Q&A: Xiaoxia Dong, Assistant Professor of City & Regional Planning

For Assistant Professor of City & Regional Planning Xiaoxia Dong (MCP’14, PhD’20), who goes by "Summer" and joined the standing faculty this year, Philadelphia played a central role in his graduate studies and is central to his research, which focuses on transportation safety and accessibility. In an interview, Dong, who earned both his Master of City Planning and PhD from Penn, describes the ways that sound planning has impacted Philadelphia, his approach to teaching data and statistical analysis, and his findings on the complex relationship between pedestrians and driverless cars.

How long have you lived in Philadelphia and what changes have you seen in your time here?

I did my master's between 2012 and 2014, then took a couple of years to work in the field as a transportation planner, before coming back in 2016 for my PhD, which I finished in 2020. I went to Johns Hopkins University for a postdoc before coming back in 2021 to be a full-time research associate and lecturer. I am thrilled to continue to work at Penn in my new role..

There have been some big changes in Philadelphia since 2012, including the new Comcast Technology Center, the Schuylkill Yards development, the renovation of Dilworth Park at City Hall. But there have also been less dramatic changes, such as the new protected bike lanes in the city, the Schuylkill River Trail Boardwalk, and the [introduction of the] 49 bus. These lower-profile projects show more incremental progress and really highlight the power of sound city planning to improving residents’ quality of life. I am hoping that in another 12 years we can look back and say the city has made good progress in addressing housing affordability, the homelessness crisis, and public safety. Hopefully, we can also look back and say the 76ers finally made it to the NBA finals [laughs]!
 

SEPTA’s Route 49 bus goes right past Meyerson Hall. Why do you bring that up as a sign of change?

The 49 bus, which started running in 2019, was designed by a Penn alum named Anita Davidson (MUSA’14). We overlapped the year she was at Penn. She went to work for SEPTA after graduation. She noticed that there is a transit gap between Brewerytown, Center City, and University City, meaning that for people who live in Brewerytown and work in University City or Center City, there's no easy transit connection. It's a great example of sound transit planning based on people's actual need. Anita used some of the analytic programs that I'm teaching in Quantitative Planning Analysis Methods–or “Quant”–this semester. It shows how the tools that we teach in our department have a lot of real-world applications, helping students succeed in professional practice.

"There's a lot of room for improvement on how we plan our streets."

Tell us more about Quant.

It is a required course for all the first-year master of [correct? Yes!] city planning students. The course teaches students how to use census data and various other data sources to portray neighborhoods, project population, and analyze the economy. I had the great pleasure of taking the course from Professor Emeritus John Landis and Professor [and Associate Dean for Research] Erick Guerra. I learned a lot from them and I'm eager to pass along their nuggets of wisdom to the next generation of planners.

One question that I get from students is, how are the methods that we learn in class being used by practitioners? As much as I can, I provide examples of the application of the course material in planning documents and analysis in the real world. I've also incorporated new modules to ensure that the course is relevant to topical issues. For example, we had a discussion about the potential economic impacts of the new 76ers arena using the concepts that the students learned in class.

Pedestrian and cyclist safety has been the subject of considerable research by your department. In October, you testified to the Philadelphia City Council on Bill 240657, commonly known as the “Get out of the Bike Lane” bill, which passed unanimously. Tell us about that bill and how your research led you to speak at City Hall.

First of all, I want to give a shout-out to Professor [and Chair of City & Regional Planning] Megan Ryerson. She recommended me for this amazing opportunity. This bill prohibits stopping or parking a vehicle in a bike lane in areas of the city with heavy bicycle traffic. It really is a necessary measure to improve safety and advance the city's zero traffic fatality goal [Vision Zero Philadelphia]. Increasing bike use takes cars off the road, which helps to mitigate congestion, reduce parking demand, and improve air quality. Bike lanes create safer environments for cyclists and encourage more people to bike. But parked cars make the bike lanes unusable, and the research has shown that they increase cyclists’ risks of crashing and falling.

Cyclists will choose not to bike if they don't feel safe while biking and having fewer cyclists means that the benefits of the city's investment in bike lanes may not be fully realized. Also, having cars parked in bike lanes forces cyclists to swerve into the vehicle lane, which disrupts traffic flow. This is a lose/lose for all users. The bill provides the city with an additional tool to enhance biking safety, so long as it is complemented with adequate enforcement. It will also place Philadelphia among several forward-looking peer cities that have banned parking and stopping in bike lanes, such as Chicago, Boston, San Francisco, and Washington, DC. It was really amazing to see the bill garner such support, and it was an honor to be part of the process.
 

Do you bike in Philadelphia?

I don't bike. I have a really short commute, and frankly, I don't feel safe biking in Philadelphia. I grew up in Beijing, which had a really serious biking culture. The bike lanes were often separated from vehicle lanes and were just as wide and well-maintained as the vehicle lanes. It was extremely safe and pleasant to bike there. Bike lanes were lined with trees and shaded. Coming from that to Philly, where streets are much narrower and there are far fewer cyclists, I don't feel very comfortable biking.

Your research on transportation focuses on emerging technologies and transportation, including ride sharing apps and driverless cars. What's on the horizon that we should be paying attention to?

It feels like we've been saying that driverless cars will be the next big thing in five years for the past 15 years. My research focuses on the travel behavior and mode choice impacts of driverless cars. In one paper I co-authored with Erick Guerra and Ricardo Daziano of Cornell University, we surveyed a thousand residents in the Seattle and Philadelphia metro areas. We examined their attitudes towards driverless cars from the point of view of pedestrians by asking if people would jaywalk more often knowing that driverless cars will stop for them. The respondents overwhelmingly supported reducing the speed of driverless cars in urban areas, and even disabling driverless features or driverless functions in areas with heavy pedestrian traffic. What we learned from these findings is that there's still a lot of mistrust of driverless technology.

We also found that some pedestrians would feel more comfortable jaywalking in front of driverless cars, knowing that the cars will stop for them automatically. If people become less concerned about jaywalking in the presence of driverless cars, it could create challenges for planners and traffic engineers to improve the traffic flow, especially in areas with heavy pedestrian activities such as Center City in Philly.

I think one of my biggest concerns is driverless cars being misperceived as the silver bullet to all of our transportation woes, and the anticipation of driverless cars drowning out tried-and-true strategies to keep our transportation system safe and efficient. Those strategies include promoting transit, building high quality pedestrian and cyclist infrastructure, reducing speed on urban streets, and so on. These are effective strategies for improving the safety and efficiency of our transportation system regardless of whether or not driverless cars become a reality. And they shouldn't be an afterthought.
 

New York City recently passed a bill allowing pedestrians to cross the street wherever they please. Jaywalking must complicate things when you study pedestrian safety.

If pedestrians deem it necessary to jaywalk, and if people are willing to take the risk, then that could indicate that we might need to put in more safe-crossing infrastructure when there's a need. There's a lot of room for improvement on how we plan our streets.
 

You research has involved a broad variety of players in transportation, from government agencies to startup companies. Can you describe an example of somewhere where you see transportation evolving in a way that it is being done right?

One that comes to mind is Indego, the Philadelphia bike share program, which provides an affordable and convenient travel option. It is a good example of effective collaboration from multiple stakeholders because the system's planning, implementation, and operations require buy-ins from local communities, City Hall, and private businesses. Placement of some docking stations has meant taking away parking in front of some private businesses, but not only have residents embraced the system, many are actually advocating for its expansion to serve more local needs. The system has been in service for almost 10 years now, and the support that it has garnered is really a vote of confidence from the local community. It's growing, which is happening fast, and people like it. All the stars have to align for an urban project like this to be successful.