1. Marron Institute of Urban Management,
American Dream Coalition Arlington, August 6 , 2017, The Transportation-Land Use Connection: Myths and reality
By Alain Bertaud
Marron Institute of Urban Management,
New York University

2. Labor markets and speed of transport
Densities, trip patterns and transport modes
Commuting time and densities
Mega cities and the new Chinese city clusters

3. 1. Labor markets and speed of transport
Reminder: why large cities exist
large urban labor markets are more productive than smaller ones
labor markets function better when
workers can select their job among all the jobs offered within a metropolitan area, and
firms can select workers among all the workers available within a metropolitan area.

4. it follows that :
The size of an urban labor force indicates only the potential productivity of this labor force. Deficient transport, or rigid labor laws could greatly decrease its potential productivity
Maximizing the size of an urban labor market would require a commuting time of less than one hour one way from any location to any other within a metropolitan area
Increasing speed of door to door commuting is therefore the key to urban productivity

5. 2. Densities, trip patterns and transport modes
Densities are determined by markets not by planners design
Within a metropolitan area one can observe large densities variations
There are no “good densities” or “bad densities”
Densities in middle and high income countries reflect consumer choices and have a strong cultural component

9. Densities variations within cities reflect market forces not planners’ design

10. Neighborhood densities combined with % of land dedicated to roads define the area of road per person, and therefore largely determine the dominant mode of transport

11. Road area per person in various neighborhoods of some cities across the world

12. Transit is the dominant transport mode in high density areas
Transit is the dominant transport mode in high density areas. Individual transport is the most efficient in low density areas
Clever planners cannot “design” land use to minimize commuting time without contradicting the functioning of labor markets
Planners cannot “design” densities to favor a preferred transport mode without contradicting the operation of both the land and labor markets (compact cities, containment, etc.)

13. Trip patterns: real and imagined

14. The trend is toward increased suburbanization of jobs and residences, even in cities with very dense centers like Paris and Seoul

15. The suburbanization of Seoul and Paris shown at the same scale (Seoul 25 million people, Paris 12 million)

16. Even in metropolitan area like Paris, with an elaborate transit system, the majority of trips are made by cars from suburb to suburb

17. Seoul suburbanization trend: population and jobs are dispersing

18. Atlanta - Spatial distribution of additional population between 1990 and 1999

19. Atlanta - Spatial distribution of additional jobs between 1990 and 1999

20. 3. Commuting time, transport modes and densities

21. High density cities do not have a shorter commuting time than low density cities,
ceteris paribus

22. Beijing subway: Even most modern subways face congestion (seldom measured)
Source: Beijing Transportation Research Center (2015)

23. 4. Mega cities and Chinese city clusters
The Chinese government has recently changed its urbanization strategy. It is now advocating the development of city clusters aiming at integrating the labor force of clusters of cities with aggregated populations from 50 to 110 million people. The transport system that would allow this very large labor markets to function does not exist yet However, the clusters themselves already exist, but are still fragmented as labor markets

24. The Pearl River Delta urban cluster: 65 million people!

25. Transport patterns in a large city cluster

26. Reference to Atlanta paper
Bertaud, Alain, "Clearing the air in Atlanta: transit and smart growth or conventional economics?," Journal of Urban Economics, Elsevier, vol. 54(3), pages , November.