December 2008

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Unity

By serial catowner on December 19, 2008

A budget crisis is a good chance to do some pruning, and one of the best places to cut back would be on plans for superferries and superterminals. Any future spending should be for passenger ferries and passenger terminals, and it’s time for a total rethink of the passenger ferry idea while we’re at it.

Tech types will know that when you plot a curve, say of bacterial growth, it goes out for a while and then it goes up. Where it changes direction is called the ‘shoulder of the curve’, and when you push a boat through water and watch fuel consumption, that point is called ‘unity’, and it happens (in knots) at the square root of the waterline length (in feet) of the boat. The underwater shape of a car ferry is close to ideal.

For about forty years passenger ferries have been of the ‘gee whiz’ variety, and they suffer from traffic peaks that make staffing costly. We need to substitute shuttle services that run continuously sixteen hours a day economically. Unsurprisingly, these boats would look very much like the boats that formerly provided these services.

It’s a darn shame the public has been fed this pablum about “40-knot passenger ferries”. I can assure you that none of these boats ever carried passengers at that speed, and the best way to cut the commute would be to have some buses waiting for the ferry passengers- something Kitsap understands, but KC Metro does not. Be firm, be knowledgeable, and the next time somebody starts talking about fast passenger ferries- just say NO!

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Seattle Streetcar is Free Until After Xmas

By Matt the Engineer on December 19, 2008

After the bus system failed me yesterday, and others at the bus stop told me they’d been waiting an hour with no bus in site, I thought I’d walk home. I realized the streetcar would save me a bit of time on this walk, and hopped on board. But when I went to pay, there was a sign telling me it’s free until Dec. 26. So I thought I’d share the news.

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The Tea Leaves of Cabinet Appointments

By Frank on December 18, 2008

Republican Rep. Ray LaHood is Obama’s choice for Transpo Secretary. Erica Barnett rounds up the reax here.

Take John Ashcroft. When he was nominated for Attorney General back in 2001, the big concern was that he was a hard-right anti-choice guy. But no one remembers Ashcroft’s tenure at the DOJ for his take on abortion. Instead, questions of detainee rights and the limits executive power dominated his term. And to complicate matters further, while Ascroft seemed to be a hard-core Bushie on those issues as well, we learned after he resigned that he actually took a respectable stand against Bush’s efforts to shred the constitution on at least one occasion (the infamous hospital room incident).

Paul O’Neill, Bush’s first Treasury Secretary, was a similar case. His moderate views on tax policy ended up with him getting shown the door because of his disagreements with White House staff.

Point being, a lot of things can happen in a given realm of public policy that’s far outside the domain of the relevant Cabinet Secretary. World events and White House priorities being among them. Why, for example, did Tom Daschle accept the role of HHS Secretary only under the condition that he would also serve as white house advisor on health care? Because he knew that the Oval Office is where the action is.

That’s not to say that cabinet secretaries are irrelevant. They run massive federal agencies, hire dozens of like-minded deputies to serve under them and carry out policy, etc., etc. But you can’t extrapolate from a single nominee’s record in congress to the kind of policies they’ll carry out as head of an agency. It’s not a straight line at all.

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Bonds

By Frank on December 18, 2008

California’s cutting back on transit projects because it can’t sell ‘em. The Port of Seattle’s putting the brakes on their new $417M rental car garage for the same reason.

This seems to be happening everywhere, as banks are having trouble selling bonds to cash-strapped (or liquidity-strapped) large institutions.

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Another Failure For Bus Rapid Transit

By serial catowner on December 18, 2008

ExpressIndia reports that:
“despite the “potential benefits of BRTS”, the Bus Rapid Transit System BRTS has been a failure in the Capital.

The Standing Committee report says that in view of the city’s experience, the Delhi government should “abandon the other five BRT corridors as approved earlier”. Instead, the government should strengthen the Delhi Metro rail service with a strong feeder bus network, covering all bus networks in the city, the expert panel suggests.”

At least the Bus Rapid Transit experiments are proving that rail is a good investment.

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KC Metro Brain Teaser

By bgtothen on December 17, 2008

Via Brian over at onebusaway.org

Consider Route #2:

http://metro.kingcounty.gov/tops/bus/schedules/s002_2_.html

There is a route leaving from Downtown to Madrona Park at 1:28 am on Saturday nights / sunday morning. So on Nov 02, 2008 we all fell back an hour. So at 2 am, it magically became 1 am again. So the question is: is there a second trip at the second 1:30 am on that day?

Even better, Route #174: (always my favorite)

http://metro.kingcounty.gov/tops/bus/schedules/s174_1_.html

On Saturday night / Sunday morning, there is a 174 that leaves from downtown at 2:15am. But on when you spring forward in March, there is no 2:15 am (time jumps from 2 am to 3am). So does this route even run?

Something to ponder.

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Some Basics: Mode Choice

By bgtothen on December 16, 2008

Ever wonder how mode choice is modeled? If yes read on…

Mode choices models came to the transportation field via psychology. These models were created to account for the competing forces populations take into account when deciding between a set of options. The model essentially attempt to re-create how people weight the costs and benefits of each mode.

I would first like to walk you through utility equations for each of the modes. When mode choice models are trying to determine how a population will travel it computes the possible utility values for each mode and then compares them to each other. The larger the number (i.e. less negative) the higher the utility and the more desirable it is.

U = utility
TT = travel time

U(sov) = -0.189*TT – 0.0151*cost

The SOV is used as the baseline against which everything else is measured to. From the SOV utility equation you can determine the inferred cost of time. It is very simple and essentially takes into account how long it takes and how much it cost. The travel time includes “terminal time” i.e. getting to your car and then parking and walking to your destination. Cost includes operational cost as well as parking.

U(hov) = -4 -0.189*TT -0.0151*(cost/occupant)

The constant at the beginning of the equation shows that this mode is inherently less desirable than driving alone. The utility of time has not changed and the cost are split between the occupants of the vehicle.

U(bus) = -8 -0.189*TT -0.0151*cost – 0.291*wait -1.427*#transfers

As you can see determining transit utility is much more complicated. The inherent utility of transit is much lower. The utility of time has not changed but the value of waiting is much higher. This essentially says that waiting for the bus for 5 minutes feels like riding the bus for over 7.5 minutes. The last value is the “transfer penalty” which accounts for lower desirability of transferring even if it will be faster. In this circumstance one transfer is equal to about 7.5 minutes.

Next the utility for each mode is raised to the natural log (e^U). These values are summed and then each mode’s utility raised to the natural log is divided by the previous sum. This will give you the mode split probability. The number of trips from one place to another is multiplied by these probability and you’re done!

Below are a few graphs that I made to show what the model predicts will happen with certain changes. I purposefully did not show numbers because they are not calibrated and I only wanted to show the trends. Scenario 1 has the lowest auto cost and time while Scenario 8 has the highest auto cost and time.

You can see that this models shows that SOV’s are much more sensitive to increases in prices than HOV’s. This makes sense because the utility equation divides the cost of the trip between the number of occupants. You will also notice how it takes a while to before the bus starts increasing. This is because it has such a low inherent utility.

In this graph you can see how increasing travel time for SOV/HOV while keeping transit travel times constant can change mode split. You can see how both SOV and HOV shrink at the same rate because they use the same utility constant for travel time. You can also see how the change is not linear. This is a result of setting a negative number to the natural log.

The last graph is a combination of the first and second graphs.

Coming Next: Delay Calculations

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The Northeast Corridor

By Frank on December 16, 2008

Efforts are underway to solicit bids for a “passenger only” rail line between DC and New York. Amtrak currently shares the rail lines with other companies, including freight and passenger service.

While the idea of a high-speed train is appealing, I think you really have to think hard about the opportunity costs here. At 2h45m, the travel time between DC and NY is already competitive with air if you consider the time to get to and from the airports. Getting it down to 2 hours would be nice, but would it really make the difference?

Maybe smaller upgrades like more sidings, bridges, and longer platforms along the route would allow for more — and longer — Acela trains, since the service is so often sold out. Is that 45 minutes worth $40 billion, when passenger service in the rest of the country is so far behind? That’s an honest question, I don’t know.

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Google Transit

By Frank on December 16, 2008

If you care at all about how the Google Transit sausage is made, you should check out this post about the integration issues with the DC Metro.

I wasn’t aware that Google doesn’t usually pay anything for the data. They ought to… it’s a taxpayer-produced good, and the transit agencies could use the money. Do they pay for the MLS listings they integrate into their real estate search? I’d be surprised if they didn’t.

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Connelly: Don't Trust The Experts… Trust Me!

By Frank on December 16, 2008

Joel Connelly, on why the surface/transit alternative for the viaduct is flawed:

A guy from the state Department of Transportation called in, with ready reassurances. The waterfront lights would be synchronized. Traffic that currently drives the viaduct would “disperse” onto city streets, causing less racket on Western Avenue.

Heard that once before, in West Seattle, at a 34th District Democrats’ meeting. A leader of the People’s Waterfront Coalition leader pooh-poohed predictions of congestion on Interstate 5, and forecast that 25 percent less traffic would travel the path of a torn-down viaduct.

No evidence was given. The DOT guy who called in Friday based his prediction on “models” that the department had studied.

The truth is: You can’t forecast the future.

Next week: why global warming and evolution are just “theories.”

We certainly can forecast the future. We can’t always predict it, of course. But that hardly proves anything. Infrastructure projects are usually built based on the best evidence we have at the time. (If we knew in 1953 that Redmond, WA was going to explode into a huge job center, we might have added a lane or two to 520!) Right now the overwhelming evidence says that congestion is elastic. You build it, they will come. You don’t build it, they’ll find another way around.

Why did traffic volumes on I-5 drop so significantly last August during the construction? People carpooled or took transit. They found a way. Some of them liked it so much, they kept doing it long after I-5 reopened.

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