CESSNA 172 PVT PLT BECAME CONFUSED AND DISORIENTED DURING TAXI OUT; EVEN WITH PROGRESSIVE TAXI INSTRUCTIONS RESULTING IN TAXIING ONTO THE RWY INSTEAD OF XING AND HOLDING SHORT. TWR SENT ANOTHER ACFT ON FINAL AROUND.

Narrative

I WAS DEPARTING FROM THE EUGENE; OR; ARPT. I CALLED GND CTL AND THEY TOLD ME TO TAXI TO RWY 34 AT ALPHA 5. I INTERPRETED THIS TO MEAN THAT I SHOULD ENTER THE PARALLEL TXWY AT ALPHA 5 AND TAXI TO THE END OF THE RWY. BEING UNFAMILIAR WITH THE ARPT I CALLED 2 OTHER TIMES; FOR INSTRUCTIONS. I WAS CONFUSED AS TO MY LOCATION BUT FOLLOWED INSTRUCTIONS AS I UNDERSTOOD THEM. AS I TAXIED ONTO WHAT I THOUGHT WAS A TXWY I RECOGNIZED RWY MARKINGS BUT HAD ALREADY INADVERTENTLY CROSSED OVER THE RWY HOLD LINE OF A XING RWY. I STOPPED AND I CALLED GND AGAIN AND WAS TOLD TO MAKE A 180 DEG TURN AND TAXI BACK. AS I DID I COULD SEE THE TXWY LEADING TO RWY 34 SO I CALLED AGAIN AND ASKED IF I SHOULD TURN ONTO IT. AT THIS POINT THE CTLR TOLD ME I WOULD BE MAKING AN INTXN DEP. AFTER I DEPARTED I WAS CONTACTED BY THE TWR AND TOLD THAT ANOTHER ACFT THAT WAS LNDG DID A GAR BECAUSE THEY WERE NOT SURE I WAS GOING TO STOP AFTER I TAXIED ONTO THE RWY. IN RETROSPECT I CAN SEE THAT I WAS CONFUSED BECAUSE I DIDN'T UNDERSTAND THAT THE PHRASE 'AT ALPHA 5' MEANT I WOULD MAKE AN INTXN DEP FROM ALPHA 5. WHEN I ASKED FOR PROGRESSIVE TAXI INSTRUCTIONS I BECAME CONFUSED BECAUSE I WAS BEING DIRECTED OPPOSITE THE DIRECTION I THOUGHT I SHOULD BE GOING; BUT ASSUMED THAT I HAD JUST BECOME DISORIENTED. I WAS NOT LOOKING FOR A TXWY HOLD LINE BECAUSE I THOUGHT I WAS HEADED FOR A TXWY. ONCE I SAW THAT I WAS ON A RWY I IMMEDIATELY STOPPED AND ASKED FOR FURTHER INSTRUCTIONS. AT THIS POINT I AM NOT CERTAIN IF I WAS ON THE ACTIVE RWY THAT THE OTHER ACFT WAS LNDG ON OR THE XING RWY. I NEVER OBSERVED ANOTHER ACFT LNDG ON EITHER RWY.