Who Knew? Seattle Leads the Way in Reducing Traffic Congestion

TomTom's taking traffic congestion to the future, aggregating speed data from its in-car navigation systems to pinpoint precisely which cities have the worst traffic congestion. Here's their scientifically-derived 20 most traffic-clogged cities. The results may surprise some.

Seattle most congested in the nation.

http://jalopnik.com/5421244/tomtoms-20-most-tra…

If you're getting the value of 35 wasted hours for Seattle from that figure, then look again. It shows that the current value is more like 42-43 wasted hours.

So how'd we do it? My guess is a combination of not building new roads (new roads = cheap housing in suburbs = more cars = more traffic) and adding bus service. Considering all of the new roads we're building (doubling 520 capacity, widening 405, etc.) and that we're cutting bus service, I'm guessing the next decade won't look as good (assuming peak oil doesn't hit by then, which would change everything).

That value is “per driver.” SOV Drivers, according to the 2008 American Communities Survey, now make up a minority of commuters in Seattle, 49% down from 54% in 1990.

Since 1990, bicycling is up from 1.5% to more than 3.2% (counts rose 16% between 2007 and 2009 – so one could infer growth from the 2008 sample.) Walking is at almost 11% and transit has held it's ground around 16%. Telecommute is around 5%, carpool/vanpool is holding its own at 11%. The rest is in motorcycle and “other”.

More importantly, the University of Minnesota in its Access to Destinations research series (abstract here: http://www.cts.umn.edu/access-study/publication…) suggests that “hours of delay” is a flawed metric. They suggest that mean-time access to destinations, such as a suite of basic necessities, is a more important consideration. As an example, infill brings origins and destinations closer together, making options – such as walking – more realistic from the standpoint of travel time and comfort.

I've driven in DC, NYC, LA, Miami, Chicago and Atlanta during rush hour, and I'll still take Seattle any day of the week. Seattle has far fewer highways than most cities (and more trees), and “rush hour” in Seattle lasts half as long as larger cities (rush hours in larger cities start before 6am). The larger cities also have a well-developed transit system, and they STILL have lousy traffic.

Also, the TomTom numbers are based on % of roads congested with drivers at less than 70% of the speed limit. The amount of asphalt in all the larger cities is incredible. I appreciate that we can still call Seattle the Emerald City.

Apples and oranges. The TTI data, besides covering 1997-2007, rates time per driver, while TomTom's charts are for percentage of arterial roads and highways that are congested.

And it shows what we all know: the arterials that lead to highways are the ones that are congested:
http://cache-01.gawkerassets.com/assets/images/…
TomTom should also “reveal” that it's single-occupant commuters that cause these problems. That's what make the seattle.gov/waytogo programs and transit improvements so important.

Sounder trains also opened in 2000, and ST isn't in as bad of shape as KC Metro, so there's hope for non-520 areas.

The issue is how congested are the roads. Arterials and highways are clearly the most important to measure. TomTom used the same methodology in all the cities they measured. You can apple and orange all you want but the speed one can drive is the real measure of congestion.

Why should TomTom “reveal” the cause of the slowness of the roadways? They are using a technology that TTI doesn't have and I think is superior to TTI's. How exactly does TTI measure?

Is your position that TomTom was trying to make Seattle look bad? I doubt they had an agenda.

“'hours of delay' is a flawed metric” I agree, and this bugged me when I looked at the graphic. If you have a house in the exurbs and drive an hour each day into the city at the speed limit your “hours of delay” are zero. But you still waste two hours of your life every day. “Hours of driving” would be a better metric.

Seattle's population grew by about 100,000 from 1990 to 2009; that alone could reduce time wasted in driving to work. I doubt we have more bus service hours, either, relative to population. I believe there are slight shifts to working at home, carpooling, to transit and biking and overall people have simply adjusted. I don't think it's that our transit, bike or other policies have caused the adjustment. It's more in spite of our lack of transit, etc.

What these charts don't tell you is how fast the people taking transit get to work, and in DC NY etc. it's pretty fast as they have massive, “real,” train systems. So the folks driving in those towns are pretty much choosing to waste their time. In our town you don't have that choice too much, you can take a slow bus, live downtown, have a short drive from W Seattle or a long drive from the burbs. So we look lower on the chart, but it's due to our superior transportation planning or investments…..we simply have 50,000 people more centered in Cap Hill and Fremont and other close in neighborhoods. They're hardly full btw, it's just slightly more. Even the 100,000 pop growth is pretty low, that's only one percent a year, basically, over almost twenty years.

You seriously believe that the 9000 boardings (4500 riders) a day out of the 13,700,000 trips a day (PSRC number for 2006) has had an impact on congestion? Most of those riders would be on buses, in van-pools or carpooling anyway.

BTW fourth quarter boardings were down 11% year over year.

From the 2006-2008 ACS`Fact Sheet – SOV commutes are at 54% –

The link is hugely long – did you get your 49% somewhere else on their site?

http://factfinder.census.gov/servlet/ADPTable?_…

Actually we have been improving our roads pretty constantly for the past while. 167 for example.

We have not really added much bus service but we have improved routes that buses use with things like HOV lanes and better access ramps.

That and light rail, though this probably doesn't account for that.

In other words our current policy of maintaining road capacity, expanding at choke points, and improving transit and non-SOV car travel is working pretty well.

It's fine if TomTom's measurement is superior; I'm just saying the two are different enough to be not measuring the same thing. TTI describes their current and past methodology at http://mobility.tamu.edu/ums/

Yes I do, because the commute trips (which TTI measured) are a much smaller number, and even buses and vanpools use I-5 while Sounder uses rails.

Having spent the week in San Diego, a much larger city than Seattle – I have experienced free flowing traffic almost everywhere…even in popular destinations.

Explanation? Obviously they've built enough highways and made them large enough to handle capacity. Add to that many limited access state routes.

Seattle just hasn't built the needed highways especially East-West limited access highways in the north and south of Puget Sound.

Sounder carries about 1/3 of a percent of the central Puget Sound commutes. Most of the Sounder riders came from buses, van-pools and carpools. The number of vehicles removed from the highways is negligible. Sounder South is much better than Sounder North but neither is having an impact on congestion.

ST own EIS doesn't claim that Sounder reduces congestion.

Wait, how do you know that “TomTom used the same methodology in all the cities they measured?” Looking briefly, I can't find anything of any real substance on the TeleAtlas methodology. And even if they did use the same methodology, how dependent is the analysis on the make-up of the user base, and how does the user base vary from city to city?

Say what you want about the superiority of other technologies, TTI's is transparent:

http://mobility.tamu.edu/ums/

The extra lane on I-405 near Ext 2 has done wonders.

This is the type of project that should have been done decades ago.

Same widening all of I-405.

Same with extending the I-5 Express lanes southward maybe to Tukwila.

There's a huge amount of traffic that doesn't want to go to Seattle–just get around it.

But unlike every other city there are no by-pass routes. Plus they screw it up even more by having ridiculous exits like Mercer and Seneca right in the middle of the I-90 interchange!

This isn't a matter of “sprawl” or all the other Urbist excuses.

I think building an elevated bypass to get completely around Seattle and divert the through traffic would do more than all the “mass transit” in the world.

Seattle is much too dense to ever have effective transportation. The house plots are half of an exurbian size, and the condos have no green space and so are very unenvironmental compared to Issaquah or Kent.

Best strategy would be to buy up all foreclosures and empty commercial buildings and turn them into parkland, then de-densify through zoning to bring Seattle into compliance with the ring of Puget Sound exurbs.

“Say what you want about the superiority of other technologies, TTI's is transparent:”

If it's bad who cares if it's transparent. It would appear that TTI does a car count on freeways and calculates the time delays primarily from that variable. I didn't peruse it, just a scan.

I'm more concerned with city street congestion. I don't think TTI looks at that at all.

You can't possibly be serious

Found this: “TTI's congestion data are not based on actual measurements of congestion in every city. The Institute calculates the travel time index and other congestion costs using formulae that assume that freeways, arterials, and other roads have certain flow capacities. When reported uses approaches or exceeds those capacities, the Institute's formula projects that traffic will slow and travelers will be delayed.”

san diego is a city split in two by a 12+ freeway running down the middle of it.

you didn't drive in places where there is traffic when there's traffic. it would make the transit advocates here puke…

I think he's not comparing apples to apples. When the Census data comes out and shows those shifts I'll believe it.

.3% or 9000 boardings a day is not nothing, and that plus ST buses and now light rail, all the various commute reduction programs, and bike commuting increases all add up to less bad congestion in Seattle. I'm not saying our work is done, but yes even tiny improvements add up.

And it's a whole lot cheaper than whole new freeways like they've built in Dallas.

“Seattle just hasn't built the needed highways especially East-West limited access highways in the north and south of Puget Sound.”

And how would Seattle manage to build highways in north and south Puget Sound? Besides buying up all those foreclosures and empty commercial buildings.

I think Seattle's $50M down, not 5$50B up, and it's a city, not an empire.

Clearly we need more capacity from Everett to Gold Bar, and from Tacoma to Mt. Rainier…