Where the sidewalk ends

Date:
March 16, 2023
Source:
Massachusetts Institute of Technology
Summary:
Most cities don't map their own pedestrian networks. Now,
researchers have built the first open-source tool to let planners
do just that.

Researchers have built TILE2NET, an open-source tool that uses
aerial imagery and image-recognition to create complete maps of
sidewalks and crosswalks. The tool can help planners, policymakers,
and urbanists who want to expand pedestrian infrastructure.


Facebook Twitter Pinterest LinkedIN Email
FULL STORY ==========================================================================
It's easier than ever to view maps of any place you'd like to go --
by car, that is. By foot is another matter. Most cities and towns in
the U.S. do not have sidewalk maps, and pedestrians are usually left to
fend for themselves: Can you walk from your hotel to the restaurants on
the other side of the highway? Is there a shortcut from downtown to the
sports arena? And how do you get to that bus stop, anyway?

==========================================================================
Now MIT researchers, along with colleagues from multiple other
universities, have developed an open-source tool that uses aerial
imagery and image- recognition to create complete maps of sidewalks and crosswalks. The tool can help planners, policymakers, and urbanists who
want to expand pedestrian infrastructure.

"In the urban planning and urban policy fields, this is a huge gap," says Andres Sevtsuk, an associate professor at MIT and a co-author of a new
paper detailing the tool's capabilities. "Most U.S. city governments know
very little about their sidewalk networks. There is no data on it. The
private sector hasn't taken on the task of mapping it. It seemed like
a really important technology to develop, especially in an open-source
way that can be used by other places." The tool, called TILE2NET,
has been developed using a few U.S. areas as initial sources of data,
but it can be refined and adapted for use anywhere.

"We thought we needed a method that can be scalable and used in different cities," says Maryam Hosseini, a postdoc in MIT's City Form Lab in the Department of Urban Studies and Planning (DUSP), whose research has
focused extensively on the development of the tool.

The paper, "Mapping the Walk: A Scalable Computer Vision Approach for Generating Sidewalk Network Datasets from Aerial Imagery," appears
online in the journal Computers, Environment and Urban Systems. The
authors are Hosseini; Sevtsuk, who is the Charles and Ann Spaulding
Career Development Associate Professor of Urban Science and Planning
in DUSP and head of MIT's City Form Lab; Fabio Miranda, an assistant
professor of computer science at the University of Illinois at Chicago;
Roberto M. Cesar, a professor of computer science at the University of
Sao Paulo; and Claudio T. Silva, Institute Professor of Computer Science
and Engineering at New York University (NYU) Tandon School of Engineering,
and professor of data science at the NYU Center for Data Science.

Significant research for the project was conducted at NYU when Hosseini
was a student there, working with Silva as a co-advisor.

There are multiple ways to attempt to map sidewalks and other pedestrian pathways in cities and towns. Planners could make maps manually,
which is accurate but time-consuming; or they could use roads and make assumptions about the extent of sidewalks, which would reduce accuracy;
or they could try tracking pedestrians, which probably would be limited
in showing the full reach of walking networks.

Instead, the research team used computerized image-recognition techniques
to build a tool that will visually recognize sidewalks, crosswalks,
and footpaths.

To do that, the researchers first used 20,000 aerial images from Boston, Cambridge, New York City, and Washington -- places where comprehensive pedestrian maps already existed. By training the image-recognition model
on such clearly defined objects and using portions of those cities as
a starting point, they were able to see how well TILE2NET would work
elsewhere in those cities.

Ultimately the tool worked well, recognizing 90 percent or more of all sidewalks and crosswalks in Boston and Cambridge, for instance. Having
been trained visually on those cities, the tool can be applied to other
metro areas; people elsewhere can now plug their aerial imagery into
TILE2NET as well.

"We wanted to make it easier for cities in different parts of the world to
do such a thing without needing to do the heavy lifting of training [the tool]," says Hosseini. "Collaboratively we will make it better and better, hopefully, as we go along." The need for such a tool is vast, emphasizes Sevtsuk, whose research centers on pedestrian and nonmotorized movement
in cities, and who has developed multiple kinds of pedestrian-mapping
tools in his career. Most cities have wildly incomplete networks of
sidewalks and paths for pedestrians, he notes. And yet it is hard to
expand those networks efficiently without mapping them.

"Imagine that we had the same gaps in car networks that pedestrians have
in their networks," Sevtsuk says. "You would drive to an intersection
and then the road just ends. Or you can't take a right turn since there
is no road. That's what [pedestrians] are constantly up against, and we
don't realize how important continuity is for [pedestrian] networks."
In the still larger picture, Sevtsuk observes, the continuation of climate change means that cities will have to expand their infrastructure for pedestrians and cyclists, among other measures; transportation remains
a huge source of carbon dioxide emissions.

"When cities talk about cutting carbon emissions, there's no other way
to make a big dent than to address transportation," Sevtsuk says. "The
whole world of urban data for public transit and pedestrians and bicycles
is really far behind [vehicle data] in quality. Analyzing how cities
can be operational without a car requires this kind of data." On the
bright side, Sevtsuk suggests, adding pedestrian and bike infrastructure
"is being done more aggressively than in many decades in the past. In the
20th century, it was the other way around, we would take away sidewalks to
make space for vehicular roads. We're now seeing the opposite trend. To
make best use of pedestrian infrastructure, it's important that cities
have the network data about it. Now you can truly tell how somebody can
get to a bus stop."
* RELATED_TOPICS
o Earth_&_Climate
# Geography # Environmental_Science # Environmental_Policy
# Air_Quality
o Science_&_Society
# Transportation_Issues # Surveillance #
Travel_and_Recreation # Urbanization
* RELATED_TERMS
o Automobile_safety o Artificial_reef o
Urban_planning o Topographic_map o Irrigation o
Traffic_engineering_(transportation) o Aerial_photography
o Vehicle_propulsion

========================================================================== Story Source: Materials provided by
Massachusetts_Institute_of_Technology. Original written by Peter
Dizikes. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Maryam Hosseini, Andres Sevtsuk, Fabio Miranda, Roberto M. Cesar,
Claudio
T. Silva. Mapping the walk: A scalable computer vision approach for
generating sidewalk network datasets from aerial imagery. Computers,
Environment and Urban Systems, 2023; 101: 101950 DOI: 10.1016/
j.compenvurbsys.2023.101950 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/03/230316140925.htm

--- up 1 year, 2 weeks, 3 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)