECAUSE WE DIDN'T SEE THE LINE, THIS WAS NOT TRANSMITTED). TWR APPROVED OF GOING ONTO PAPA. THEN STATED WE HAD CROSSED 4L, BUT THAT IT WAS OK BECAUSE THE TFC WAS STILL ON SHORT FINAL. WHEN WE GOT ONTO GND, WE ASKED IF THERE WAS A LINE ON Q TO HOLD SHORT OF 4L. HE SAID THERE WAS A LINE BUT IT WAS DIFFICULT TO SEE AND THE SIGNAGE WAS ALSO POOR. HE ALSO SAID THAT WHERE WE TAXIED WE WERE ACTUALLY NOT ON 4L. THE LINE HE SAID WAS ACTUALLY THERE FOR ACFT WITH LONGER WINGSPANS. WE DID NOT ACTUALLY GET ONTO 4L, IN MY OPINION ALSO. WE WERE CLR ONTO TXWY PAPA WELL BEFORE THE LNDG TFC GOT ONTO THE RWY. IT WOULD HAVE BEEN BETTER UNDERSTOOD IN OUR ACFT IF THE TWR CTLR HAD SAID TURN ONTO TXWY Q AND HOLD SHORT OF RWY 4L ON TXWY Q. THAT WOULD HAVE CLRED UP OUR INSTRUCTIONS AND WE WOULD NOT HAVE HAD TO LOOK FOR THE POORLY MARKED AREA USED FOR HOLDING SHORT. SUPPLEMENTAL INFO FROM ACN 556398: POSSIBLE RWY INCURSION. LANDED ON RWY 4R AT MDW AND WAS TOLD BY TWR TO TURN L AND HOLD SHORT OF RWY 4L FOR LNDG TFC. I READ BACK HIS INSTRUCTIONS AND HE REPEATED TO HOLD SHORT OF RWY 4L. WE TURNED L AT Q ONTO N AND AROUND ON P. THE CAPT ASKED TWR IF HE WANTED US TO HOLD SHORT OF RWY 4R AT P. THE TWR SAID HE HAD WANTED US TO HOLD SHORT OF 4L, BUT NEITHER THE CAPT OR MYSELF FELT WE HAD CROSSED ANY HOLD SHORT LINES FOR RWY 4L. AFTER SWITCHING TO GND CTL WE ASKED ABOUT THE HOLD LINE AND WAS TOLD THAT IT WAS HARD TO DISCERN AND THAT SOME ACFT WITH LARGE WINGSPANS WILL ACTUALLY CROSS THE HOLD SHORT LINE WITH THEIR WINGS. WHETHER WE DID OR NOT CROSS THE LINE WITH OUR WING, I'M NOT SURE. OBVIOUSLY YOU NEED TO REFERENCE THE 10-9 PAGE TO SEE WHAT I AM REFERRING TO. I DON'T BELIEVE ATC WAS OVERLY CONCERNED ABOUT THIS INCIDENT, BUT TO PREVENT FUTURE POSSIBLE INCURSIONS, IT MIGHT HELP IF THE CTLR SAID HOLD SHORT OF RWY 4L ON N. AND IT WOULD HELP IF THEY MADE THE HOLD SHORT LINE EASIER TO SPOT.

Data retrieved from NASA's ASRS site as of July 2007 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.