University of California Transportation Center

For those concerned about energy use and greenhouse gases in the transport sector, virtually all trends are in the wrong direction -- in the US as well as in most other countries of the world:

•Transit market share continues to drop, now accounting for less than 2% of passenger travel in the US;

•vehicle use and ownership continues to set new records every year, with each licensed driver in the US now owning 1.1 vehicles and driving over 14,000 miles per year on average;

•vehicles are getting larger and heavier every year;

•fuel economy of new vehicles is worsening and is now at its lowest level in the US since the early 1980s;

•GHG emissions from transportation are increasing at 2% per year in the US and at similar or higher rates in virtually all countries with expanding economies;

•transportation accounts for an increasing share of increasing CO2 emissions virtually everywhere (increasing from 16.9% of worldwide total in 1971 to over 20% today).

These trends are disturbing, but not unchangeable. Indeed, the potential for energy saving and greenhouse gas reduction in transportation is huge. The many strategies for doing so may be clustered into three groups:

•reduce vehicle travel;

•improve conventional vehicle technology; and

•introduce advanced technologies and low-carbon fuels.

All three are important. The first, reductions in vehicle travel, are desirable for a variety of reasons, and certainly merit strong support. But in terms of GHG reductions, technology-based strategies (the 2nd and 3rd strategies) are likely to be far more effective, especially in the US and probably in all OECD countries. Very large reductions are possible with improvements in conventional vehicle technology, and even greater reductions are possible with emerging electric-drive technologies and low-carbon fuels.