Pricing mechanisms key to reducing transportation emissions

By Chris McCahill

Cities, counties, and states are setting ambitious emissions reduction goals, requiring them to cut transportation sector emissions, which account for more than a quarter of the national total. Electric vehicles powered by clean energy could make a big difference, but it is unlikely those technologies will be deployed at a fast enough rate. To meet their goals, governments need policies that not only keep vehicle use from rising, but also push it down considerably.

Multimodal transportation options and efficient land use patterns can help pave the way, but a pair of recent studies, including one that SSTI worked on, suggest that new transportation pricing structures are probably necessary for governments to meet their goals. The associated new charges needn’t necessarily increase overall transportation costs but, instead, allocate them in ways that let people make more informed travel decisions. This helps in meeting emissions targets, and also in managing traffic and parking demand.

In a new report commissioned by Elemental Excelerator, SSTI found that transportation and land use policies could reduce total vehicle use in Hawaii by 21 percent below 2045 forecasts and seven percent below the current total. Roughly half of those reductions come from substantial increases in the costs to drive and park.

For a study recently published in Transportation Research Part D, researchers at the University of New Mexico show even larger emissions reductions in Albuquerque—a 40 percent reduction by 2050 from the current level. According to their analysis, mileage-based fees ranging from $0.05 to $0.25 per mile (equivalent to raising gas taxes by $1 to $5 per gallon) play the most important role, followed by a major increase in bicycle use.

The recommendations in both Hawaii and Albuquerque also include major transit investments and shifts toward compact development, but those changes have relatively small emissions impacts on their own. Nonetheless, they are critical for supporting less driving and keeping overall transportation costs low, offsetting any increase in the direct costs of driving and parking. In Northern Virginia, for example, price hikes associated with dynamic tolling along I-66 seem to have boosted transit ridership along the corridor as more people opt out of driving.

Chris McCahill is the Deputy Director at SSTI.