Wednesday, May 23, 2007

Transit System Expansion: Are We Kidding Ourselves?

Here's a link to a recent study by the Reason Foundation entitled "Density in Atlanta: Implications for Traffic and Transit." The study looks at how Atlanta has developed and addresses the question whether the city be able to support a robust transit system in the foreseeable future.

The study found that Atlanta has extremely low population densities relative to other world cities. Like other North American cities, including Chicago, Atlanta's population density is amazingly low. Here are selected population densities on a per hectare basis:

Atlanta: 6
Chicago: 16
San Francisco: 19
Washington D.C.: 21
Los Angeles: 22
New York: 40
London: 62
Paris: 88
Singapore: 107
Beijin: 145
Barcelona: 171
Moscow: 182
Seoul: 322

Assuming a hectare equals .00386 of a square mile, this translates into a population density of 1,554 persons per square mile in Atlanta and 4,145 persons per square mile in Chicago.

The study also found that jobs in the Atlanta area are dispersed and that this dispersal of jobs make the built environment even more hostile to transit.

The study used 7,800 persons per square mile as the minimum density level for a robust transit system. It also stressed that concentrated job centers--e.g., a strong central business district--is key to a strong transit system.

In a somewhat amusing exercise, the authors described what it would take Atlanta to provide its citizens with the same level of transit access as that afforded to people living in Barcelona, a somewhat comparable city in terms of size and role in the global economy--2,100 miles of new rail tracks and 2,800 new rail stations! It then described the kind of Stalinist measures that would be necessary to shrink the physical size of the Atlanta area to generate the population density sufficient to support an expansive transit system.

This region is a bit better off than Atlanta when it comes to a transit-supportive environment, but that isn't saying much. The population density in the Chicago area is still well below the 7,800 per square mile benchmark used in the article. We do have the benefit of a still strong central business district that is a major transit trip generator.

Nevertheless, this article suggests that expanding the public transit system in much of this region is a futile gesture over the next few decades, as Pace has found to its dismay over the past 25 years. How about this as a program:

1. Focus on providing transit to work service in three major regional employment centers: Chicago CBD; O'Hare-Schaumburg corridor; and I-88 corridor (the last two suggested by a commentator). This primarily means more robust Metra service to those areas plus bus feeder service in the suburban employment areas.

2. Focus resources on improving the quality of transit service in regions where population densities are sufficient to support intensive transit service and where there is the greatest chance of people foregoing cars as their primary mode of transportation. This is primarily but not exclusively in the City of Chicago. The STAR Line likely dies--certainly the stretch from Joliet up to I-90. The DuPage J line likely stays and might mature into a useful connection between the O'Hare and I-88 employment corridors.

3. Make the expansion of transit service in all other areas dependent upon sufficient densities of jobs and employment to make that service viable. Use transit service as a carrot to encourage local governments to support denser development.

My hunch is that this program would so alienate many areas of the collar counties that they would object strenuously to continued financial participation in the RTA system. Thus, the RTA region may have to shrink so that there is a better fit between those areas where transit makes sense and those areas where it does not.

2 comments:

Anonymous said...

The Reason Foundation Study you cite is not very compelling because their methodology is very crude. Aggregated average density for a given geography tells you nothing. For instance if all of the regions's population was in McHenry County, Chicago's population density would still be 16 under their methodology but McHenry County itself would have densities seen only on the Indian sub-continent. See the problem with Aggregated Averages? Decision models need to be much more refined.

In fact the region has substantial job densities at the 3 known regional centers. So if a system were built that replicated the existing suburbs to downtown (the many to 1 radial system) at the other 2 centers (Oak Brook and Schaumburg) and the 3 to each other, you would then have a connecting net of "many to quite a few", "many to 3", "3 to 3". See? What does that guy say "Biggest No-Brainer in the history of..." At any rate, existing ridership would nearly quintuple. The new connections required would be a new transverse south-east to north west diagonal approximately, the high capacity rail or BRT version of I294. All this requires a very rare substance for NE IL--leadership. Oh well, wanna get people out of their cars? Give them a feasible alternative. You know the answer by now-- not more money for transit, rather, more transit for money.

db said...

If we ran transit as inefficiently as many parts of Europe, we would need 7,800 per square mile.

Judging by Metra's reasonable farebox recovery rate despite its giveaway fares, double-decker trains that carry 1,000 passengers a pop kind of change that equation, don't you think?

And while I agree that our density is troublingly low in outer suburban areas, the city has to be right around 12,000 a square mile or so -- more if you allow that a sizeable chunk of the city is taken up by the airports and Lake Calumet. Transit failings in the city and the inner burbs are a lack of political will, not economics.

As for the burbs, let's look at a general loosening of zoning, including making it illegal to set a minimum lot size when drafting zoning regulations. That should solve a lot of the sprawl.

Ideally we would have only two zoning rules; agriculture/green space-only, and "anything." The only legitimate zoning interest in my view is preventing irreversible change (such as concreting over the land) in cases where ncessary.