Commuter rail from N. Leominster to Porter is 24.50 round-trip + $4 for parking + ~$5 round-trip for the T. That's still cheaper than driving in for a day which would be about $50 round trip using IRS rates plus parking which could easily be $30+. (I'll drive in the evening or weekend when driving/parking are easier/quicker and the commuter rail really isn't very practical for an evening event.)