MARTA TOD blog

MARTA TOD blog

From: Tanya

To: Nathaniel

Thanks for the praise, but it was you and your neighbors that helped the Sierra Club, Georgia Chapter, get MARTA’s 1 cent sales tax passed overwhelmingly in Clayton County this past election. Now comes the fun part—helping the experts design the rail extension and station areas!

From: Nathaniel

To: Tanya

Thanks Tanya! Now that we have it, I am concerned about increasing ridership in the area around Airport/Mountain View Station. That way, we will get more service and can finally sell off one of our cars. You know more about how to do that than I do. Suggestions?

From: Tanya

To: Nathaniel

Sorry to take 3 days to respond, but I wanted to check where MARTA plans to put stations in Clayton. As I recall your area has older industries, including chemical plants,  lots of parking, and other vacant land. It’s a good candidate for substantial redevelopment, especially since it counts as a “brownfield.” There are lots of grants and other programs to help remove toxins from the soil and develop Transit Oriented Development. You’ll hear that called “TOD” more often though. So, just think of Atlanta’s Atlantic Station, but in your area you’re probably only going to get mid-rise buildings. Here’s a picture of a similar project, a BART station near San Jose, California, http://www.sfgate.com/bayarea/place/article/Fremont-s-imaginative-planning-puts-S-F-s-to-5768319.php, illustrated below.

My station, Southlake Mall already has a start on TOD development with a large mall and blocks of parking that could be filled in with housing and local shopping. However, the old rail right-of-way is about three blocks east and may have to be rerouted.  If that doesn’t happen, we need to at least make sure that people can easily bike or walk from there, or even have a bus or streetcar that connects the two!

From: Nathaniel

To: Tanya

That’s an interesting idea, and could work if my neighbors would accept less parking and some mid-rises in exchange for nearby shopping, jobs and other destinations that could be easily walked or cycled to. Just curious, do you know how much fuel and carbon emissions would be saved?

From: Tanya

To: Nathaniel

Bear with me Nathaniel, it’s going to get technical! So, we do have estimates from a Sierra Club transportation activist out in California. To start, he used a study from the transportation consulting firm Nelson\Nygaard titled Crediting Low-Traffic Developments; Adjusting Site-Level Vehicle Trip Generation Using URBEMIS (which can be found at http://www.montgomeryplanning.org/transportation/documents/TripGenerationAnalysisUsingURBEMIS.pdf), especially Table 1, “Summary of Trip Reduction Credits”. He estimated trips and vehicle miles traveled (VMT) for a well-done and complete TOD. Smaller or incomplete TODs would have less reduction in driving and emissions. 

He assumed that:

1. At 30 year buildout, the 80% trip reductions shown in Table 1 of Nelson\Nygaard could be assumed to be the TOD’s driving (VMT or Vehicle Miles Traveled) reductions. This does not take credit for special efforts to reduce driving like building extra worker housing, free transit passes and telecommuting. Nor for the shorter trips TOD neighbors would have in getting to markets and services within the TOD.

2. Initial sprawl (non-TOD) driving equals the GA state average of 31,000 VMT/Household.

3. At 30 year buildout, the TOD covers a 1/2 mile radius from the station (approx 500 acres), with 70% (350 acres) in residences, including residential streets, and 30% (150 acres) in offices, industry, and parks/plazas/open spaces. At buildout, the residential density would be 40 – 60 households per residential acre (hh/res acre); for examples see http://vault.sierraclub.org/sprawl/density/projects.asp?density=3&gm=20&gp=4.10&i=&r=summary.asp . These densities are much lower than San Francisco’s North Beach at 100 hh/res acre, or Manhattan at 200.

4. Auto fuel economy assumed the US on-road fleet averages (real world values for all light-duty vehicles on the road, not inflated CAFE): 21.5 mpg in 2012, up to 37.2 mpg by 2040 (EIA's 2014 Annual Energy Outlook - http://www.eia.gov/forecasts/aeo/pdf/0383(2014).pdf).

5. Burning a gallon of gasoline releases 28 lbs of CO2.

And he got the following:

 

  

So, a well designed TOD would reduce VMT emissions by 4.3 million tons of CO2 during the 30 year buildout, and is then saving 375,000 more tons of CO2 each year. At 10 tons of CO2 emitted annually per car, that is equivalent to taking 430,000 cars off the road for a whole year. In 30 years, we would be keeping 37,000 cars off the road annually thereafter. That’s big-time savings! These driving reductions occur as the TOD is planned, streets laid out, and housing, a market and parks are constructed. This would be followed by more housing and markets, restaurants, plazas and bike lanes, a coffee shop with blazing fast WiFi, a chocolate store, a craft brewery and so on over 30 years.

So in sum, if TOD at your Airport/Mountain View Station was well-done, but had only half as much land in housing and commerce as this TOD example, it would save only half as much driving and emissions, or 2.1 million tons of CO2 during the 30 year buildout, and thereafter 187,000 tons of CO2 annually. Or if only 300 acres of land around the station could be developed, of which 200 acres are residential, the CO2 emission totals would be reduced by 200/350, or 2.5 million tons of CO2 during the 30 year buildout, and thereafter 214,000 tons of CO2 annually. And if my Southlake Mall Station had 150 acres of residential, it could cut emissions by 150/350 of the full TOD example, or 1.8 million tons of CO2 during the 30 year buildout, and thereafter 160,000 tons of CO2 annually.

From: Nathaniel

To: Tanya

Wow! Thanks for that, and boy my head is spinning from all these numbers! But I do understand that most of these driving and emissions cuts would not all be from all travelers riding MARTA to work. Only 15 – 20% of our trips are commutes and TOD can shorten 80 – 85% of other trips enough to walk, cycle or take transit, or just have a shorter drive. Plus, it seems like TOD helps to create great, safe places to be and walk in. Also, TOD will definitely provide many local jobs since it encourages economic activity here in town. It certainly seems worthwhile to pursue this TOD!