Associating

David Levinson

Questions

• How do people find jobs?

• Does land use pattern matter?

• How should JH Balance be measured?

• Jobs Housing Balance does it do anything?

• Does the market create JH balance on its own?

• Is JH Balance good policy?

Policy Issue: Should land use be regulated to change

travel behavior?

Justifications:• Congestion• Air Pollution• Energy Use• Quality of Life• Equity/Spatial Mismatch

Counter-Argument• Individual Rights• Transportation (Land Use)

Already Subsidized• Government Intervention

Counter-Productive• Congestion Acceptable

(Min. Req. Commute)• Energy Use a Market Issue• There is no “Spatial

Mismatch”

Question: Which Scenario Produces More Traffic on the

links between the cities?

100Jobs

100Workers

Scenario A - Unbalanced

50 Jobs50 Workers

50 Jobs50 Workers

Scenario B - Balanced

Answer:

• Obviously Scenario A does. In Scenario B, at least some of the workers will work in the same town in which they live.

• At metropolitan or global level, jobs and houses are inevitably balanced.

• It is at the sub-metropolitan geography that the issue arises.

Measuring Jobs/Housing Balance: Issues

• The simplest measure is jobs housing balance in a town. However, some areas (downtown) clearly have a surplus of jobs and others a surplus of workers. Because there are economies of agglomeration at some level, it does not necessarily make sense to want the jobs to employed residents ratio equal 1 in every city or town.

Jobs Accessibility to Housing Accessibility ratio

• Jobs Accessibility to Housing Accessibility ratios were analyzed for suburban Washington DC. Individuals who lived in areas with high jobs access had shorter commutes, those who lived in areas with lots of competing workers had longer commutes. The advantage of this measure is that it includes all of a region's houses and jobs, measured at a point, properly weighted by their effectiveness.

• Recall that accessibility is a continuous variable which is measured by counting the number of activities (e.g. jobs) available at a given distance from an origin (e.g. the home), and discounting that number by the intervening travel time.

Wasteful Commute

• What is the minimum required commute, assuming that we can move all residents to the best possible houses?

• Waste = Actual commute - Minimum Required Commute.

Independence Index

• Independence Index = internal work trips / total work trips

Is this balanced?

50 Jobs 50 Workers

Scenario C - Balanced?

1000 Jobs 0 Workers

Discussion Questions:

• Is self containment good? • Should Downtown Minneapolis be balanced? • Should the city of Minneapolis be balanced? • Hennepin County? • The Seven County Region? • What deviation from balance is reasonable?

What is the effect of jobs-housing balance on

transit?

100Jobs

100Workers

Scenario A - Line Balanced, Stations Unbalanced -Results in Deadheading

Eveningdeadhead

Morningdeadhead

While:

50 Jobs50 Workers

50 Jobs50 Workers

Scenario B - Balanced Stations and Lines - Efficient

Even flowacross thepeaks

But:

100 Jobs 100 Jobs

NoCommuteTraffic at all

Scenario C - Line Unbalanced - No Traffic

Jobs Housing Balance and Transit:

• Hypothesis: At a minimum, the area around the stations on a line should be balanced, preferably the area around each station.

How to correct imbalance?

• Let market forces run, • Remove intervention - eliminate regulations

(zoning, minimum lot size regulations, growth management) that limit ability to efficiently balance houses and jobs

• Pricing - Charge more to develop in imbalanced area

• Intervention - Construct additional houses in urban areas, jobs in job-poor area

Density of Some US Cities (persons per square mile)

• City of Minneapolis = 6710 ppsm• City of St. Paul = 5156 • City of San Francisco 15502• City of Boston = 11720• City of Portland, Oregon = 3515 (note very large area)• City of Chicago = 12257• City of Los Angeles = 7434• City of Washington DC = 7693 (in 1998)• City of New York = 23697

Conclusions: Density or Balance?

• Which matters more?• For trip generation - density

– More people = more trips

• For trip distribution - balance– Less balance means longer trips

• For mode choice - density– Transit requires critical mass