PRT or PBT?

If you read a lot of urbanist blogs, you start noticing that commenters (thanks anyway, Firefox spell-check, but I will not call them commentators) often fall into certain categories.  There are the Philosopher-Trolls, who never miss an opportunity to re-kindle the Eternal Questions of the transportation world (on-street or separated bike facilities?  why does transit cost so much in the USA?).  There are the Trainspotters, who never miss an opportunity to point out the voltage difference between the Siemens A32B77 car and the Bombardier 7B2R6 car.

And then there are the PRTers, who pop up seemingly at random to preach the mystical transcendent qualities of Personal Rapid Transit, which apparently pays you to build it and will leave your teeth sparkling clean.  On a Market Urbanism post about elevated rail, which I guess is a primitive precursor to PRT?, a commenter linked to a summary of a conference held by MnDOT last summer on that maligned form of futurism, PRT.

I think Tom Sorel has done a good job at MnDOT, and he’s probably done more than any other commissioner to advance multi-modal thinking and spur innovation.  But I have to say I was a little disappointed that we’re still studying PRT in Minnesota.  Rep.  Frank Hornstein made the point at the conference, expressing his concern that “PRT has been under discussion since the 1970s, but most plans have been shelved.”  There’s a little more to the story:  not only did PRT fail to justify construction after all that study, but PRT helped kill rail transit:

In 1972 the MTC [Metro Transit Commission, which was later swallowed by the Met Council and the last word dropped] undertook an analysis of the metro area’s transit needs, called the Regional Fixed Guideway Study. The study recommended that UMTA [I’m not sure about this acronym – Urban Mass Transit Administration maybe?] and the state Legislature come up with $1.3 billion to build a 57-mile intermediate capacity rail system. “It was sort of the Twin Cities answer to the BART,” Metropolitan Council transportation director Larry Dallam says, so the council refused to look at MTC’s study and did its own, which concluded that a fixed guideway for buses was the solution to downtown congestion. The LEgislature promptly shelved both recommendations, did nothing for a year, then appropriated $500,000 so that the MTC could study the only form of transport that hadn’t been discussed: small, driverless, electrically powered vehicles called people movers.

Despite the bad blood (or maybe because of it), the summary of last summer’s PRT conference is a good read.  Apparently MnDOT held the conference after getting 21 responses to an RFI (Request For Information, something Carol Molnau would never have done) about PRT, including proposals to build systems in various Twin Cities suburbs and from Winona, which is applying for federal money to build a “PRT lab and partnership center” that would “integrate a test track into current city infrastructure.”

But unfortunately the conferees agreed on a defeatist attitude about transit in the suburbs.  Steve Elkins, a city councilmember from Bloomington led the charge, with the unsupported assertion that transit service “cannot be a faster option for suburban commuters.”  Well, transit is faster, of course, at rush hour on commuter bus rides that have shoulder lanes.  CM Elkins makes clear later that he is actually talking about local routes on the Bloomington Strip, which is currently served by a tangled mess of buses:

The important thing to note about the Bloomington Strip is that it  isn’t more than a half-mile wide in most places, making it actually pretty walkable.  So when Barb Thoman, executive director of Transit for Livable Communities, describes the area as “too hostile and dangerous for people to get from one place to another,” it is true, but only because the cities have built it to be that way.

Last year I had a training in an office park on the Strip, and at lunch I went to find a scenic spot to munch at.  Hailing from this part of town, I knew that Centennial Lakes and its corporate landscaped grandeur wasn’t far, so I set out to hoof on over.  Needless to say, after several speeding turn lane near-misses and a few Amazing Disappearing Sidewalks, I was pretty frustrated.  But the worst was when I was late getting back, after the confusion of too many T intersections and random sidewalk turns led me on an unnecessary detour.  Yet the spot I found wasn’t any further than my normal lunch spot.  All it would take is a little road dieting (this area is loaded with low-volume four-lane streets), a policy of sidewalks for both sides, and some way-finding and it would be a pretty nice place to walk.

The Bloomington Strip, composed of superblock after superblock of low-slung buildings surrounded by empty lawns or parking lots, is actually an excellent testing ground for the Fused Grid.  Here is one I whipped up with almost no thought:

The orange lines are pedestrian or bicycle ways (ideally both), creating a grid system similar in size, if not regularity, to a standard city grid.  With some decent signage (to Progress Drive, for example, or No Through Walk, for another) it would be a fine place to walk.  With some infill of buildings on these vast parking lot fields, it would be a nice place to walk.

Do we really need a network of elevated monorails to take us from exactly where we are to exactly where we want to be?  I don’t think so, not as long as we can still use our old familiar Personal Biped Transit.

6 comments on “PRT or PBT?

  1. Peter Muller says:

    You are absolutely correct – if it is within a mile, I would prefer to walk. The problem comes when distances are further – then I, and 90% of other Americans, prefer to drive because, let’s face it, conventional transit is slow, inconvenient and ususally doesn’t link our dseired origin with our desired destination very well. With congestion increasing at six times the rate of population growth and transportation accounting for 34% of greenhouse gases, driving simply is no longer economically or environmentlly sustainable and we MUST look for an alternative.

    PRT is the only transportation concept I know of that comes close to matching the convenience of a car while also dramatically reducing energy used and emissions. I believe we are therefore obliged to give PRT a very serious look before we throw it out because of historic hiccups. The Masdar PRT system is now in full operation in the UAE. Heathrow passenger trials resulted in 99.6% availability (6 times more reliable than transit level of service A). Yes, these are only small systems, but it takes very little imagination to see how they could supplement and improve the service provided by conventional transit. MnDOT is correct to be keeping an eye on PRT.

    • You may be right that PRT is worthy of study – I admit that my knee-jerk reaction is against it because I’m afraid that if PRT is built it wouldn’t be in place of a highway, it would be in place of a transit line. Maybe you can help me with one piece I’ve never understood – can you explain why PRT guideway is so much less expensive than rail guideway?

      You are wrong if you think conventional transit has to be slow, inconvenient and disconnected – the buses I mentioned on the Bloomington Strip have insane detours but still manage to be competitive with auto travel times on the same streets. The problem is that the initial investment has never been made to make them competitive in terms of convenience and connectedness. If they straightened out the routes they would save some of the cost of increasing frequency and as people catch on that they can quickly grab a connecting bus the ridership will make them cost-effective as well.

  2. Peter Muller says:

    It will be a long time before PRT replaces other modes. Initially it will serve to supplement them and boost their ridership. It will expand the area available for transit-oriented development. It is just another (potentially very good) tool in the transportation planner’s toolbox. It is no more to be feared than a bicycle.

    The reason PRT guideway is so much less expensive is simple; the vehicles weigh so much less. If you park PRT loaded vehicles end to end on a guideway, the guideway load per square foot is about 40lbs. Design loading for a footbridge is over 80lbs. this is because people crowded together weigh more than small vehicles. Column loading on a PRT guideway ends up being about 10% of the loading on other fixed guideway systems. If you build PRT at grade it requires about half the right-of-way width as light rail for about the same capacity. Read my blog on PRT capacity http://www.prtconsulting.com/blog.html

    I didn’t say conventional transit has to be slow, I said it is slow. There is much data to prove this. However, we do occasionally find conventional transit systems that work. Our studies have found that people prefer personal modes such as car, bicycle and PRT over rail-based modes. The modes they like the least are bus-based.

    • Thanks for the info – I looked around your site but for some reason hadn’t thought to look at the blog. You have convinced me that I need to spend more time looking at PRT. I’m still not convinced that MnDOT needs to spend more time looking at PRT – they have a hard enough time keeping up with the modes they are already operating.

      For the record, I prefer to get around via canoe, but so far I’ve had a hard time convincing local governments to build the supportive infrastructure.

  3. mulad says:

    In my mind, bike sharing is a nice analog to PRT — on-demand, station-to-station service — and bike sharing is waaayyy cheaper to implement.

    • I agree with you, Mulad, although a PRTer might say it’s worth spending waaaay more on PRT because you can use it year-round. To which a Bike-share advocate might respond that you can bike year-round. To which the PRTer might say “maybe you can” and the biker says “try me” and fisticuffs ensue.

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