My cardinal rule for getting around Eastern Massacusetts: If your event is in X, then stay in X.
Otherwise you leave yourself at the no-so-tender mercies of the ruthless "Boston Drivers" (of which I am a former card-carrying member). If you want to arrive for your meeting on time and not stressed-out, spend as little time driving as possible!
To get to Foxboro from Waltham, you're driving Route 128. If this is for a morning meeting, as Clint Eastwood would say, "You have to ask yourself a question, 'Do I feel lucky?'"
A lot of this is personal. For me (and many others in the Boston area), I grew up believing the breakdown lane was just a vastly underutilized alternative lane. Some of the asphalt acrobatics can really freak out some out-of-towners. It's a lot of unnecessary stress if you can avoid it.
Needham isn't as bad, so if you are TRULY opposed to the drive to Foxboro the night before, that isn't a bad alternative.
My two cents.
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"I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered. My life is my own."