So Sound Transit 3, I think, is a once in a generation opportunity to complete a 116-mile light rail system that will connect West Seattle, Ballard, South Lake Union, up to Everett, Redmond, Kirkland, Issaquah, Federal Way and Tacoma. And you know, what we know is that the region is growing and we grew by 83,000 people last year. We're expected to grow another 800,000 in the next 25 odd years. Traffic is terrible. You just have to look out your window to know that. And unless we find a way to create additional capacity to move people we are going to have challenges that are much worse than what we're seeing today.

Here's a partial transcript - with a little fact-checking to help you weigh the truth behind some of their claims.

A lot of claims are floating around in the public relations struggle over the $54 billion Sound Transit 3 proposal that voters will decide Nov. 8. Who's right?

In reality, this high ridership is possible only on the portion of the system linking downtown Seattle and Snohomish County, where two lines share a track and there is a train every three minutes. Riders traveling from Lynnwood, for example, to Seattle will benefit from all that capacity. But even where the trains come that frequently, 16,000 riders may only be achieved by filling four car trains with 200 people per car. As there are only 74 seats in each car, most people will be standing. Source: Sound Transit's Geoff Patrick.

Claim by "Yes on ST3": A light rail line can move about 16,000 people an hour in each direction.

So I will argue that creating more options that people can get out of traffic will give us as a region an opportunity to continue to stay competitive.

So Transit 3 is an opportunity to create that new capacity. A single light rail train has the capacity to move about 16,000 people an hour in each direction. Now compare that with a general purpose freeway lane that's about 2,000 cars. And what we know is we don't have any more room to build a freeway systems.

The St. Louis Federal Reserve Bank looked into that question as part of its mission to promote sound economic policies across the nation. It found traffic congestion generally increases in growing cities, regardless of whether they have light rail. One reason may be the number of registered vehicles, which continues to increase as populations grow.

This does nothing for traffic congestion. It's the same promise that was made in '96, which I supported in 1996. Same promise in 2008. The implication that this is going to help people with traffic or get you out of traffic is patently false. It has no effect on traffic.

CLAIM BY “NO ON ST3": Light rail was never meant to go to the suburbs.

And light rail was never meant to go out into the suburbs, it was meant for very high dense urban cores. I've got the numbers from Sound Transit. They finally told us how many new riders (and actually they didn't tell us new riders, they told us new trips by new riders) ... So if you can imagine between now and 2040, according to Puget Sound Regional Council, which is the planning agency, we're going to be taking about four million more trips in this region a day. It'll be up to 19 million trips a day just in this four-county region. Sound Transit, even with 100 miles plus of light rail will only attract about 64,000 new trips. That's after decades and decades and billions and billions of dollars. Mostly it's people moved from the buses onto the trains and there's no plan to help those people that are in buses stuck in traffic.

The plan for the last 20 years and the next 30 to 40 is we move people off of buses on to rail.

Sound Transit says reducing congestion is not a realistic goal. Instead, its focus is on moving more people.

Those numbers are cherry-picking the facts. Right now into downtown Seattle - the central business district - 45 percent of commuters are on transit. That's today. When you link open to Capitol Hill and to the Husky Stadium, boardings grew by 28,000. 15,000 of those 28,000 were new trips, new boardings. These were people who hadn't been on transit before.

While light rail may see the greatest mobility improvements when it runs through densely populated areas, the federal government gives other factors, such as the potential for economic development, equal weight when deciding which projects to fund. In recent years, the feds have funded suburban light rail extensions around Dallas; Portland, Oregon; Phoenix; Los Angeles; Minneapolis; and Durham, North Carolina.

Yeah, because Mr. [Dow] Constantine, [King County Executive], who's in charge of Metro and of Sound Transit rerouted dozens of bus routes to feed the train. That's the plan, that's always been the plan, and that's the plan in the future: is existing bus riders. Yet you have high ridership when there's games, but those aren't commuters.

Sound Transit had promised about 103,000 riders by now with that segment. And they're getting all excited because they're doing that once or twice. But it was supposed to be an average by now.

CLAIM BY "YES ON ST3": Many light rail riders are new to transit.

CLAIM BY "NO ON ST3": Most light rail riders are bus riders. The system is not getting people out of their cars.

ANALYSIS:

Sound Transit estimates about 9 percent of trips taken on ST3 systems will be taken by "new riders." But the Federal Transit Authority no longer uses that measure to evaluate the viability of systems. A Federal Transit Authority analysis of the Seattle area’s past light rail projects found that about a third of light rail riders were new to transit. The study also found that compared to buses, Seattle-area light rail attracted riders from “households with significantly higher incomes and marginally higher auto-ownership,” even though the line the FTA studied (between downtown and Seatac) passed through some of Seattle’s most economically stressed neighborhoods.

It is not surprising that some light rail riders are former bus riders, since light rail replaced some of the bus routes that formerly served downtown Seattle.

Yes on ST3’s Shefali Ranganathan:

Some of those transit riders are bus riders. But what is not part of this current conversation is the fact that bus service got better. More neighborhoods are connected with more frequent bus service, better service. And that's the plan for transit agencies all across the region. I mean, light rail opens to Lynnwood community transit... absolutely plans up in Snohomish County to be able to do East West that you can feed into light rail. I talked about capacity of light rail. It is efficient to move those people and people are voting with their feet. A hundred and one thousand boardings a few weeks ago, and yes some of them were Husky game goers but let's be real. What people are making is they're making a choice not to be stuck in traffic so that's why they're getting on the rail because it's four minutes to downtown, eight minutes from Husky Stadium to downtown.

No on ST3’s Maggie Fimia:

Again this does nothing for traffic and they admit that.

So if people think that this investment is going to be reducing traffic just like we thought last 20 years, it's incorrect.

Let me just say also we get calls and letters from folks who have lost their bus service or has been rerouted so that they can't make those connections easily. Older people disabled people. It's fine if you're a young person with a backpack, it might work really well for you. But a lot of people are losing their service.

The whole system needs to rise, not just winners and losers. And that's what's happening in the region.

CLAIM BY “NO ON ST3": People have lost bus service following the development of light rail.

ANALYSIS: Technically true.

After light rail, Metro was able to eliminate some lines that duplicated rail service. Those savings allowed the transit agency to extend bus lines further into neighborhoods – to feed people to light rail stations.

Metro asked the public – would you rather we send buses closer to your house, but infrequently … or would you rather we focus on frequent service to major bus lines – which might require you to walk farther to a stop?

The public asked for frequent service that they might have to walk farther to. When we did reporting on that decision, we found it was older people – and people with physical ailments – who disliked the change.

That reorganization was precipitated by the opening of light rail – but was not caused by light rail. Overall, Metro has more resources to spend on buses because of light rail, but has opted for a more centralized system with more frequent service in response to its users' wishes. Source: KUOW Reports.

KUOW's Bill Radke:

Maggie, what about greenhouse gas emissions reduce because of fewer cars.

No on ST3’s Maggie Fimia:

That is a huge misrepresentation of the facts. They are counting both ST1 and ST2, which brings, I think about 60 miles light rail.

KUOW's Bill Radke:

These are the earlier parts of the Sound Transit plan ...

No on ST3’s Maggie Fimia:

Yes, that we've already approved. They're counting those, plus they're not counting the enormous amount of greenhouse emissions that happen by building these systems. So your net benefit isn't out for decades and decades and decades with greenhouse gas emissions. There's a very good blog on the Washington Policy Center just this week about how it's about $100 we'd pay to get about, I think, 11 cents of reduction.

Yes on ST3’s Shefali Ranganathan:

I mean you're quoting the Washington Policy Center. They are a known conservative blog that I think may be climate change deniers. Look, it is simple. Transportation is the single largest source of greenhouse gas emissions in our region and unless we find ways to give people options to not drive by themselves we are going to be stuck in this cycle for decades to come. And light rail is clean. Electric light rail. And it will move 16,000 ... It has a capacity to move 16,000 people an hour in each direction.

CLAIM BY "YES ON ST3": Light rail is clean.

ANALYSIS: It’s true that mass transit – once it’s up and running – is much cleaner, per rider.

However, KUOW’s John Ryan says it’s also true that Mass Transit Now has exaggerated the potential carbon benefits of ST3 by counting benefits already provided by ST1 and ST2 (whether or not ST3 passes).

Furthermore, Ryan says the more modest carbon-benefit claims made by Sound Transit do not count the greenhouse gases emitted by building light rail.

No on ST3’s Maggie Fimia:

When we decided not to do rail here in the late '60s and early '70s, we turned down heavy rail. And folks need to look up the difference between heavy rail and light rail. What's the difference? Heavy rail is the systems that we... that I grew up with in New York or used in Chicago or BART: Totally separated from traffic. Many, many cars, so can carry thousands of people, and it is fast. Light rail is… can be no more than four cars long and parts of it have to share the right-of-way with cars in intersections.

You can configure a bus system as cities all over the world have done. You get the best aspects of rail ... it's a bus-only lane - pre-pay - bus pulls up all the doors open. People de-board and get on very, very quickly within 11 seconds. So again, like rail … and comfortable seats.

This light rail, when they're at capacity and over capacity, most people will be standing and will not be comfortable and the express bus is going to go away. It's kind of the dirty little secret of this plan. If you're going from Everett to downtown now for work and back on express bus, that's one stop. The light rail has to stop at every station 15 to 16 stops. So when we decided not to do rail, we decided to do a high-capacity bus system here. And we committed to 310 miles of HOV and the bus tunnel and consequently we have some of the highest transit ridership in the country. And we're letting that degrade. Why? Why is that?

CLAIM BY “NO ON ST3": Seattle has some of the highest transit ridership in the country.

ANALYSIS: True.

According to Nate Silver’s fivethirtyeight.com, Seattle had the 12th-highest transit ridership of any US city in 2014.

Yes on ST3’s Shefali Ranganathan:

Look I'm a bus rider. I've been a bus rider for decades and I'm a transit supporter and there is a role for buses and transit three has investments in two bus rapid transit lines on 405 and on 522. There is a role for bus rapid transit. But the vision that Maggie just described requires you doing dedicated right-of-way so that means, picture this: taking away an entire freeway lane for buses not to be stuck in traffic like everything else. She mentioned Everett. The average time that it takes for you to get from Everett to Seattle on time is 76 minutes. That's today. Our HOV lane system is failing and unless we are willing to give up lanes to make this bus rapid transit system work it's not going to work out.

And you know we talked about capacity. To move those 16,000 people that I talked about. You need 175 buses; one light rail train moves that in one direction. And so we're talking about the scale of investment to make bus rapid transit truly shine you will need the scale of investment that you're looking at with rail.

CLAIM BY "YES ON ST3": Our HOV lane system is failing.

ANALYSIS:

Speeds in HOV lanes declined between 18 percent and 38 percent between 2012 and 2014. Theoretically, this decline could be reversed with more restrictive HOV lane entry requirements, a politically difficult proposition given public reaction to lane restrictions recently implemented on I-405.