Having lived through it all and seeing the outcome, the Big Dig was a pain while it was happening, but a smashing success now that itβs done. A later removal of some of the toll booths in favor of automated tolling has made the road network even more effective.
Is there still some traffic? Yes. Is it better than it was 30 years ago, even as the roads handle way more traffic? Absolutely.
I'd rather the T be functional and get me to where I need to be, and a better commuter rail system, then having to drive to and fro on Storrow at rush hour. There's no amount of bridges or expansions to the roads that would make it better short of leveling the city to build a giant highway, which I'm sure some percentage of Massachusetts drivers would be in favor of.
You prefer the T or commuter rail. That's fine and improving those modes of transit seems a fine goal as well. That preference/goal doesn't support an argument that the Big Dig solved nothing for those who choose to drive.
The only goal is to get in and out of Boston in a reasonable amount of time. I wasn't around for pre Big Dig Boston but it's still dangerous and time-consuming driving to get out of Boston by car. The Big Dig might've made it _less_ dangerous and time-consuming, but the point is the solution barely scales since the total number of people driving just increased instead. If they spent those 20 years and billions of dollars on burying and expanding the T lines, and improving the commuter rail offerings, I wager we'd have achieved a lot more towards the aforementioned goal of getting in and out of Boston quickly.
Is there still some traffic? Yes. Is it better than it was 30 years ago, even as the roads handle way more traffic? Absolutely.