Naomi Lee, a PhD candidate at the USC Price School of Public Policy, has won the Western Regional Science Association’s (WRSA) Charles M. Tiebout Prize for best student-authored paper.
Lee, who is pursuing a PhD in Urban Planning and Development, won the annual award for her research into e-scooter travel in Oakland and San Francisco, two cities that launched “slow street” programs during the COVID-19 pandemic to improve safety for pedestrian, bicycle, and scooter travel. The winning paper specifically examined how changes to those programs affected e-scooter travel volume.
In winning the award, Lee will present her research at the WRSA 64th Annual Meeting, which begins on Feb. 12 in Lake Las Vegas. The award also comes with a $1,000 cash prize.

“I am very excited,” Lee said of winning the award. “It’s a good motivation for me to continue studying travel behavior.”
U.S. cities took different approaches to implementing slow streets programs – which restrict access to vehicle traffic on certain roads – during the pandemic. Some cities phased in the program by adding or removing slow streets over time. Several local governments made the programs permanent; others eliminated them altogether.
This provided a rare opportunity to examine large-scale changes in street design that influence non-motorized travel, which has the potential to reduce traffic congestion and emissions that cause climate change.
“Naomi’s research on e-scooters is an excellent example of what we call ‘natural experiments,’” said USC Price School Professor Marlon Boarnet, who co-authored an earlier paper with Lee about slow streets and e-scooter travel.
Lee did careful, even painstaking work to build a good set of ‘experimental’ and ‘control group’ streets, using trip data from the e-scooter company Lime, Boarnet added.
“This has allowed her to get some of the best estimates anywhere on the impact of infrastructure on non-car travel,” Boarnet said. “Her research is making important contributions to urban planning and transportation studies.”

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Find Out MoreLee’s research revealed that the timing of removing slow streets played a role in whether travelers continued to use e-scooters on those roads. For example, slow streets that were quickly removed often saw a decline in e-scooter trips afterwards. However, later removals showed mixed results – some segments retained higher e-scooter use, while others did not experience significant changes.
The findings suggest that, when people are given enough time to adapt to such street planning changes, the results also highlight the importance of not only implementing slow streets but also strategically planning their transition – whether to permanent infrastructure or phase-out – to maximize long-term impacts on mobility.
Lee noted that slow street programs are relatively cheap infrastructure investments to promote non-car travel – compared to, say, building bicycle lanes.
“So”, Lee said, “one thing that we can learn from this is that sometimes a large, supportive infrastructure can be built with a relatively low budget – and it could be pretty effective.”