Yeah the SH 88 and SH 21 cross right in the middle of Periyapatna. You have a church, a post office and a bus stand there, but other than that there are only meager residential layouts. But the area is improving, so it could be a good idea to invest now.
Actually I guess it depends on what type of investment you are looking at. Since it is not a place near to the city, I guess investing in industrial and commercial spaces makes sense.
Periyapatna is right on the outskirts of Mysore ....its actually a small area where two State highways cross. I guess that could be a good reason to invest here.