The MBTA has been shutting down parts of the T in order to accelerate some of the work the agency says is necessary to improve safety and reliability on the system. WGBH Morning Edition Host Joe Mathieu spoke with Secretary of Transportation Stephanie Pollack about the state's efforts to improve the MBTA. The transcript below has been edited for clarity.

Joe Mathieu: Weekend closures on the T have been underway for weeks now. You have laid a lot of new track and you've refurbished some stations. You call it accelerated work. How much have you managed to get done?

Sec. Stephanie Pollack: So we get a lot more done when we can work on the weekends. And that's why even though it inconveniences our customers — including me, I've been taking shuttle buses sometimes instead of the Green Line D line — it really does let us fix the system faster. We understand everyone's frustration, both with the traffic on the roads and the condition of the T and the sense of urgency, but for us to fix things faster, it does mean we'll be inconveniencing folks.

Mathieu: So we're starting work on the Red Line now this weekend. You're specifically working on Park Street and Downtown Crossing stations, which are extremely busy. A lot of us have spent a lot of time on those platforms. What's specifically the job you'll be doing there?

Pollack: So there's track down in what we call "the pit" — that's what you look down on when you're standing on the platform — that hasn't been replaced in decades. There's work that needs to be done on the stations themselves that we can't do when our customers [are] there. But a lot of the work is just the nitty-gritty parts of the system: the track, the signals, the power supply. Those are the things that are really hard to fix when the system is open, but those are the things that when they break, they ruin your commute.

Mathieu: So you're talking about track in the pits [that's] 30 years old, I read. What does the new track do? Is it a smoother ride or are we actually preventing things like derailments?

Pollack: So it's three things. It's safety [and] preventing derailments. The better the track and the bottom of the train connect to each other, the safer the ride is. It's reliability, because problems with the track, signals or the powers cause hiccups during the commuting day, and that's when you get those announcements [that] we're holding the trains or there's a delay because of a disabled train. And to some extent, it is speed. So on the Green Line, which we've also been closing on the weekends and running shuttle buses, the new track allows us to actually run the trains faster because we can run them safely and run them faster. And that does shorten people's trips.

Mathieu: As work continues on the T, the Baker administration is proposing a much more comprehensive approach to fixing the state's transportation infrastructure. We've talked about this a lot with the governor. I'd like to ask you about it because we're talking roads, we're talking bridges, we're talking every way we move around here. You're asking the legislature to approve a multi-billion dollar bond bill to pay for it. Where does that stand?

Pollack: The governor filed the bond bill in August. We haven't really done a comprehensive package that looks at our transportation system since 2014. And obviously the good news is the state is thriving. We have more workers, we have more residents and we have more jobs. So it feels a lot more crowded even than five years ago. So we filed it [and] the Legislature was kind enough to schedule an early hearing. So we've already had our hearing, and we plan to work with our colleagues in the legislature — they're on break after next week till the end of the year — but we're hoping in January we'll be able to move both our package and any other transportation-related legislation that the legislature is interested in getting done this year.

Mathieu: This seems to be one of the big ideas from the Baker administration. I know he is dealing with health care proposals and so forth, but this is huge for transportation, right? If you get that money, what can you do with it?

Pollack: People have said, and we hear loud and clear, can't you fix things faster? Can't you fix more of our roads and bridges? Can't you fix the T faster? Can't you help the smaller transit authorities outside the MBTA — cities and towns who have roads and bridges in bad shape and budgets that it's hard to stretch to cover them?

The bond bill really covers all the different kinds of transportation for all 351 cities and towns in the state. It would let us ramp up spending to fix deficient bridges faster. It would let us get roads paved faster so you don't get those potholes and holes in bridge decks that always seem to open up right at rush hour and ruin traffic. Cities and towns own a lot of our roads and bridges, and they've got really tight budgets. We do have programs to get them resources, but the bond bill would allow us to give more. We also know that people want more ways to walk and bike safely, and maybe use water transportation and not always have to be stuck in traffic for every trip they make. So there is money in the bond bill for more buses, for cleaner electric buses, for water transportation, for beginning the process of taking our commuter rail system and making it a more frequent system that people can use for more than just commuting.

Mathieu: There's been a lot of talk about managed lanes [and] whether we should be tolling. We have surge pricing in tolling. There are a lot of different ideas that are being floated. The governor was not a fan of the surge tolling, as he made clear. And he's receiving some criticism — maybe you are, too — about adding lanes to highways. People point to studies that show they simply fill up and everyone's stuck in traffic again. Can you speak to that? What's going to happen with the highways? Do we need to increase capacity or tolling?

Pollack: I'm a pragmatist, not an ideologue when it comes to it. There are places where we absolutely need to rebuild highways and add lanes. Anyone who thinks we don't need to add lanes on the Bourne and Sagamore bridges to get people to the Cape has not sat in traffic trying to get to the Cape for most of the year. So we have an opportunity working with the Army Corps to add lanes there. We're rebuilding the intersection of the turnpike and 495 out in central Massachusetts in a way that will make it easier for both cars and trucks to navigate that very complicated interchange safely.

So we know there are pinch points in the system, bottlenecks, where if we don't uncork them, people are just going to be sitting in traffic. That's said, we're not going to build our way out of congestion. That can't be our only strategy. We added one lane on Route 128, spent $400 million over a decade building it. I don't think that's what people mean when they say, 'Can't you help me with traffic congestion?' So a big part of it is going to be investing in transit, walking and biking to give people the choice of not having to be in traffic if they don't have to be.

Mathieu: Lastly, Secretary, I'll go back to the point of frustration that you mentioned: people who have to take the T to work. Can you tell them where we are in the ballgame? Is that even possible? There's a long-term goal, I'm assuming, to make the T perfect. You're working on the Orange, you're moving to the Red [and] you're doing the Green. Where are we in this ballgame? Is this a decades-long effort?

Pollack: We're in year four of a 15-year effort to cut to completely transform the T and rebuild it. And not just fix the things that are broken, but make it a better system and a system that can carry more people. So Red and Orange lines, every single contract is under way. By the end of 2023, we'll have 100,000 extra seats with new cars, new signals, power and track that allow them to provide more frequent service. That's where we started. We're working on the buses next. Green Line will come after that. But we're not waiting until the end of the 15 years. So there won't be new Green Line cars for a while, but we can be out there every weekend fixing the signals and tracks, lifting those speed restrictions, making the system work more reliably even in the short-term, while we wait for the big investments in things like new cars.