Roman Mars on the Design Hidden in Streets, Cities and Flags

Tyler Cowen welcomes Roman Mars, creator and host of 99% Invisible and co-author of The 99% Invisible City. Mars's work looks at the design decisions embedded in the everyday world, often in places people pass without noticing.

Cowen asks where the most attractive street signs are. Mars does not name a favorite: as he gets older, he values signs he can see. He notes that signs often serve drivers approaching an intersection more effectively than pedestrians standing on the corner.

Mars likes a street grid that lets a person navigate without constantly looking at a phone, but also enjoys getting lost in Venice's alleys. Cowen favors Swiss signs with spare lettering and colors that communicate the type of road. For Mars, the central question is whether a sign works for its user.

Why do older cars seem more distinctive than modern SUVs? Mars recalls designers who learned to recognize a car's make and model from its silhouette. He suggests that fuel efficiency, safety, environmental needs and mass-market preferences all pushed shapes toward a more uniform appearance.

Mars regrets some of that sameness, though he admits that he does not automatically like every design that breaks away from it. Cowen finds the conspicuous equipment on Waymo vehicles appealing; Mars says driverless cars evoke a recurring personal nightmare, while expressing a favorable view of the technology.

Cowen asks about New Jersey's jughandles, which route drivers rightward to make some left turns. Mars sees an efficiency benefit for drivers who know the roads, but finds inconsistent placement stressful for visitors who must quickly choose the correct lane. Cowen adds that the layout uses land.

On yellow street lighting, Mars says he is unsure of its specific advantage. He favors less glaring, responsive light that takes light pollution and the night sky into account, recalling designers who worked on that problem.

For road markings, Mars values visible distinctions and reflective markers. As his vision changes with age, he says reflective paint and road studs help him see the road. Visibility, rather than appearance alone, is his primary criterion.

Cowen contrasts the attractiveness of some New England towns with Houston's growth. Mars says Houston's approach to land use can facilitate growth but also favors car-oriented development, which he dislikes as the only urban option. His broad characterization of zoning is his own shorthand; the discussion does not examine all of Houston's land-use rules.

Mars acknowledges that easier growth and lower costs appeal to some people, and that different communities may make different choices. Cowen asks whether the US can still build attractive places; Mars says it can, pointing to careful combinations of old and new architecture in London.

Mars describes Chicago's buildings as participating in a conversation across decades, with architectural choices responding to their neighbors. He sees a culture of care in that relationship. For him, beauty can come from local continuity as well as an individual building's design.

Neither guest can immediately name a postwar American suburb they find beautiful in the way older examples can be. Mars suggests distance between buildings and pressure for uniform, cheaper construction can weaken cohesion. This is their aesthetic judgment, not a comprehensive survey of suburbs.

Mars recalls telling Stephen Dubner that some building inefficiency can support local decisions and pay local workers. He thinks people may choose to pay for beauty even when standardization would be more efficient. The balance depends on what a community values.

The Chrysler Building, Mars says, faced criticism when modernist tastes favored less ornament. He loves its decorative references to cars and appreciates that buildings can be reassessed over time. Their reception, he argues, is not fixed at the moment of construction.

Mars enjoys brutalism when it is done well, including London's Barbican. He finds abstract shapes compelling but says concrete can age badly and some buildings feel oppressive. The same broad style can produce spaces he experiences as either inhuman or welcoming.

Asked about green cities, Mars points to Central Park and Golden Gate Park as remarkable public spaces. Cowen asks whether creating a similar park in Paris would displace residents; Mars acknowledges that making such a decision today would involve difficult tradeoffs, while emphasizing the value of gathering places.

On Jane Jacobs, Mars praises her bottom-up observations of neighborhoods and street life. He resists an extreme reading that leaves no room for top-down planning, arguing that functioning cities need both approaches to listen to each other. He describes possible preservationist consequences as his interpretation, not as a claim Jacobs explicitly wrote them.

Cowen asks about e-bikes and their lanes. Mars is unsure what Jacobs would have thought, but supports streets serving several modes rather than cars alone. He likes cars in some settings while arguing that cities benefit from alternative ways to move.

Discussing Tokyo, Mars praises the ability to get around by public transport. Where networks are patchy, he suggests buses and e-bikes can provide comparatively inexpensive connections. The exchange is about their design preferences, not a measured comparison of every Japanese transport mode.

Cowen raises the possibility that global coffee shops and other spaces are becoming placeless. Mars agrees corporate styles can flatten local differences, but says careful travelers can still notice small variations, even on the menu of a familiar chain.

Has the iPhone become boring, or have users simply become accustomed to it? Mars thinks tastes shift as familiarity grows. He recalls the appeal of sleek forms and then the later desire for a button or a different shape; he also remembers choosing a Motorola Razr for its appearance.

Cowen prefers a more robust phone even if that makes it less sleek, and Mars agrees. Mars notes that the phone has become a pocket computer with many functions, while some users seek simpler devices where calling matters most. He leaves open whether devices may split into different forms again.

Asked for the ugliest country he has visited, Mars declines to name a whole country. He describes difficulty walking in parts of Bali where motorcycles, traffic and open gutters demanded constant attention, while also praising other parts of the place. Cowen gives a negative personal assessment of Riyadh.

Mars likes the usability of Australian currency, including different sizes and colors and the inclusion of artists and other figures. He sees a missed opportunity in US notes' narrower selection of subjects. Cowen, by contrast, enjoys the dollar's unusual symbols and visual character.

Mars grants that US currency has charm but argues its continuity limits opportunities to improve accessibility and materials. Cowen jokingly interprets its similar-looking denominations as a confident expectation that users will adapt. These are interpretations of design, not a claim that all currencies are pegged to the dollar.

Should power lines go underground? Mars sees potential safety and aesthetic benefits, including reducing some fire risks, but recognizes the cost and slower construction involved. He frames it as a balance rather than a single solution for every place.

Cowen asks how to signal unusually large speed bumps. Mars says signs and road markings can help, but suggests uncertainty itself may make drivers slow down. Cowen counters that repeated exaggerated warnings can lose credibility; they disagree about how people respond.

How can a society warn people about radioactive waste thousands of years in the future? Mars explains that future readers may not share today's language, symbols or even assumptions about reading a sequence of pictures. Researchers have considered unconventional cultural signals, including stories and imagined biological markers.

Mars notes another problem: warnings can make a protected site look as though it contains treasure, motivating people to enter. The discussion illustrates the difficulty of designing a message across millennia; speculative ideas such as glowing cats are not presented as an implemented safety system.

The guests then debate advisory speeds on highway ramps. Mars discusses how road design and signs shape drivers' perception at speed, while Cowen questions whether deliberately conservative numbers reduce trust. Their personal rules of thumb are not instructions for safe driving.

Cowen turns to Mars's well-known talk on city flags and asks why he discourages lettering. Mars says a flag is seen from both sides while moving, making text hard to read. Cowen challenges whether outside visitors notice city flags at all.

Mars argues that an attractive, usable flag can become a civic symbol people choose to display, citing Chicago. He stresses that design principles are tools rather than a police code: if a busy flag with words creates pride and works for its community, he is happy for it to do so.

He admires exceptions, including Maryland's intricate flag and Brazil's flag with its motto. His aim is to encourage communities to consider flags as shared objects worth designing and displaying, not to demand absolute obedience to a single rule.

Cowen asks about Pocatello, Idaho, whose former flag Mars had publicly criticized. Mars says the city took the attention in good spirit and used it as motivation to redesign. He recalls a local leader saying that being clearly last helped prompt a conversation and a fun process of choosing something new.

Mars estimates that hundreds of US municipal flags have been redesigned since his talk. He values the discussion even when a community decides to retain its old design: the point is people considering what represents their place. He contrasts a city's enduring identity with sports teams that may move away.

Mars describes turning a small utility closet in his home into a recording studio. He and his stepdaughter installed sound-dampening material, and he works at a standing desk. The open-plan house still transmits household sounds, so the studio is well suited to him without being acoustically perfect.

Cowen asks why an audio-only show works for visual subjects. Mars says an image can trigger immediate aesthetic preferences; a story can first explain a building's purpose and context. When listeners later see it, they may notice functional merits that an initial glance would have missed.

Asked about an unusual work habit, Mars describes enjoying the changing work of a producer: editing, writing, solving the next episode, funding the show and helping colleagues do their best work. He treats getting a show on air as a whole problem, with no part too small for attention.

Mars also tries to lead with kindness. He describes a culture in which colleagues feel supported and can bring their personalities to a shared creative project. Cowen thanks him, and Mars closes by saying the conversation has been fun.