That's a good distance for a commute. Mine is 25 miles RT, and a couple of miles of it is on a freeway shoulder--there's no alternate route. It's legal and the bike lane is marked with paint, but you're right out there with the 70mph semis. All it would take is one second of inattention and you're stuck on the grill with the dead birds and June bugs. It's especially bad coming home uphill, because you can only do 10 or 12mph. If I could skip that part, I'd probably ride twice as often.