Vehicle miles traveled have plummeted across the country with many pre-COVID drivers now working from home (see FHWA’s April 2020 Traffic Volume Trends, released this week). But if social distancing lures many public transit riders into cars, not only will traffic return, it may also be worse than before.

A shift toward more driving of gas vehicles would worsen air quality in cities, thus exacerbating poor respiratory health. Poor respiratory health in turn exacerbates the effects of COVID-19 for those who contract the disease. Across all of these concerns, the outcomes are disproportionately borne by communities of color. Given the potential for adverse public health and social equity outcomes, transportation’s role in contributing to poor air quality should not be overlooked. Before economies begin to reopen in the wake of the pandemic, decision-makers should take action.

Air quality is a public health issue

While vehicle emissions are invisible – and thus at times a difficult issue for policymakers to address – the human health effects are evident. There is a long-established link between motor vehicle pollution and poor health outcomes. The USDOT, Environmental Protection Agency, American Lung Association and CDC are among the many bodies that have linked automobile exhaust to respiratory conditions like asthma, chronic pulmonary disease, chronic bronchitis, decreased lung function, and a weakened immune system, among other issues. We now also know that these conditions and long-term exposure to air pollution increase the risk of death to COVID-19 in the United States.

Air quality is a social equity issue

Automobile-related air pollution is higher near major roadways and highways. In North America, an estimated 30-45 percent of the urban population lives next to a busy road. The numbers may be even greater if proximity to workplaces and schools, as well as the ability of pollution to travel up to 600 feet downwind from the roadway, are accounted for.

Across the country, predominantly nonwhite communities are more likely to be exposed to highway pollution than predominantly white communities due to decades of planning policies and federal infrastructure projects that displaced or built highways through low income communities of color. For example, in Massachusetts, Asian American, African American, and Latinx residents are exposed to anywhere from 26 to 36 percent more vehicle pollution than are white residents, on average. In Southern California, over 1.2 million residents live within 500 feet of a highway, and these residents are disproportionately people of color and have higher rates of poverty. Despite this, air pollution is disproportionately caused by white Americans.

Transportation policy options to address air quality issues

Transportation policymakers and planners should use existing tools in concert to help to address transportation’s role in contributing to poor local air quality. The following three policy areas can be implemented to improve air quality.

Providing quality mode choice options: The Centers for Disease Control and Prevention (CDC), the leading public health agency in the U.S., recently received pushback after initially providing post-pandemic commute guidelines that recommended driving alone. CDC’s initial guidelines were problematic in part because they failed to account for the myriad health harms attributable to automobile pollution. The agency later shifted course to suggest that employers offer incentives “to use forms of transportation that minimize close contact with others”, with biking and walking now first on the list of examples.

Providing options to help commuters avoid single occupancy trips in gas-fueled vehicles is an effective way to reduce commuter tailpipe emissions. Though many commuters may initially fear returning to public transit, the need for shared public transportation will not go away during the pandemic, as public transportation is a lifeline for many essential workers. Likewise public transportation will remain crucial after the pandemic, as city streets simply do not have the space to accommodate personal vehicles for every driver. It will continue to be important for riders to wear masks, and for transit agencies to adopt new cleaning protocols.

There is reason to think that those who can work from home will continue to do so until a vaccine is available for widespread usage, thus keeping workday traffic at historic lows. For offices that do begin to open up, employers may consider staggered work schedules to reduce peak period commutes. In the meantime, public officials can make it easier for people to move around using active transportation.

Developing cleaner cars: The Trump administration’s recent rollback of vehicle fuel economy and emissions standards stands in the way of efforts to reduce not only greenhouse gas emissions, but also local air pollution. As written, the rule would lower the stringency of corporate average fuel economy and carbon dioxide emissions standards to increases of 1.5 percent each year, down from the previous rule’s five percent. The rule could result in 32,000 cumulative premature deaths by 2050.

Incentivizing electric vehicles through tax credits and investments in charging infrastructure are also important means to achieving cleaner vehicle fleets, but future measures should emphasize vehicle affordability. (Note: while the emphasis of this article is largely targeted toward light duty (i.e. passenger) vehicles, heavy-duty vehicles, which contribute disproportionate emissions for their relative fleet size compared to light-duty vehicles, can also benefit from electrification.)

Disincentivize personal vehicle use: With limited roadway space, several U.S. cities are exploring significant changes in pricing to limit use. For example, when done effectively, congestion pricing has been proven to reduce traffic. While Americans are accustomed to paying peak prices for other goods and services, such as movie tickets or cell phone call minutes, paying more to use a road during times of higher demand is new for many drivers. Congestion pricing is one way to internalize the cost of driving and to encourage drivers to seek other modes, travel at off-peak periods, or find other routes. But such proposals need to be crafted carefully to account for social equity and other public concerns.

A number of policy options exist to address vehicle emissions. As the U.S. continues to grapple with the social consequences of the COVID-19 pandemic, a proactive look at reducing transportation’s contributions to air pollution is warranted by decision-makers.