Spotlight Exclusives

New Index Measures Transportation Insecurity

Alix Gould-Werth and Alexandra Murphy Alix Gould-Werth and Alexandra Murphy, posted on

The role of transportation is crucial  to holding a job, grocery shopping, and getting to school, child care, social services, and other activities. Transportation insecurity — the experience of being unable to move from place to place in a safe or timely manner — has important consequences for people’s ability to connect to opportunity and flourish. University of Michigan researchers have developed the first validated measure of transportation security that offers insights into who experiences transportation insecurity and enables researchers and practitioners to determine which interventions can improve this condition. Spotlight spoke recently with two members of the research team: Alix Gould-Werth, director of Family Economic Security Policy, Washington Center for Equitable Growth; and Alexandra Murphy, assistant professor of Sociology, University of Michigan. The transcript has been lightly edited for length and clarity.

Why don’t you give us some background on how the Index came about?

Alix Gould-Werth: I think the idea came about when I was in graduate school and Alex was a postdoc at the University of Michigan. I remember very clearly listening to Scott Allard give a talk about his book Out of Reach about how social service organizations are often not in close proximity to the people who need most access to them. And I thought back to my work and to what a barrier transportation was to people to get to all the things that they needed. And it occurred to me that if you’re a low-income person or have spent time in a low-income community, it’s very obvious that not being able to access transportation is one of the biggest underlying factors that continues the cycle of poverty.

Yet there wasn’t a lot of information about it in the academic and sociological literature about poverty and inequality, and it occurred to me as I was listening to Scott talk that one of the issues may be that we just don’t measure this well. When it comes to things like food insecurity, we have these standardized measures that are easy to administer and used often, so I thought, what would it look like to have a similar measure for transportation? And so, I started talking to the other Alex about this, who had been doing ethnographic work among people with low incomes in a suburb outside of Pittsburgh. And as we kind of started talking about our experiences with both of our field work and our lived experience, it seemed like this was a tool that was really needed to shine a light on the important role that transportation plays in perpetuating poverty and inequality.

What was the process to actually create the Index?

Alex Murphy: We had a really good model at our fingertips, which is the Food Security Index. And we decided that that was a really good model to follow, not only because it’s sort of the gold standard of measurement around these kinds of insecurity issues, but what is really brilliant about the Food Insecurity Index is that all of its questions are centered around the symptoms of food insecurity as it’s directly experienced by people qualitatively. It asks questions like, in the last 30 days, how often have you had to skip a meal or split a meal because you couldn’t afford to eat more?

That seemed like a really great model because in the transportation world, there are so many different modes that one could possibly take, and it seems impossible to create a question that could catalog all the modes available to you. So, we started with the premise of let’s create a measure that taps into the symptoms of transportation insecurity rather than trying to measure all the inputs. We started by really looking at the qualitative data that we had collected and pulling out and identifying the symptoms that we were seeing on the ground by observing people and talking to them.

We came up with a list of symptoms and they ranged from things like seeing people arrive early at appointments because their bus schedule could only get them there at a certain time and having to wait a long time for their appointments. We saw people rescheduling trips frequently or having to skip trips because they had a ride arranged to go someplace, and then the ride fell through. We created this long list and then we took them to a number of experts on rural poverty and nonprofits who work with low-income populations and asked for input on the questions and whether we were missing anything.

We then started a process of conducting 52 cognitive interviews with people to help us understand whether the questions we were asking are being answered and understood in the way that we’re intending so that we know that we’re measuring the things we want to measure. It’s really tricky to create simple survey questions that don’t overtax people’s cognitive load and make them think too hard because then often you get bad data. We then fielded a survey that was largely comprised of people we thought would be transportation insecure who lived below the poverty line. Through that, we came up with a preliminary index that had 16 questions on it. A few years later, we conducted a second survey with a nationally representative sample to try to replicate and validate that initial index. We made some tweaks to some of the questions, and that’s how we arrived at the validated 16 item questionnaire that created the data and the findings that you’ve seen.

Gould-Werth: I just wanted to also emphasize that in the early stages of the research, it was really important to us to include people who are high income and not experiencing transportation insecurity as well as low income. So, when we were doing those cognitive interviews and fielding our first survey, we included transportation secure people because we wanted to see when we were getting false positives as well as false negatives.

And was South Bend (Ind.) the first city to actually put this in action?

Murphy: We’ve had a lot of interest from different cities. The city of Detroit has a mobility innovation office that at one point expressed a lot of interest in using the index in their planning work. The city of South Bend is another. We’ve had people from Madison, Wis., and also the city of Chicago also reach out. And their interests have really been all over the place. A lot of cities want to use this as a metric to understand what percentage of the people in their region are transportation insecure. Others are really interested in using this as a metric to track trends over time so they can see how conditions are changing and how investments in transportation are affecting transportation insecure people.

That doesn’t mean that they’ve adopted it. Our index is 16 items: it’s long. And so, we are working currently on creating a shorter form that will have between three and six items. But to the extent that some version of a short form has been adopted, the city of South Bend is using the index as an evaluation tool. They have a project called Commuters Trust that pools together large employers in the city of South Bend that are really interested in figuring out ways to help their employees get to work on time and more reliably. Their project was to provide people bus vouchers and Uber vouchers, things like that, to hopefully help people get to work on time. They’re using the Index to get a baseline for the level of transportation insecurity among participants and then to see if these interventions are helping. The interests of cities that have contacted us have really ranged from evaluation projects to helping them plan for where to put investments in transportation in the future.

And how would that process work for a city that’s potentially interested in using this in some way?


Gould-Werth: Anyone who wants to use the Index—cities, other researchers, people who are working on developing interventions, nonprofits—we are so happy to engage with them and give advice. It’s really not that hard of a tool to use and especially won’t be when we get it down to three to six items. It’s a standard list of questions and then you administer it in a survey. It should be pretty easy for anyone to administer.


And is your recommendation to give that to a specific population or to everyone who’s using public transportation? Or does that vary from city to city?

Gould-Werth: I think it would vary based on what the city’s goals are. If you’re interested in improving your public transit system, maybe you do want to survey the people who are using it, but maybe it’s also super important to survey the people who aren’t, the people for whom the public transit system is not needing their needs.

Murphy: Just to piggyback on something Alix said about service providers and practitioners, this is really a tool that can be used by so many different groups. Healthcare practitioners are one group that are really interested in using it as a screening tool and potentially also non-profit organizations that can provide it to the people, patients or clients that come through the door and ask them this series of questions.

And how has COVID changed or not changed this process? It’s had a tremendous impact on public transportation. Has that changed the way you’re doing things in any way?

Gould-Werth: I think it just makes us more interested to continue this line of research. All the data that we’ve collected thus far is pre-pandemic and in our previous nationally representative survey, we were able to get prevalence estimates and find that one in four people in the United States experience some level of transportation insecurity. Did that number go up or down? We have hypotheses, but I think it’ll be really exciting to get new data and really test those hypotheses.

Murphy: This is not a question you’re asking, but our dream for this index is that it somehow could be incorporated into reoccurring nationally representative surveys, like we do the Food Insecurity Index, to really trace this on a regular basis. When we collect new data, we’ll have a better sense of what 2018 to 2022 looks like. But in an ideal world, we would have this on reoccurring surveys to see how all of these changes that we experience constantly, whether it’s gas prices, inflation, or a new a new bus line being opened up, are influencing transportation insecurity across a population.

Has the data you’ve compiled thus far led you to particular policy applications that you think would be helpful?

Gould-Werth: We are at such early stages of analysis that we haven’t done evaluations of these interventions, but that’s something that we would really like to see. And I think one of the things that we have found though is that the biggest predictor of transportation insecurity is poverty. So, any policy that is addressing poverty, whether that’s the expanded Child Tax Credit or higher minimum wage, likely would be addressing transportation insecurity. That’s one option: these broad programs to decrease poverty levels.

But I think Alex and I are really excited about interventions that happen at the individual level to address transportation insecurity directly. One thing that’s been challenging about this work is that we come from sociology and poverty and inequality studies, but there’s a whole world of urban planners and scholars in other disciplines who are thinking deeply about these problems. A lot of the interventions that they focus are the broader population level—let’s build a new sidewalk, for example. What we’d like to see is more targeted interventions like SNAP for food insecurity or housing vouchers for housing insecurity. The new bill in D.C. offering $100 a month to use on transit is an example or making transit free to people with low incomes. There’s a pilot in Washington state’s TANF office where they gave people a certain amount of money to spend on any transportation need they had. We’re really excited that our index could be used to test and see which approaches might work.

Murphy: I’ll just say that I think it’s an exciting time to be thinking about these things because these are the debates that are happening right now. People are floating this idea of universal basic mobility. How can we get people a guaranteed ability to get to places that they need to go? That’s the million-dollar question right now.

And if I could add just one more point that Alix and I have talked a lot about. You are like us in that you come from the poverty studies world where people tend to study food and family arrangements and education and employment and all these things. And one of our observations is that when you talk to social scientists or you talk to people in this world and you say transportation matters, they always say, “Oh, obviously.” And yet it’s sort of treated as auxiliary, like it’s separate, people need to get to the grocery stores so that they can get food and they need to get to the school so that they can have education, but it’s not treated as a domain of interest in and of itself. And I think that that’s what we’re really interested in, thinking about transportation as a domain to be studied in and of itself.


Alix Gould-Werth is the director of Family Economic Security Policy at the Washington Center for Equitable Growth.



Alexandra Murphy is an assistant professor of Sociology at the University of Michigan.

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