Cartographer Chat with Courtney Jentzen and her Illustrated Map of Detroit’s Cass Corridor Neighborhood

What is your map?

A map of Detroit’s Cass Corridor neighborhood. Created in Spring of 2023 as a collaboration with City Bird and Midtown, Inc. 

How did you come to make this map? What’s the story?

Andy Linn, from City Bird, approached me about creating a map with the help of Midtown, Inc. that would highlight just how walkable Detroit’s Cass Corridor is. We all wanted this map to highlight all the great small businesses that make this neighborhood so special and accessible. 

What are you most proud of in the map? What stood out to you? What details do you enjoy about the map?

I’m most proud of how much we worked into the map! Creating maps is a very difficult task so I was glad we were able to include all the locations we wanted while still having there be some design flair. My favorite part was creating the little people. I thought of all the interesting and inspiring people I know and see daily around here and used them as inspiration on the map. I love the little local easter eggs hidden throughout the map as well, if you know you know. 

What in your background has drawn you to maps?

I’m an illustrator and have been creating maps for a long time. I love the storytelling aspect of them. These maps aren’t meant to be 100% functional. They are meant to tell a story and give you a sense of an area. You can learn so much about a neighborhood by just taking a quick glance at an illustrated map. Everyone has access to a smartphone nowadays so no one “needs” this map but it’s the storytelling component that makes it an important piece. 

Map: Gentrification Alley and Air Quality in Detroit

The G-word always invites controversy and confusion, but from the authors own work:

To assess gentrification, longitudinal analyses were performed to examine median household income, percentage with a college education, median housing value, median gross rent and employment level. 

Hutchings H, Zhang Q, Grady S, Mabe L, Okereke IC. Gentrification and Air Quality in a Large Urban County in the United States. Int J Environ Res Public Health. 2023 Mar 8;20(6):4762. doi: 10.3390/ijerph20064762.

There are issues with assessing geospatial phenomena using ZIP code level data, but these findings give pause and hopefully encourage a greater deep dive.

Map: Exploring Detroit Population Change from 2010 to 2020

Sometimes I make a map because I’m unhappy with what exists out in the data-sphere already. This is an instance of that exact scenario. A local organization put out a map of population change between the decennial censuses (censi? censai?) using a poorly chosen color scheme and a misleading legend and data categories. What really stood out most was that there was 5,400% (WTF) increase in population somewhere in the city. I assumed it had to be an error or a mistake, but I also could not tell from the map where such a massive population increase occurred.

There was a single census tract in the Hubbard-Richard/Corktown/West Side Industrial area that gained significant population since 2010. I racked my brain for a long time trying to figure out why or what developments contributed to the area going from 4 people in 2010 to 220 in 2020. I had to reach back in time and recall that many of the empty warehouses were converted into lofts. The Hudson (2011) was one of the first with about 80 units, then The Coat Factory Lofts (2014) with 62 units, and most recently The Assembly (2019) with 32 units. Most of the units are one bedroom with a handful of two and three bedroom units. In all the 174 units house an estimated 240 people.

What had been a relatively empty industrial and warehouse square of the city now houses quite a few more people. New amenities like the West Riverfront park and even more housing are coming soon as Ford Motor Company redevelops the train station.

Map: Path of Least Surveillance through Greater Downtown Detroit

Ever since I saw the similarly named map of Manhattan, NYC in an Atlas of Radical Cartography I have wanted to recreate the concept for Detroit. The hardest part as usual was data collection or data access. Collecting data on surveillance and CCTV cameras would have taken forever, but was possible. One of the Data, Mapping, and Research Justice workshops that I ran tested data collection in the Cass Corridor, which had surprisingly few cameras. I randomly stumbled upon the CCTV data variable on Mapillary, which is an open source streetview platform. Submitted streetview images are scanned to extract multiple data points and cameras happen to be one. The data is not perfect, but is fairly reliable since the City of Detroit itself is capturing and submitting streetview imagery to Mapillary.

Now, Detroit is a city full of security and surveillance: Project Greenlight, Shotspotter, expansion of Automated License Plate Readers, etc. Wayne State University Police Chief Holt is quoted as saying, “Anywhere on campus, if you look up, I can see you.” The WSUPD managed the camera apparatus that was installed prior to the 2006 Super Bowl XL until the Detroit Police were able to take on the resource via their $20 million Real Time Crime Center. WSUPD has at least 380 external cameras across campus properties.

The Gilbert/Bedrock/Quicken group has installed at least 850 cameras on the properties that they own, manage, or ones just wish to own like American Coney Island and 1515 Broadway. The offending entity turned out to be Compuware security, but many if not all major Downtown companies have been sharing and collaborating on surveillance for many years.

In all I found 2,943 surveillance cameras in the Greater Downtown 7.2 sq mi area. The best I could do was find a route that encounters at least 41 cameras within 25 feet of the route. The route starts in New Center Commons on Third Street and ends up at Hart Plaza, which is full of cameras. Once you reach the Central Business District it is impossible not to be captured on camera or possibly surveilled.

Surveillance isn’t safety. Check out the Green Light Black Futures Community Safety Survey

Map: Brewing Change Among Detroit’s Coffee Shops

In the last few years, Detroit lost some staples of the city’s coffee and gathering spaces, including:

  • Avalon Bakery (original location)
  • Astro Coffee
  • Bikes and Coffee
  • Great Lakes Coffee
  • Starbucks (Midtown)
  • 3 Tim Hortons locations

Despite all the closings (n=21), the city is only down by one coffee shop overall from 84 to 83 coffee shops. Since 2021 there have been 20 new coffee shops or pop-ups launched. The focus for coffee remains Downtown and Midtown, but the neighborhoods remain under-served by third places (not home, not work).

Other staples got new life as renewed coffee shops:

  • Detroit Rosa (former A Public Square, former Towne Hall Caffe)
  • SPKRBOX (former Urban Bean Co.)
  • Red Hook – Midtown (former Great Lakes Coffee)

Still more moved to grow in new locations:

  • Anthology relocated to Eastern Market
  • Cairo Coffee moved into Spotlite Detroit space
  • Avalon moved in to share space with Jolly Pumpkin

Gathering spaces in Detroit are a hot commodity and not easy to come by, so the loss of just one is usually a substantial hit to the community. A handful of new baristas are trying their hand at pop-up coffee and we can’t wait until they have some physical space:

Map: Reimagined Detroit Bus Routes Comparison 2023

Last week I shared that DDOT was creating a new map and entirely new bus routes for the city. DDOT Reimagined now has an excellent StoryMap that includes a map slider to compare existing and reimagined routes.

The site contains feedback, draft proposals, bus route specific changes, and a place to provide your own feedback. Help DDOT Reimagine transportation in the city and submit your comments!

HT @DE_Gifford

Map: Metro Detroit Coney Regions

Detroit is the only real city to get a coney dog.

Yet, the coney dog’s popularity has spun up a number of regional coney island chains: National, Leo’s, and Kerby’s. Many suburban metro Detroiters have a preference and meet their friends and family at the local coney island restaurant. National is more Macomb County territory while Kerby’s is very north-central in its locations. Leo’s is by far the most ubiquitous and readily available coney island spot in the region.

As with many community amenities like grocery stores, taco restaurants, and retail, Detroit gets passed over time and time again. Detroit doesn’t need chains or national brands. Detroiters make a way with no way. Coneys are no different. The city has the greatest density and all independent establishments.

Map: Current Detroit Transit Weekly Ridership

This map is part of the DDOT Reimagined effort to create an all new transit map for the city that better serves the city.

Ridership remains high on the city’s major commercial corridors and most heavy along Woodward. Hopefully we will see a significant investment in transit that modernizes and makes DDOT the reliable and frequent service that Detroiters deserve.

Detroit Blossoms and Fruit Trees Map

I mapped Detroit’s fall colors and have often been asked where to find fruit trees. Spring seems the perfect time to locate blossoms like Pear and Cherry trees while also highlighting some other fruit tree clusters.

The map noticeably has no Cherry trees, which I think is an error with the dataset. However, as far as I know, only Belle Isle has Cherry trees. The streets are labeled on the map where there are multiple fruit trees. Detroit has a wide distribution of Apple and Pear, but also some dense clusters of Hackberry or Chokeberry.

There is an interesting spatial pattern where neighborhoods further from downtown have more fruit trees as well as the line of fruit trees that mark the city’s Westside. I’m again very thankful that Dr. Dakota McCoy and team have created this cleaned up dataset from disparate tree sources.

Detroit Parking Map 2023

Visually, Detroit’s central business district (CBD) looks to be all parking. The Parking Reform Network (PRN) found that 30% of the CBD is devoted to parking. The absurdity of a car-centric city has harmed Detroiters far more often than supported the growth and vitality of the city.

Map: Current Flooding Risk in Detroit 2023

Detroit has the potential to anchor a future climate change haven as people migrate away from the a dry and scalding West or a flooded South and East. The city, like many in the Rust Belt, is heavily industrial and has a legacy of not maintaining the cleanliness and ecology of the coastline. The city is also decades behind on infrastructure upgrades to roads, pipes, electrical, etc.

The greatest climate risk for the Great Lakes region is heavy rainfall which leads to flooding. The city and its neighbors have seen these impact already with poor drainage on expressways and a lack of green stormwater runoff infrastructure and too many parking lots. The data here comes from First Street Foundation Flood Model which is a national model that shows the risk of flooding at any location. As the data shows, flood risk varies across the city and the areas like Jefferson Chalmers and Southwest Detroit/Dearborn highlight on the map.

Map: Hamtramck Master Plan – Building Condition 2020

Detroit is more than just the city, it is also the bowtie cities of Hamtramck and Highland Park. Hamtramck often gets referenced as a sort of neighborhood of Detroit even when it exists as its own separate municipal entity. The City of Hamtramck is dense, multi-cultural, and provides numerous community assets to surrounding Detroit areas.

This map from the 2020 Hamtramck Master Plan shows the vibrancy and density of Hamtramck housing and commercial property.

Map: Extent of Blight in Detroit 1962

This map is included in a report titled: “Renewal and revenue: an evaluation of the urban renewal program in Detroit” by the City Planning Commission in 1962. By this time urban renewal had already been a wide ranging and destructive force since the 1950s with mass slum clearance and highway construction. The map shows areas of blight and/or redevelopment shaded in. Blight has been a mayoral focus in Detroit since the time of Mayor Jeffries in the 1940s.

Cartographer Chat with Aurélien Boyer-Moraes and his updated redesign of Detroit bus system map

What is your map (title, year, etc.)

This is my latest version of the public transport of Detroit (DDOT) network map, as of 2022.

How did you come to make this map? What is the story?

This is a long story but to make it short it goes back to an old fascination about Detroit and its electronic music scene when I was a teenager in the mid-1990s. I came across a fantastic documentary (Universal Techno if I remember correctly) on the French public TV channel Arte and at the time I had no internet, no computer at all, and I discovered all of a sudden Detroit, its unique urban scape, this sound (from the late 1970s onward), it was stunning, I was mesmerized. I was already looking at many things linked to cities, architecture, urbanism, mass transit networks. I read architecture magazines at the city public library because they were (and still are) way too expensive. Later, when I decided to design a transport system map as an exercise (an important one), this city came back to my mind as the first choice (cf point 4). It was also the only American city of which I had a streetmap paper copy in 2000, I had found in a defunct bookshop specialized in maps in Nantes.

What are you most proud of in the map? What stood out to you? What details do you enjoy about your map?

Its straightforwardness and strong coherence: the relationship between the lines on the map and their headways, as exposed underneath in a chart; everything is closely integrated, everything has a clear function. The map serves a double purpose: showing the network as well as depicting its offer (with its variation during the day or the week). Every important information is there and the map is still light, well “spaced out” as one might say for a book composition, I come from graphic design after all. I consider it is the clearest I’ve ever drawn so far.

What in your background has drawn you to maps?

I was quite a bookworm, I have a solid “paper” or “everything printed” background. Early on I discovered I enjoyed as much examining maps (all kind, from the topographic to the synthetic chart of a statistical atlas) as reading fiction, they had the same power to me, they open so many things as well as convey so much. So during my further studies in design, as soon as I could, I tried to conceive a map: it had to be a public transit system map, because of the kind of information it had to convey I wanted to deal with visually. The first map I’ve done properly on a computer, all vector, was Detroit’s―and here we are (slightly more than two decades later).


Aurélien Boyer-Moraes: I am binational French and Portuguese, living between Lisbon and France. I’ve designed official maps for several networks of French cities (most notable: Lyon métro-tram-trolleys, Dijon, Metz) as a freelancer for Attoma until 2016.

Map: de Lery’s Copy of de Boishebert’s Map of Detroit 1731

This map caught my eye because I had never seen it before. The French-Canadian Heritage Society of Michigan shared the map courtesy of the Bibliothèque et Archives Canada / Library and Archives of Canada, but the link is broken now.

I’ve posted just one other map from 1731 and this might be a copy of that map. Gaspard-Joseph Chaussegros de Léry was King Louis XV’s Chief Engineer of New France. He made many maps of the territory that included Detroit as a key military, trade, and transportation location. His other work included the Plan of Detroit (1749) among others.

This map is a copy, which was very common practice, of Henri-Louis Deschamps de Boishebert. de Boishebert was a military leader and commander during the French and Indian War across the territory of New France. He also created one of the very first maps of French ribbon farms in 1731.

Map: Neural Networks and the Built Environment of Detroit

Researchers found that neighborhoods equipped with indicators of development like sidewalks or crosswalks were linked to reductions in obesity and high blood pressure. They also found that more road signs and street lights correlated with lower prevalence of high cholesterol and cancer, as well as reduced depression and smoking. 

These findings are based on training a computer model to identify and label a series of features in the built environment. The study analyzed 164 million Google Street View images harvested from across the US. The images were then compared to socioeconomic and demographic data from the US Census and Centers for Disease Control and Prevention (CDC).

The project is exciting and novel with the potential to reduce time to assess built environment indicators, but a critical missing element that all too often haunts Detroit is the inability for databases and models to assess quality of assets in the built environment. A model may find sidewalks everywhere, but fails to categorize many Detroit sidewalks as impassable. Other computer models from MIT based on Google Street View (2014) oddly ranked streets full of cars as less safe than vacant lots with unsafe structures.

These maps based on Google Street View to categorize the built environment, as many data projects do, paint Detroit red. In this instance, the data in question is positive with Detroit presenting with more sidewalks and crosswalks – but with high rates of heart disease, pedestrian vehicle fatalities, and smoking it is hard to see the computer assisted value.

Map: Detroit Black Developers and Building Permits

Detroit is a city on the move. New construction and real estate development has been on a break-neck pace that even a COVID slowdown can’t seem to stifle. As a result the important question of equitable opportunity is elevated. A major drawback for Black developers was in the State of Michigan’s “Michigan Strategic Fund” selected the Detroit Downtown Partnership with Bedrock Detroit overlooking all of the Black developers in Detroit that were pushed to submit applications.

Mayor Duggan’s 2023 State of the City address repeated mentions of many real estate projects led by 33 Black developers. It is hardly an exhaustive list of Black developers nor does it even encompass all of the projects they are working on, but it still provides an important marker for where equity is in the real estate equation. Other efforts like Capital Impact’s Equitable Development Initiative (EDI) has supported 56 BIPOC real estate developers, property managers, and investors. Building Community Value has trained 294 individuals interested in real estate in underserved neighborhoods with 85% BIPOC representation.

The Mayor’s list of Black developer projects is focused in the areas where development is already heavily invested in. The exciting piece is that Black developers are involved and benefiting in the higher stakes projects, but there are still numerous underserved neighborhoods waiting to see the same levels of investment as Downtown and Midtown.

Map: Detroit Suburban Bus Service 1925

Detroit hasn’t always been a bus city (which I guess is still questionable based on current bus performance). David Gifford shared this map from Book 3, When Eastern Michigan Rode The Rails by Schramm, Henning and Andrews. In 1925, the Western suburbs really stand out with multiple bus lines stretching across Wayne County. There was similar heavy bus service in the Westside of Detroit, but not the Eastside. Based on the proposed Woodward line all the way to Pontiac I’m going to say there should have always been an elevated light rail built along M1.

Map: DTE Outage Map by ZIP Code February 2023

The February 2023 ice storm decimated the already under-invested in infrastructure of DTE’s electric grid. Over 620,000 customers were impacted across Southeast Michigan and many still today have not had their power restored after 7 days of no power. Eric Lau of Michigan Daily created this timeline map of DTE outage data from their outage map’s API, Kubra Storm Center. In the last year DTE generated over $1 billion in profits and announced postponed maintenance in 2023 to it’s shareholders the same day that the ice storm hit.

Map: Typologies in the Detroit Innovation District 2015

When the Detroit Innovation District (DID) launched in 2015, there was very limited information as to what that meant and even less information on what new funding or resources would support said “innovation.” I just recently stumbled upon these analyses completed by Interface Studio that maybe proves the point that the groups pushing the DID didn’t have the plan fully fleshed out either. When it comes to innovation districts, Detroit’s was massive (4.4 sq mi vs. 1 or 2 sq mi) and the end recommendation was to focus on micro-districts within the DID.

Detroit Rental Map

In an effort to improving living conditions and ensure all landlords were compliant with city ordinances, the City launched a mass hiring of building inspectors and ZIP code by ZIP code inspections of registered or suspected rental housing. Many advocates were concerned that this might lead to an inadvertent mass eviction crisis, but eviction is already too commonplace in Detroit. The effort has been very slow and difficult to manage, but has continued. Many tenants have been able to win court cases because delinquent landlords have been shown not to be compliant with city ordinances.

The improvement of housing in Detroit will require upgrades and assurances of safety and quality. This map helps keep track of where landlords have kept up with health and safety compliance or not.