By Dom Nozzi
Those who work in the fields of town planning and transportation are well aware of the overwhelming evidence that there are a great many significant benefits of higher density development patterns. Tragically, nearly all Americans believe higher densities destroy neighborhoods and overall quality of life.
Why this disconnect?
Because nearly all Americans are utterly dependent on car travel, and higher densities make car travel much more costly and much more inconvenient.
Given this, it is clear that car-dependent Americans have a vested interest in fighting against efforts to improve community quality of life. This helps explain why so many community problems persist throughout the nation.
In my 40 years of academic work in town and transportation planning, I have found that research studies show repeatedly and clearly that higher-density community and neighborhood development patterns provide the following benefits:
More affordable housing. This is due to smaller house size, the smaller amounts of land owned, and the ability of the household to survive with a smaller number of (extremely expensive) household cars. This is because more compact development patterns allow people to engage in many daily tasks without needing to travel by car.
Less per capita car travel. This reduces per capita air emissions.
More physically fit community. With higher per capita levels of walking, bicycling, and transit use, residents of higher-density communities tend to be much more physically fit and less obese. Higher-density places promote social capital, and higher social capital is shown by studies to promote happiness, health, and longevity.
More financially sound households. A century ago, transportation was about 1 to 2 percent of household costs. Today it is about 23 percent and rising. The average annual cost of each car owned by a household is approximately $10,000. Higher-density neighborhoods substantially reduce the need for car ownership, car use, and overall household transportation costs. In addition, higher-density communities provide households with more job opportunities.
Lower startup costs. As Jane Jacobs noted several decades ago, higher-density town centers provide significantly lower capital startup costs for a small business. For example, it is much more financially viable for an individual to sell cooked food from a cart on a dense street corner than for an individual to buy or lease a restaurant building to sell cooked food.
More neighborhood-based (and smaller) retail. Only higher densities make smaller, neighborhood-based, locally-owned shops financially feasible. Lower-density communities tend to only be able to financially support franchise stores or large-format retail stores that draw customers from a regional consumer-shed.
More neighborly. Higher-density neighborhoods promote sociability. Lower-density neighborhoods promote isolation and suspicion.
Slower speed. Healthy cities are slower in speed, as slower speeds promote retail and residential health. And significantly reduces traffic injuries and deaths. These benefits explain why there is a global movement o create “slow cities.”
More abundant and diverse choices. Higher-density neighborhoods inevitably create much more in the way of choices for restaurants, other types of retail and specialty goods, and culture.
More innovation and creativity. Many studies show that higher-density cities are significantly more innovative and creative than lower-density cities. Higher-density cities attract more talented, skilled people.
More exchange. The main reason cities exist is to promote the exchange of goods, services, ideas, and sociability. Higher densities substantially increase the efficiency and amount of exchange.
More productive workforce. Higher-density cities not only attract more talented workers – which in itself promotes productivity – but also enhances productivity by reducing transportation costs in creating products or providing services.
More walking, bicycling, and transit use. Higher densities induce mixed-use development patterns, which substantially reduces trip distances. Relatively short travel distances to destinations is by far the most powerful way to increase walking, bicycling, and transit use.
Higher quality transit. Higher-density leads to higher transit ridership, which leads to better, more widespread, and more frequent transit service.
More housing choices. Lower-densities tend to deliver very limited housing choice. Nearly all of the housing consists of large single-family homes on large lots of land. Higher-density neighborhoods can provide townhouses, apartments, accessory units, co-ops, and live-work spaces.
More fiscal health for local government. Lower-density development, as shown by strongtowns.org, is a fiscal parasite because it fails to generate anywhere near the tax revenue needed to pay for its significant impacts (mostly road work) on the community. And minimizes per capita expenditures for infrastructure.
More security from crime. Higher densities promote citizen surveillance (often called “eyes on the street”). Higher densities lead to more regular use of sidewalks and observing the outside through house windows greatly contributes to our looking out for our collective security. Since criminals tend to rely on not being seen, this citizen surveillance greatly reduces crime. Many compact neighborhoods are now called “911” neighborhoods, as compactness increases the chance someone will spot an emergency and call 911.
More travel independence for those unable to drive a car. In a lower-density neighborhood, distances to destinations are far away and require the use of dangerous and high-speed roads. This makes car travel essential for nearly all trips, and those unable to drive (such as seniors, children, and the disabled) therefore lose travel independence. They must rely on others to get around.
More environmentally friendly. If we take, say, 100,000 people, that number of people will consume less environmentally sensitive land, produce far less air and water pollution, consume far less energy, and require less asphalt and concrete when living more compactly (ie, at higher densities). If we take that same 100,000 people and disperse them in lower-density patterns, the result is far higher levels of air and water pollution, far larger amounts of environmentally sensitive land consumed, far higher amounts of energy consumed, and far more asphalt and concrete needed.
Final Thoughts
A big part of the problem with the disconnect between the many benefits of compact development and the high level of citizen opposition to such development is that those who dislike density are thinking about the issue as a motorist and not as a human being. Since cars take up so much space, density is something that often and understandably makes the motorist furiously mad (so mad that the emotion tends to turn off a person’s brain). The idea of added density is seen as a direct threat to their ability to travel unhindered (or unfrustrated) by car.
It threatens the very core of their drivable lifestyle.
Car travel in a dense city is an effective recipe for infuriating a motorist. And again, because of the large space consumption of the car, nearly every trip the motorist takes puts them in a bad mood, as it is highly likely that driving a big metal box will be frustrating – even when densities are low.
Getting around by bicycle (or when I walk or use the bus), I pretty much never notice traffic congestion. In fact, almost every bike ride I take puts me in a better mood.
Some references:
http://www.lgc.org/wordpress/docs/freepub/community_design/reports/density_manual.pdf
https://theconversation.com/higher-density-living-can-make-us-healthier-but-not-on-its-own-34920
https://www.citylab.com/life/2012/11/cities-denser-cores-do-better/3911/
https://www.brookings.edu/articles/demand-for-density-the-functions-of-the-city-in-the-21st-century/
https://www.citylab.com/life/2012/04/why-bigger-cities-are-greener/863/
https://www.britannica.com/topic/urban-sprawl/Costs-of-urban-sprawl
Dom's Plan B Blog 
Hi Dom, could you put a more precise number on the “ideal density” of a city (in terms of thousands of people per km2)? Compared to suburbia, just about every town/city in Europe will seem extremely dense at first, but distances to everyday destinations can still be quite far for the average pedestrian and cyclist, especially once you leave the historic walled town centers. I still think though that the overall public realm and a tight urban grid are the most important things to keep in mind. Density alone doesn’t really seem to have much of an effect if it means we all are supposed to lead an efficient lifestyle in a city with ugly architecture. Regards, Charles
Thanks for reading my blog, Charles, and for your comments. I agree with much of what you say. I don’t believe there are “ideal” numbers of density. I do know that nearly all of the more recent development (since the early part of the 20th century when motor vehicles emerged) tends to be far too low and far too dispersed in density. That is because (oversized) motorized traffic quickly becomes exceptionally frustrating and infuriating when we design compactly for proximity (which makes it practical to walk or bicycle). Shame on us in contemporary decades for building dispersed communities that are impractical for walking or bicycling — places that utterly fail to provide romantic, human-scaled charm. I fully agree about the tight urban grid and public realm. And that we need far more than increased density for better cities. Returning to using timeless architecture rather than modernism is very important. Tragically, I believe we have reached a point of no return concerning the need for compact, human-scaled design conducive to travel choices. It is politically impossible — short of severe economic woes — to use human-scaled, low-speed design in a world where 98 percent of us are trapped in a car-based lifestyle. That 98 percent will understandably fight vigorously against human-scaled, low-speed design because such design is an existential threat to their lifestyles.