High-density development and transit: Bad for the environment

From Richard Hall's Planning for Reality:

Transit achieves the highest passenger miles per gallon figures and lowest emissions figures when trains and buses are at full capacity. Typically transit already serves the highest demand arterial routes such as east coast commuter trains serving major employment centers in New York City and Boston. Adding transit to less used corridors in suburban areas (e.g. Marin), or adding life-line buses that are not filled to near capacity serves to reduce passenger miles per gallon and increase emissions.

This means we should not become over-fixated on transit as a means of fighting climate change. We need to look beyond the term “sustainability” and conduct accurate and realistic assessments...

High Density Housing Near Transit Can Increase Delays and Emissions

Such new planning standards that disregard how new development can increase traffic congestion can be highly counter-productive. Instead of driving efforts in a way that in suburban areas can be the most effective---facilitating lower emissions by continuing to consider car delays---new high density housing built at traffic choke-points can make congestion far more acute. Cars that are avoidably stopped for longer can needlessly add to emissions---and this planning approach disregards the inconvenienced caused to the majority of travelers. For these reasons very careful consideration must be given to transit-oriented development in suburban areas...

It also means that we need to understand that switching people from cars to transit has only a marginal effect---and this effect is diminishing and becoming the reverse. This means that we should be careful not to undertake programs that are extremely expensive (such as the $92 billion Plan Bay Area) or that make major impositions and result in adverse impact---such as adding high density housing near transit hubs, and disregarding impact on vehicle delays at highway intersections---as advocated by the California Governor’s Office of Planning and Research's proposed new guidelines...