POTENTIAL CONFLICT DURING AN ALTDEV ALT OVERSHOT.

Narrative

WX WAS WORSE THAN FORECAST WITH LOW VISIBILITY AND CEILING DUE TO FOG. CTR AND APCH WERE VERY BUSY. ALL ACFT; PLTS; AND CTLRS APPEARED TO BE INTERFACING EFFICIENTLY. I WAS NBOUND ON V69 WITH A CLRNC TO THE JOT ARPT VIA JOT VOR. I AM FAMILIAR WITH THE PROCS AND AIRSPACE AS THIS IS MY HOME BASE. I WAS ASSIGNED 4000 FT AND WAS ON MY ALT BUT BECOMING UNCOMFORTABLE BECAUSE WE WERE CLOSE TO THE JOT VOR AND HAD NOT RECEIVED A LOWER ALT; CLRNC; OR VECTORS FOR APCH AS WOULD BE NORMAL. ALSO; DUE TO VOLUME OF TFC; I FOUND IT DIFFICULT TO FIND A PLACE TO 'REMIND' CTLR OF OUR POS. WE WERE VFR CONDITIONS (ABOVE OVERCAST) ON IFR FLT PLAN WHEN ON MY L I SAW AN LGT AT MY ALT. IT TOOK A MOMENT TO REACT AS THE LGT APPEARED TO TURN SLIGHTLY TOWARD ME (PERHAPS TRACKING TO THE JOT VOR). I THEN STARTED A DSCNT AS THE LGT RAISED ITS NOSE IN THE TURN THAT CROSSED IN FRONT OF ME. AS MY EYES WERE OUTSIDE I DON'T KNOW THE EXTENT OF MY ALTDEV; BUT WHEN I LOOKED BACK INSIDE (AFTER THE INCIDENT) WE WERE CLBING AND 250 FT BELOW ASSIGNED ALT. DURING THIS TIME; I XMITTED OUR CONCERN REGARDING THE 'HVY' AT OUR 9 O'CLOCK POS AND XING. I WAS THEN VECTORED NW AND DSNDED FOR THE APCH WITHOUT INCIDENT. SUGGESTIONS: JET ACFT SHOULD NOT BE OPERATING BELOW 12000 FT THAT FAR FROM THEIR DEST. AS MY HOUSE IS LOCATED NEAR THIS PLACE; I CONSTANTLY SEE AIR TRANSPORT TYPE ACFT OPERATING AT 5000 FT. OCCASIONALLY IT APPEARS TO BE LOWER AND HAVE OFTEN REMARKED THAT THIS IS A TIME BOMB SITUATION. WOULDN'T IT HAVE BEEN IRONIC IF I WOULD HAVE BEEN PART OF THAT BOMB. OUR PRESENT TCA SYS THAT BRINGS MIXED TFC TOGETHER AT LOW ALTS IS RIDICULOUS.