Go west is the general rule of thumb for placing Troopers usually. The demogrpahics have been pretty consistent with the past two classes. This is what I noticed.
Nobody go's to the airport! The Pike I'm not sure about, they took a bunch of guys out of the last class after break in, they might do it again especially now that the Big Dig is nearly finished and they have more road.
If you live in way western mass (B Troop), you will stay there. That doesn't necessarily mean you lucked out. You might live near Springfield and have to work in Cheshire which is still and hour plus ride.
If you live in Central Mass/Metro west you will work in B Troop.
If you live in Eastern Mass (greater Boston area), you will work in C Troop (Worcester county area).
If you live North of Boston, you will work in C Troop, possibly B pending on where you live. People in the Lowell area have been known to work in B troop. If you live further east, C troop for you.
Then there's D Troop, D is for different. If you live down the cape or the Fall River/New Bedfor area, a coupleof things coud happen to you. D Troop is wierd, again D is for different. D tends to keep their own. If you have the pleasure of breaking in Dartmouth for example, based on where you live you could possibly get launched to Norwell, which is still D Troop. If you do get launched and live near the Fall River end, your probably going to end up in C troop. If you live closer to the Rte 3 area, you'll probably end up on the other side of Boston (A Troop). Brockton area tend to go towards C troop.
Anyone that breaks in H Troop, greater Boston, is not staying. You will get launched!
I hope this helps, again this is just a general observation I have seen with the last few classes. This is not gospel and anything can happen. I know guys that lived in Middleboro that worked in Lee. Or Dorchester to Springfield. Anything can happen, but in general, your usually going to have about an hour commute one way.