Driving is the problem, not the solution

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10-110 interchange

The 10/110 interchange in LA (courtesy of National Geographic).

We’re officially in the middle of the holiday season, which can only mean one thing – that’s right, the 5-year American Community Survey (ACS) data for 2016 came out last week. I can only assume that everyone else also leaves out their blank spreadsheets overnight, in hopes that the Census Bureau stops by your house.

I spent much of last Thursday drilling down into the data for Northeast Ohio, starting with one of my favorites – Means of Transportation to Work, which breaks down commuting habits.

Driving alone is not getting less popular

Initially, while crunching the numbers, I found something unexpected – it appeared that the single-occupant vehicle (SOV) rate in the region had actually fallen to 81.5% from 2012-2016 from 82.1% from 2007-2011.

Of course, because this is Cleveland, my hopes were soon dashed. I realized that I had made a mistake, and when I redid the numbers, the results were depressingly predictable; the SOV rate had actually increased ever so slightly to 82.097% from 82.096%. Though this increase is barely perceptible – if you hold the number of commuters constant, it translates into an additional 11 people driving alone – it underscores the broader point that, despite all the reporting about Millennials giving up their cars and people moving into the urban core, driving alone remains the overwhelmingly dominant mode of transportation in this region.

Perhaps that number will come down as Baby Boomers continue to age out of the workforce and make way for younger employees. The SOV rate for workers aged 20-24 is just 74.7%, compared to 84.7% for those aged 45-64. But just placing our hopes on demographics to save us is not enough.

We know about the costs of our driving dependence – thousands of people die each year in crashes, thousands more are sickened and/or die from transportation-related air pollution, even more fail to get enough physical activity, and we continue to pump massive amounts of greenhouse gases into the atmosphere.

It’s the driving, stupid

Fortunately, we have begun in earnest to discuss the social, economic, and environmental costs of the autocentric system we’ve built. Yet, most of the work around this issue centers on infrastructure, development patterns, and technology. We note how overbuilt roads induce driving. We discuss the ways in which urban sprawl exacerbates segregation . We note how switching to EVs and autonomous vehicles can reduce emissions and relieve congestion.

Each of these threads is valuable, in and of itself. Nevertheless, these discussions frequently dance around the margins of the central point we frequently try to ignore: we drive too damn much.

Monthly vehicle miles traveled (VMT) reached an all-time high in August at 283.3 billion. The 12-month rolling average also hit a new high in September, when it crossed 3.2 trillion for the first time. This mark is 5.3% higher than the pre-Recession max.

fred 12-month vmt

12-month moving average for VMT (courtesy of the St. Louis Federal Reserve).

Despite the overwhelming ubiquity of driving – or, mayhaps, because of it – we tend to treat this issue as the 800-ton gorilla in the room. Erstwhile advocates for social and environmental issues frequently go quiet when it comes to driving.

If you read through the information that supposedly sustainable organizations include about their events, you’ll notice a common theme: they almost always tell you how to drive and park for free (or cheap), but few give details on how to get there on transit or another mode. Automobility is the assumed status quo, and all other modes are aberrant.

Shifting the focus from the built environment to the transportation mode itself

Accordingly, it’s important for researchers to shift their theoretical lens and focus on the social and environmental impacts not just of development patterns and the built environment, but of our transportation habits themselves.

This is particularly important given the recent trend towards the suburbanization of both poverty and people of color. We know that low-income people who rely on alternative modes want to own a car, by and large. And why shouldn’t they? We crafted a national narrative that the American Dream is a suburban house with two cars in the garage, and then we spent decades systematically denying that dream to people of color. The problem is that what may be economically rational for the individual is harmful for society as a whole.

In a set of recent studies, Chad Frederick and John Hans Gilderbloom from the University of Louisville seek to fill this gap in the literature by focusing directly on driving. Using a dataset of 148 midsized cities, Frederick and Gilderbloom examine how commute mode diversity (CMD) – that is, the share of workers who commute via a non-SOV mode – affects socioeconomic outcomes.

The impacts of driving alone on public health

In the first study, which they co-wrote with William Riggs of Cal Poly, Frederick and Gilderbloom looked at the effect of CMD on public health.

Using ACS data, the researchers sought to demonstrate whether or not modally diverse cities would have better public health outcomes than car-centric cities, even after controlling for key covariates, including latitude, density, population, income, race, and education.

Based on their analysis, auto-dependent metros averaged 15.7% non-SOV mode share, while modally diverse metros had nearly double that share (29.2%). (Nationally, that number is 25.6%, while it’s just 17.9 in Cleveland.)

These modally diverse cities had better access to park space, were more physically active, and were less obese than their peer cities. Compared to auto-dependent metros, modally diverse ones had 5.6% fewer obese people, suffered 1,400 fewer years of life lost per 100,000 people, and had better rates of low birthweight children (7.3% vs. 8.9%).

According to the authors,

This study finds powerful statistical evidence that high modal diversity and a multimodal travel environment to be as important an issue for public health as many other sociological, geographical, and economic concerns, including race, density, latitude, education, and income. Auto-dependency in American cities can have harmful health effects compared to cities with greater transportation choices. People living in modally-diverse cities are more likely to live longer and better; their quality of life is significantly higher, and they enjoy lower rates of obesity. Significantly, more children begin life in a better physical condition when their mothers enjoy a modally-diverse environment.

Does driving alone drive inequality?

In their second study, Frederick and Gilderbloom set out to study the relationship between commuting and income inequality in this same set of cities.

To explore this relationship, they posited three questions:

  • Are multimodal and auto-dependent cities different in regards to income inequality and housing costs?
  • Does CMD have an effect on inequality between black and white workers or between male and female workers?
  • Does CMD affect rental affordability and home values?

These questions are important, as we know that providing poor people with access to a personal car does increase their economic opportunities on a personal level, but car dependence has clear systemic effects.

Frederick and Gilderbloom control for the same variables as their other study, but they set out to look at the effect of mode share on median household income and worker earnings, housing and rental costs, and housing overspending (i.e. spending more than 30% of your income on housing).

In multimodal cities, black workers earn more, homes are worth $58,000 more, and overspending by renters is 5.3% lower. Rent is $174 lower, on average, in auto-dependent cities, but men earn less, which offsets that benefit.

CMD has the second strongest effect on the difference between earnings for men and women (behind only median household income), and it is actually the strongest variable for the difference in earnings among white men and white women. Moreover, CMD is the only independent or control variable that generates a statistically significant reduction in the household income gap between whites and blacks.

The authors find that “African-American men and white women benefit from multimodality, but white men do not lose wages,” which provides strong evidence that “urban life is not a zero-sum game.”

They argue that expanding transportation options among people of color increases the competition among employers for their labor, which drives up their income. Depressingly, the study does not find a benefit of CMD for black women, but Frederick and Gilderbloom argue that this result “speaks to the structural segregation of women from the larger economy, a program that transportation policy alone cannot address.”

Ultimately, these studies clearly indicate that expanding automobility will do nothing to address public health disparities or economic inequality. To resolve this tension, Frederick and Gilderbloom state that,

We need a fundamentally different kind of urban form where the relationship with the automobile is reversed: instead of designing our cities around cars, and merely accommodating people, we should design our cities around people first, and let cars find a niche.

Combined, these studies show the extent to which driving has not only further engrained social inequities, it has widened them. Giving more people more cars, whether autonomous or not, whether electric or not, is not going to bridge the racial wealth gap. If anything, it will only serve to widen it, by burdening low-income people of color with the costs of car ownership.

It’s not enough to set aside some miniscule piece of the pie for other modes or to carve out a few miles of bike lanes from your city’s massively overbuilt road system. We need to recognize that the costs of driving are enormous and choose to fund alternatives first.