Clemson University to Lead $1.2M Cellulosic Ethanol Project
Integrated SSFR Process Could Make Cellulosic Biobutanol More Competitive with Ethanol

Study Finds That Aggressive Combination of Land Use, Enhanced Transit and Travel Pricing Show a Median 14.5% Reduction in Vehicle Kilometers Traveled for 10 Year Time Horizon

Box plots of combined policy VKT reductions by time horizon. Click to enlarge. Source: Rodier (2008)

A review of modeling literature on land use, transit and auto pricing policies designed to reduce vehicle kilometers traveled (VKT) found that an aggressive combination of land-use, enhanced transit, and pricing policies compared to a business-as-usual scenario can reduce VKT for a ten-year time horizon by a median 14.5%. Over a 40-year time horizon, the median decrease is 24.1%.

In the study, Dr. Caroline Rodier at UC Berkeley’s Transportation Sustainability Research Center reviewed more than 20 modeling studies from California, other states and Europe. The California Air Resources Board references the study in its Proposed Scoping Plan for greenhouse gas reductions. (Earlier post.)

Box plots of single policy VKT reductions by time horizon. Click to enlarge. Source: Rodier (2008)

If recent trends in the growth of travel continue, even the anticipated reduction in greenhouse gas emissions resulting from improved vehicle technology and fuels will be insufficient to meet policy mandates, Rodier notes. Hence, the interest in policy measures to reduce end-user consumption.

Types of single policies evaluated in the models reviewed included transit; land use; cordon pricing; parking pricing; congestion pricing; VKT (vehicle kilometers traveled) pricing; and fuel pricing. Combined policies included land use and transit; combined pricing; pricing and transit; and land use, transit and pricing. Rodier categorized the findings over 10-, 20-, 30- and 40-year time horizons.

Land use and auto pricing policies are widely considered to be effective policies to reduce VKT; however, historically, in California and the US, the adoption and implementation of these policies have been exceedingly difficult for a variety of political and institutional reasons.

—Rodier (2008)

Other findings from the study include:

  • Employee parking pricing may result in approximately a 1% reduction in VKT over the four 10-year time horizons.

  • Pay-as-you-drive insurance policies may produce reductions ranging from 4% to 5% reduction over all time horizons.

  • Moderate cordon pricing schemes are likely to reduce VKT by 2% to 3% over time.

  • Increased transit investment may reduce VKT by 0.1% to 1% during a 10-year time horizon, and in future 10-year increments, this may increase by 1 percentage point at the higher reduction level.

  • Land-use-only scenarios may reduce VKT by up to 2% in the 10-year time horizon, which may increase by approximately 2 to 3 percentage points at the higher reduction level at 10 year increments.

  • Land use and transit scenarios may reduce VKT by 2% to 6% during a 10-year time horizon, and these figures may increase by approximately 2 to 5 percentage points at each future 10-year increments.

  • Combined land use, transit, and pricing policy measures would bring significantly greater reductions both in the shorter and longer term time horizons.

Rodier noted, however, that improved models are needed to provide more accurate results in the current policy-making context.

In general, the results confirm that even improved calibrated travel models are likely to underestimate VKT reductions from land use, transit, and pricing policies. These models simply are not suited for the policy analysis demands in the era of global climate change. For example, when similar transit scenarios were simulated with the improved calibrated travel model and the integrated land use and transport model, the latter produced significantly larger results (6.0% versus 0.3%).

—Rodier (2008)



The study: All well and good I suppose. The real solution: let gas price go up and stay up above $5/gallon. Keep them up with taxes if needed. The rest then happens mostly on its own.

Elitist = actually honest about environmental preservation.

stas peterson

Despite the hyperbole, it is is easy to demonstrate that 19th century era "mass transit", consumes MORE ENERGY than what it purports to save.

A bus or trolley must have 17 paying passengers for every inch of its route, every route, all day, in order to save any energy over a single passenger driving an average passenger car from exactlywhere he started ot exactly where he wants to go.

The wastage comes from deadheading, little route usage over much of the route, and the abysmal mileage of trolleys and buses. The single pasenger car does not aimlessly follow a route but goes only from source to destination, which saves miles traveled, and hence energy as a result.

Only those suburban, rush hour, fully-loaded, park-and-ride services, actually conserve much of anything. The average improvement in mileage has been about 5.1% per year compounded over the past 35 years, as reported here on GCC pages. Not all of which went into mileage improvements, as safety concerns added lots of weight to cars, and performance was increased from the abysmal levels set during the first attempts at emissions controls, and attempting fuel savings.

But those needs have pretty much been met. So virtually all future improvements will show up in mileage increases. That would dwarf this "hair-shirt" proposal. And that is not including any conversion savings due to substituting electric propulsion.


yea just drive a salvage prius and hypermile and maintain the crap out of it. The best you can do for now, since by the time the car truly dies there is better options.

Andrey Levin

What does it matter, Stas?

My 15 year old son use public transportation (buses) to go to school, back, and generally fool around with his friends all week long. For senior citizens public transportation is a bloodline.

Same retards who devastated American suburban railway public transportation now are trying to devastate personal urban car travel (get people out of their cars).

Is it so hard to understand that we need both viable public and personal transportation? Cars, buses, trains, sub- and under- ground?

Will S

Stas, you make assertions without providing peer reviewed references, so we can't validate your claims.

As for the article, note that the authors had little confidence in their model. Lines like Increased transit investment may reduce VKT by 0.1% to 1% during a 10-year time horizon did little to show any realism in their assumptions.

The comments to this entry are closed.