Bostonist: Big Dig Speeds Commutes, But Damn, It Sure Was Expensive

Kaleberg

Sat, 18 Feb 2006 12:50:32 -0500

The big return on investment will not be in reduced commuting time, but in increased traffic handling as the commuting time returns to it's pre-Big Dig equilibrium. I know that this is really awful, so enjoy the fast ride while you can. Eventually, people will realize that they CAN live on the North Shore and work towards the South Shore (or vice versa), so they'll start shuffling jobs, and new jobs will be created in new areas because they will have a larger workforce catchment area. Traffic congestion will increase, but tax revenues from all the development and new jobs will rise as well. That's what will make the Big Dig pay off. Remember, the Romans rebelled when asked to pay for the big Tarquin sewer project, but they are still using that old sewer system today.

Rod Begbie

Wed, 15 Feb 2006 22:11:12 -0500

If you take into account that the people who drive into Boston for work are probably at the high-end of the MA average wage, it's probably really only 60 years til it pays for itself.

Ezra

Wed, 15 Feb 2006 14:03:06 -0500

OK, this is fun. So, in addition to productivity gains, you probably need to also account for productivity *losses* due to everything being a mess for 15 years. I know you said you were just going to limit your equation to productivity gains. But one other number that it would be realtively easy to get a less-than-precise but interesting number is in gas consumption. Assume that all 203,500 cars were cars, and actually got the CAFE-required 27.5 MPG (so, no light or heavy trucks, which include SUVs). Also assume an average speed of 20 MPH (which I just pulled out of thin air). That means a savings of 41,193 gallons of gas, or about $99K. Wow. That didn't add up to much. Even if I use an average MPG of 15 to factor in SUVs, I still only get about $182K.