Study on the "green-ness" of public transit

[JimPlans]

I ran across this blog posting at the Monitor:

How green are trains, public transportation, and hybrid cars? It depends.

The blog post references this research paper:

Environmental assessment of passenger transportation should include infrastructure and supply chains

While the results didn't really surprise me (such as the fact that nearly empty buses pollute a lot more per passenger than an SUV and that all environmental impacts of transportation options should be measured, not just operational ones), they did make me ponder the implications of the findings.

To me, the take-away is that public transit systems that don't implement serious TOD planning and zoning changes that allow high density and resulting high levels of use aren't really doing the environment any good. Also, we need to power our buses with something other than diesel engines (or feed those engines biodiesel).

Any other thoughts?

[Tide]

The most interesting part of this article was the mention that fuel-efficient and hybrid cars are actually bad financially for governments who repair roads based on gas taxes, as we do here in America. I think this might help the realization of a mileage tax or congestion pricing in American cities.

[dvdneal]

I like the article, but the research is much more interesting. It gives a good threshold of how many passengers you need to pick up to make it efficient.

My questions has always been, at what point does a hybrid vehicle's fuel savings match the construction cost of the new vehicle (speaking in terms of carbon footprint). If I were to spend the money on a hybrid, would it actually be greener than keeping my '96 truck. The truck burns more gas, but the energy cost of construction has already been paid.

[maxxoccupancy]

Heavy trucks do vastly more harm to roads than cars to. I heard about a study where heavy trucks were causing like hundreds of times more wear per vehicle mile traveled, but I don't remember the exact figures.

Hybrid vehilces use up less fuel and pollute less, so I can't see that as a bad thing.

As far as mass transit goes, I remember a statistic from somewhere that Metro busses in King County, Washington, were carrying an average of 2.2 passengers at a time. Because they have to cover more miles per trip, they end up being a terrible deal from every vantage point--pollution, increased congestion, funds taken from road/freeway maintenance, etc.

Unfortunately, the transit unions have so much political power than good transportation policy is difficult to enact. The public sector unions pour over $9 billion a year into Dem campaigns (and some into RINO's and some socialist advocacy groups). I mention this here because they are, IMO, the biggest obstacle to good transportation policies.

[Gotta Speakup]

Of course an empty bus is going to use more energy and be less efficient than a car. But the savings at peak times are quite overwhelming. It would be interesting to see if the benefits of peak travel for transit outweigh the inefficiencies at non-peak times.

Also, the article does not take into account the other problems with cars: land consumption. It only uses the infrastructure cost of building parking (mostly just paving over land) but the other environmental impacts. This would have an energy cost as well.

[Wolfman]

Also, we need to power our buses with something other than diesel engines (or feed those engines biodiesel).

Actually, thats a bad idea. Vechicles running Biodeisel tend to have more mechanical problems in the pump and injectors. Biodeisel holds together more (it has a higher viscosity). The best way to explain this is with oil. If you put a 30W50 oil in an engine needing 10W40, you're not gonna do very well. The oil is too resistant to flow, as is Biodiesel compared to diesel. However, there are companys that make vechicles specialised for biodeisel. The same principle holds for putting Ethanol in a gas engine. You can, but you're gonna **** up your engine.

It's sad that the major thing I have to talk about isn't even on topic.

[delawaresooner]

I'm skeptical about the validity of the argument. For instance, I've read articles which argue that hybrids are worse than SUVs because they a) don't last as long 100k miles v 300k miles, and b) the mining of the materials for their batteries creates more pollution than building an SUV.

Of course, such articles are written to imply that driving an SUV is just fine. The writers do not argue that people should ditch SUVs and Hybrids, and drive smart cars or mopeds or (gasp!) walk.

The point made earlier that good public transit goes hand in hand with good TOD and urban planning is, IMO a no-brainer. But the public only sees empty buses, without looking at the lack of side walks, density, narrower streets... etc...

[wahday]

Sorry for the duplicate posting. Can a moderator help me delete this one? I can't seem to figure it out....

[wahday]

Well, now I have my skeptic hat on as well. One thing I did not see in the study is the estimated cost (monetary and carbon output) of, say, road maintenance compared to rail maintenance over time. Maybe they considered that,but I don't have time to look at the original study.

It also seems to me that these figures are based on current ridership levels. One question I would have is: how many passengers/unit of time do trains or buses need to have to become more efficient than auto transport? I was surprised, for example, that planes were considered to contribute less when they are huge fuel users. One explanation is that planes are almost always full to capacity, whereas train or bus ridership in many cities (especially when considering peak and off-peak times) may be way below capacity. If the buses were packed, what impact would that have?

Also, I would assume not all trains are created equal. How does the carbon output (including all life cycle considerations) of a diesel Amtrak train compare with light electric rail, for example?

Personally, I thought the study was interesting for its insistence on considering the entire carbon impact of different transportation modes. I think, though, that what it shows is that more understanding is needed on what would makes different modes more or less impactful in terms of global warming contributions. The ultimate goal, afterall, is not to maintain our current output (which continuing to drive our SUVs would accomplish), but rather REDUCE it. So, how do we achieve that? Not easy, obviously, but saying that commuting by pickup is no less harmful than by train doesn't help us reduce anything. It does, however, make us question if we aren't actually increasing it.

Lastly, MaxxOccupancy said

As far as mass transit goes, I remember a statistic from somewhere that Metro busses in King County, Washington, were carrying an average of 2.2 passengers at a time. Because they have to cover more miles per trip, they end up being a terrible deal from every vantage point--pollution, increased congestion, funds taken from road/freeway maintenance, etc.

I don't know where they were drawing these figures from (maybe specific routes) or when, but I have ridden buses in Seattle many times and, at least from my personal experiences, they are very heavily used. I was up there for a conference a few months ago and of the four times I rode (granted, roughly in line with rush hour) it was standing room only on an articulated bus. I was kind of blown away. In fact, I had to pass one bus up as it was too packed to accept more passengers.

As a side note, I felt so terribly out of place on the bus in Seattle. It seemed everyone had some sort of digital gadget (they have wifi on the buses there) they were busy manipulating while sipping coffees and looking fashionable. Laptops, iPhones, Blackberries, and on and on. I had a cell phone that doesn't even fold and a 10 year old rain parka. I half expected people to toss me some change out of compassion.