I live in San Francisco's Nob Hill area, and got rid of my last car 19 years ago because all the known world is within walking, biking, or transit distance. Here are some statistics comparing higher and lower density urban areas and how that density affects transport choices and resource use:
| Manhattan | San Francisco | San Ramon (post-'30s suburb) | |
|---|---|---|---|
| Density (households/acre) | 200 | 100 | 3.2 |
| Mass transit (veh/hr nearby) | very high | 90 | 1 |
| Shopping (5 within 1/4 mi) | all | all | none |
| Ped amenities | high | high | low |
| Autos/capita | .12 | .28 | .79 |
| Ann. veh. miles/capita | 1,145 | 2,759 | 10,591 |
| Annual household auto costs | $800 | $1,900 | $8,200 |
From 2 households/acre up, each doubling of density reduces driving 25--30%; from 10 hh/acre up, each doubling reduces driving 40%.
(Holtzclaw,
1994)
| A subway line | accommodates as many travelers as | 35 | freeway lanes |
|---|---|---|---|
| Light rail or bus line | " | 15 | " |
| Lane of walkers | " | 5 | " |
| Bicycle lane | " | 2 | " |
| Suburban street lane | " | 0.3 | " |
And there's more to it than just the driving:
Suburban homes (compared to a typical Nob Hill, S.F., apartment) use:
(Phillips & Gnaizda, CoEvolution Quarterly, Summer 1980)
- 5x the copper pipe
- 35x the land
- 15x the roadway
- 4x the lumber
- 70x as much water
- 5x as much heating
Some features of pedestrian- and transit-friendly neighborhoods:
- fine-grain street grid--small blocks with through pedestrian routes
- secure bike parking
- wide continuous sidewalks with trees, bus shelters, seating, and fountains
- buildings near the sidewalks, not set back behind parking or broad lawns
- traffic calming--narrow roads, frequent vehicle stops, prominent crosswalks
My neighborhood is one of the most densely populated American areas west of the Hudson River. I have over 700 restaurants within an easy, interesting 1-mile walk, and even more markets, as well as coffee houses, sidewalk cafes, and a wealth of interesting neighbors. Who could not love living where neighbors meet on the sidewalk and in corner markets, developing a sense of community and security because they look out for each other?
John Holtzclaw studies the interactions between transportation, land use, air quality, energy consumption, and society, primarily for environmental groups, and is chair of the Sierra Club's transportation committee.