The usual argument goes something like, transit ridership is up! If we just add more buses and build more light rail, we'll be able to solve our transportation problem.
In particular, the hackles tend to go up over cost -- PRT is expensive, so it will take resources away from transit. As though PRT would not be transit.
Next year will be my 20th since first learning about PRT. My motivation for supporting it then, as now, remains the same: The transportation problem is too big to continue relying solely on traditional, conventional transit technologies. The magnitude of the problem calls for real innovation, not tinkering around the edges.
A look at what is currently considered transit 'success' actually serves to give the problem its proper context.
Recently the Puget Sound region's leading transit agencies announced ridership was significantly up in 2007. Metro (King County) reported a 7% increase, while Sound Transit (a commuter-oriented agency serving parts of three counties) reported a 12.5% increase.1 The Washington Public Interest Research Group, a fundraising and policy advocacy group, released impressive statistics on how transit usage translates to fuel saved, fuel costs saved, and tons of CO2 not emitted.2
But can annual marginal increases in transit usage get to the kind of ridership we need to reduce numbers of car trips, car miles traveled, and emissions? Interestingly, the recent trumpeting of transit gains made no mention of two important, context-providing numbers: total daily motorized travel, and transit's share of that travel (called transit "mode share," or "mode split").
Oddly, these numbers are not aggregated in one location, despite transportation having been a major preoccupation of the Puget Sound region for years. However, I have what might be called glacial patience, and I have rounded up data from a number of agencies.
Annual transit ridership for 2007
These numbers are mostly available from transit agencies or news sources.
| Agency | Annual riders | Notes |
|---|---|---|
| Sound Transit | 13,500,000 | based on 1.5 million being a 12.5% increase |
| Metro Transit | 110,000,0003 | |
| Community Transit (Snohomish County) | 10,400,000 | Based on a midyear report that ridership was trending 5.4% higher than 9.9 million trips in 2006.4 |
| Pierce Transit | 16,900,0005 | |
| Skagit Transit | 450,000 | |
| Intercity Transit (Olympia) | 4,300,000 | |
| Kitsap Transit | 4,000,000 | I had to estimate this as one-third of Sound Transit's ridership. The only good data on KT is that they serve 15,000 per weekday, a little more than a third of Sound Transit's 44,000 per weekday.6 |
| TOTAL | 158,050,000 | This is about 433,000 a day on average |
Annual total trips
For all modes (cars, trucks, transit, etc.) this is about 10 million a day, or 3.7 billion per year.7 I've also read recent claims of 12 million a day, growing to 16 million a day by 2030, but I'll be statistically conservative and keep it at 10.
The size of the problem
Transit's annual mode split in the region is therefore about 4.3%.8 The percentage would of course be lower if a higher number is used for total trips .
It is useful to keep two other things in mind. 1) The length of the average person's "journey to work" varies 10-14 miles depending on household income.9 2) Washington's new law on climate change, recently signed by Governor Gregoire, includes goals to reduce annual vehicle miles traveled 18% by 2020, 30% by 2035, and 50% by 2050. The starting point is 75 billion annual miles, so you can do the math.
These numbers impart a sense of scale. How do you impact that many people, traveling that many times, for that many miles?
In short, 12.5% annual increases are hardly going to make a dent in the problem. Even if we were able to increase daily transit ridership to 1 million (a 230% increase) with more trains and buses, that is a transit mode split of only 9.9%.
Why not innovate?
No one is saying transit is going to do it alone. There is going to be travel demand management (e.g. tolls, congestion pricing), as well as individual lifestyle changes. But the latter is an aggregate of the millions (probably billions) of microeconomic decisions each of us makes about housing, work, shopping, school, recreation, etc. Those are millions/billions of things that have to go mostly right in order to make this dream called Sustainability come true. There are going to be a lot of innovations along the way.
In the face of these challenges, WHY NOT innovate transit too? Current versions of Personal Rapid Transit, an automated peoplemover concept that combines the speed of a train with the flexibility of a bus, convenience of a taxi, and greenness of an electric car, have been researched in Europe during the past decade.10 PRT is basically the 'horizontal elevator' idea you might have heard about in years past.
Potential niches include getting people quickly to and from train stations without driving, circulation transit, and rapid transit service to districts where large footprint rail technology can't fit or isn't economically justified.
The first one is being built now at Heathrow Airport; physical tests have demonstrated greater capacity than any light rail system operating in the UK.11 We should be telling our transit agencies to start planning PRT networks now.
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1. Pulkkinen, L., "Sound Transit ridership rose 12.5% in 2007." Seattle P-I, Mar. 10, 2008
2. Lange, L., "Transit benefits: new study, new campaign." Seattle P-I, Mar. 6, 2008
3. Lindblom, M. and Gilmore, S., "Riders pack buses in record numbers." Seattle Times, Jan. 24, 2008
4. Community Transit, "Community Transit News." June 28, 2007
5. Austin, A., "Ridership up regionally, a tipping point for transit?" Morning News Tribune, Jan. 31, 2008
6. Sound Transit, "Dump the Pump Day June 21." June 12, 2007
7. Sound Transit, "2005 RTPO Plan Review." April 2005
8. 158,050,000 ÷ 3.7 bil
9. Puget Sound Regional Council, "Regional View Newsletter." Dec. 2007
10. Ironically, based on groundbreaking work done by the old Urban Mass Transit Administration in the 1970s
11. Virginia Dept. of Rail and Public Transportation, House Document 11: "Viability of PRT in Virginia." Jan. 11, 2008, Sec. IV(C)
3 comments:
Excellent analysis of the situation. I very much agree. Here's my own PRT concept...
www.prtproject.com
I would love your feedback...
gary
Hi Gary, we've exchanged correspondence before.
While I understand you want to beef up the control system in order to save money on elevating the system, writing the software to create the kind of collision avoidance you'll need is a huge task. People I know who understand how it would be done say it won't be anywhere near cheap or easy.
In addition, you're going to have to embed the rails, or bicyclists including me would have a big, politically powerful problem with it.
Since you want to stay on the ground as well as develop such an advanced control system, why not ditch the rails and develop an automated, shared-user road vehicle?
As a computer programmer for many years, I don't see the control system as that difficult. The hard part will be tuning the sensors, accounting for inclement weather, etc.
As for embedding the rails, too costly and less safe from ground obstacles. I would rather provide strategically placed embedded sections as needed - basically crossings. This may help the control system as well.
Even going into distant future I see non-rail transportation as MUCH more problematic, far less reliable, and far less efficient. That's why I don't see free roaming rubber tires as the best PRT system. Besides...99.99 percentage of all travel is along the same paths anyways, which is why road maintenance is such a costly headache.
gary
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