What is the fastest way to get from Medford to Marlborough?

I'm starting a job in Marlborough, MA but live in Medford. Considering traffic, which is the fastest route: 93 south to 90 west (about 3.5 miles on 93 south heading into the city in the mornings), 93 north to 495 south, or rt 2 to 95 south to 20 west. I like the expressway to the pike idea but how long will I spend on 93 south in the mornings?