Yes, there is a limit, and you hit it. The pod limit in the original version of the game is only 30 pods at a time, though there is a patch that will raise the # to 100, though on both of my PCs, it only goes to 99.
It's actually 99... so they say, looking at my game, that isn't true. I'm currently at 104.
If yer game loads slow, clean out your records "fast laps" text file. And if you build trucks or tracks, clean out all yer text files, all they do is keep records, and give your game way too much to think about.
Dunno bout tracks, but in truck making, they're in the models folder.
delete em all.