08 February 2007

Retail and Transit

OK, I have from time-to-time linked to Richard Layman’s blog “Rebuilding Place in the Urban Space,” and he has two great posts today. Richard, keep up the good work.

The first post deals with some thumbrules of retail and the US Patent and Trade Office (sound familiar, Columbians?). It is certainly a great read and provides some perspective.

The second post deals with transit ridership and is a great compliment to Hayduke’s post today.


Anonymous said...

Richard's got a lot of interesting ideas, but some don't hold water. See his comment on Evan's Metro post as well as the comment responding to it.

Richard Layman said...

So, you're saying that PRT makes sense? Speaking of making sense, the whole point of light - heavy rail is having lots of people move in a set of linked vehicles. Tradidtional light to heavy rail can move 15,000 to 60,000 people per hour. How many people can PRT move in one lane mile/hour? That's why PRT makes no sense, at least to me.

I never saw the other comment. But the thing that screws up WMATA throughput is that it is built to support polycentrism not centrism. Check out the argument in Steve Belmont's _Cities in Full_.

The real issue is properly linking land use and transportation planning. WMATA does exactly what theorists like me say it should be doing, in Arlington and DC--and even there, the density of stations is miniscule compared to Paris.

Stretching out the system (such as beyond Greenbelt) isn't about transit efficiency but enabling development.

That being said, I agree with providing more transit options beyond the Greenbelt station, but recognize (see Belmont!) that it is to achieve objectives other than efficiency.

Generally, when people use broad general statistics, I find them to not be relevant when considering areas where transit and density is more in concert. I write about areas where transit works, not where it's satisficed.

Don't think that we don't screw this up in DC all the time. We do, see: http://urbanplacesandspaces.blogspot.com/search?q=takoma+testimony

But if you want to use statistics, 40% of all transit trips happen in Chicago and NYC.

Why do you think that is?

Because the transit system developed around density, and it is still efficient to get around by transit as a result. Plus, of all U.S. central cities, those two are the most healthy (maybe Boston is third, but it is much smaller).

Anonymous said...

Yes, I'm saying PRT makes sense. It would cost less to build, cost less to operate, use less energy, get more people to where they are going faster, would enjoy higher ridership than light- or heavy-rail, and would decrease use of fossil-fuel burning, smog-generating transportation modes.

You saying the whole point of light-heavy people having lots of people moving in a set of linked cars requires just about all of them to wait unnecessarily. For many outside of urban areas, it's extra time to drive and park and walk to the station, wait for the next train to arrive, wait to decelerate/stop/wait/reaccelerate at each intermediate station, possibly also disembark to change lines and repeat the process to get to one's destination. The more convenient a big-slug train line is made to pedestrian access to more neighborhoods (by adding more stations), the more waiting is built into the rides due to more intermediate stops. So, only a small percentage of those with the option of auto vs. Metro choose Metro.

PRT, using offline stations and more densely-situated stations, would allow far more people to walk to a station, embark immediately (because offline PRT stations allow PRT vehicles to loiter awaiting passengers), and proceed non-stop (unlike light- and heavy-rail) to their specific chosen destination. PRT's station density could come much closer to approaching Paris' station density than light- or heavy-rail every will here.

How many people can PRT move in one lane mile/hour? About 14,400 per each lane mile/hour if single occupancy, 28,800 if double occupancy. PRT, both having narrower vehicles and riding on elevated guideways, could use either dual guideways or stacked guideways to achieve equivalent or greater than maximum throughput rates of light- and heavy-rail. And with those additional guideways, PRT would still cost less to construct than light- or heavy-rail lines.

Just one acceleration and just one deceleration. That means less energy necessary, too. And small, self-guiding PRT vehicles can be operated around the clock, since it doesn't require many passengers to offset the cost of moving a tens of ton light- or heavy-rail train and it doesn't require a driver. Third shift workers deserve transit, too, don't they?

I don't disagree with Steve Belmont's premise that fixing cities should take priority over facilitating suburban development in the pecking order of smart growth initiatives. Nor do I disagree that stretching WMATA, or any mass transit infrastructure, beyond urban areas will enable outlying development. But to use accessibility of modern mass transit as a means to control sprawl is the wrong solution - planning, policy, and zoning are the correct tools to use. Should outlying residents really be forced to continue to use vehicles that only really use 1% of their energy to move the driver? Frying the planet to promote urban renaissance isn't the way.

Transit can work in more areas, specifically lower density areas, if transit systems with lower costs like PRT are used. And I'm not saying that from a "let's facilitate sprawl" standpoint - it's to reduce energy consumption, emissions of greenhouse gases, commute times, and costs of transit for all who use it.

Richard Layman said...


Richard Layman said...

Plus, I don't really care about transit in low dense outer suburbs. People should live in center cities...