ACR HAS TO TAKE EVASIVE ACTION CLB TO AVOID ACFT OUTBOUND FROM VOR.

Narrative

AFTER BEING VECTORED OFF OUR NORMAL COURSE (BROADWAY VOR DIRECT SPARTA; HDG 055 DEG MAGNETIC) TO A HDG OF 020 DEGS; WE WERE NW OF SPARTA VOR (AT 3000 FT MSL) WHEN TOLD 'DIRECT SPARTA; CONTINUE ON COURSE.' THIS REQUIRED A R TURN TO ABOUT 130 DEGS MAGNETIC. WE WERE ABOUT 6.0 DME NW OF SPARTA. AS WE APCHED THE VOR; I NOTICED TFC CONVERGING OVER THE VOR AT ABOUT 2900 FT. WE CALLED THE TFC TO ATC; WHO SAID THAT IT WAS INDICATING 3300 FT. I TOLD ATC THAT THE TFC WAS AT ABOUT OUR ALT; AND APPEARED TO BE OUTBOUND ON OUR COURSE. I ASKED ATC WHAT HE WANTED US TO DO. I WAS TOLD 'TURN L; OR YOU CAN CLB IF YOU WANT TO.' I TOLD ATC THAT WE WERE CLBING. THE OTHER ACFT CONTINUED OUTBOUND (ABOUT 080 DEGS) BUT THEN STARTED A R TURN. WE STOPPED OUR CLB AT 3500 FT; AND STAYED THERE UNTIL WE PASSED HIM; THEN RETURNED TO 3000 FT; INFORMING ATC. I REALLY DO NOT UNDERSTAND WHY THE HDG OF 020 DEGS AND ALSO THE DSCNT TO 3000 FT OCCURRED. IT PLACED US IN A POS OF BEING AT THE MOST POPULAR VFR ALT IN THE WORLD IN AN AREA JUST OUTSIDE THE TCA (CLASS B) AT THE VERY BOTTOM OF THEIR EFFECTIVE RADAR COVERAGE. LGA ROUTINELY ASSIGNS THE ALT OF 3000 FT IN THAT AREA; BUT 9 TIMES OUT OF 10; ONE CAN STAY AT 4000 FT FOR ABOUT AN ADDITIONAL 20 MI. IT IS POSITIVELY DANGEROUS TO MIX VFR PRACTICE AREAS AND SCHEDULED ACRS. THERE WILL BE AN ACCIDENT. OH YES; NO TCASII ON OUR ACFT.