By Daniel Comeaux
New York City’s curbs are an incredible asset. They are also a contested one, and increasingly so. These facts, which will likely come as no surprise to readers of this blog, were the inspiration for my recently completed master’s thesis project. In that report, Curb Space and Its Discontents, I analyzed the allocation and usage of the curb in New York City. I used Coord’s data on the existing profile of curb usage to inform my analysis, as well as my final recommendations.
Below, I share more about the analysis I conducted, how Coord’s data played a role, and some of my takeaways from the experience.
An Approach to Understanding the Curb
I developed my recommendations through analyses of data from Coord, NYC DOT, and others. I also supplemented these analyses with a review of the existing literature and findings from twenty interviews with transportation professionals across the US.
Broadly, I aimed to answer three questions.
First, how can we evaluate the costs and benefits of on-street free parking vs. alternative curb uses? While on-street free parking is the most common use of NYC’s curbs, there are many other possibilities (and as Figure 1 shows, the number of alternatives continues to increase). In the report, I reviewed the costs and benefits not only of free parking but also of five other uses: bike parking, parklets, Neighborhood Loading Zones, bike lanes, and waste collection zones.
Figure 1: Timeline of Curb Uses in NYCSources: NYC DOT, Press Reports
Second, how would these metrics vary across NYC? I focused my report on one neighborhood in each of NYC’s five boroughs, ranging from Manhattan’s Upper West Side to St. George in Staten Island.
Third, what would the impacts be of reallocating curb space? Changes to the curb are not made in a vacuum. They usually involve politically fraught debates about replacing one use, like free parking, with another. In response, I developed a model to estimate the impacts of reallocating the curb, including costs, emissions, safety, mobility, and more. I also explored the distribution of these impacts, since different curb allocations are useful to different groups of the city’s residents and visitors.
The Importance of Coord’s Data in the Analysis
Coord provided me with the curb usage rules for every piece of the curb in my five target neighborhoods. This inventory allowed me to develop a more accurate picture of the current state of the curb, and to understand how that varied across the city.
Using Coord’s curb use inventory, I found that in every neighborhood I evaluated, free parking represented more than half of the available curb space (not including uses like paid parking that convert to free parking overnight). I was also able to integrate these findings with my analyses of other data sets.
Figure 2: Comparison of the Percent of Curb Space Allocated to Free Parking with the Share of Neighborhood Households Parking A Car on the Street
Sources: Coord, American Community Survey, NYC Mobility Survey 2018
I found that in every neighborhood I considered, the share of the curb dedicated to free parking far exceeds the share of the households in the neighborhood who rely on that parking. This might be expected in a neighborhood like the Upper West Side, where fewer than a quarter of all households own a vehicle. But it was also true in (relatively) more car-centric neighborhoods like Bay Ridge and St. George, with the rate of on-street parkers less than half the share of curb space dedicated to free parking.
Coord’s curb inventory also allowed me to put the scope of potential changes in context. It is possible to consider a change to the curb in the abstract - for example, replacing 40 feet of free parking with a neighborhood loading zone. But it is more useful to consider it given the realities of the curb today: what share of a neighborhood’s parking does that represent? How many other pickup and dropoff zones are nearby? Having a baseline from Coord allowed me to answer those questions, and others, which I could then incorporate into my broader recommendations.
Based on my analyses, I developed recommendations to improve curb space allocations in NYC. I have highlighted several of them below.
First, having data on the curb is critical to informed decision-making. That includes both the current allocation of the curb and how the curb is actually used. Unfortunately, these data have historically been scarce - a fact that makes the data and platforms being developed by organizations like Coord so exciting.
Of course, data are not the answer to every problem of the curb. It also matters what cities do with the data. And that’s why the second takeaway I want to highlight is the importance of thinking systematically about the curb. The decisions public officials make about how to allocate the curb have real impacts on the residents they serve - emissions, available job opportunities, traffic deaths, and more. And so it is crucial that public officials weigh these impacts, and their distribution, when deciding whether to alter or maintain the current state of the curb.
One consequence of this approach I found particularly compelling was the attractiveness of curb uses that combine benefits. For example, NYC’s Neighborhood Loading Zones allow pickups and dropoffs for both people and goods over a twelve-hour period, recognizing that the demands for these different uses complement each other over the course of a day. Elsewhere in the US, officials in Washington, DC recently launched a new program of on-street micro-mobility parking. In addition to capturing the mobility benefits of these zones, DC officials strategically place these zones at the end of the block to “daylight” the intersection, increasing visibility and safety for pedestrians.
Figure 3: A Micro-mobility Corral in Washington, DC
Source: District Department of Transportation
Finally, while successfully changing the allocation of the curb is difficult, there are strategies that can increase the likelihood of success.
In some cases, that might be getting and using the kinds of data that Coord can provide on the allocation and usage of the curb. Those data can help public officials make better decisions about where changes in the curb are needed. They can also help those officials communicate the importance and impacts of changing the curb.
With or without those data, cities can also follow the model of those like Seattle and San Francisco which have adopted “hierarchies” of their curb - official preferences for which uses should get more, or less, priority. Of course, the specifics might vary from city to city: for example, waste collection on the sidewalk is not the same concern in my hometown of Lafayette, LA that it is in NYC! But the principle that curbs should be for people, and not just cars, is applicable just about everywhere. And I appreciate Coord’s help in developing a report that makes that case.
If you would like to learn more about Daniel's analysis and recommendations, you can download both the full report and an executive summary on his personal website. The Kennedy School awarded the project the award for Outstanding Policy Analysis Exercise, an honor given to only one project per year. In addition, the project received the HKS Taubman Center’s Urban Prize, which recognizes exceptional reports focused on issues of state and local government.