There might be some empirical gymastics here (I did not read the paper), but this kind of study is one reason I find economics fun.
We find that reductions in traffic congestion generated by E-ZPass reduced the incidence of prematurity and low birth weight among mothers within 2km of a toll plaza by 10.8% and 11.8% respectively.
The point I would remind my students is this: if your goal was to think about ways to improve infant health, I do not think this would be something you came up with. The magnitude of these effects seem quite large, and it would be useful to see how they compare to other interventions, particularly in terms of costs and benefits.
Finally, this is an example of when a government program (intended to reduce traffic congestion) seems to have worked to reduce congestion, and also had a positive spillover effect. Of course, I’d also remind you to beware the unseen. If the roads and transportation system were private, do we think it would have taken so long to develop and implement this and other congestion saving devices?