1. TASK 6: COHORT ANALYSIS OF TRAVEL BEHAVIOR Michael Iacono Technical Advisory Panel meeting September 30, 2014

2. What is a cohort? “A ‘cohort’ is defined as a group with fixed membership, individuals of which can be identified as they show up in surveys. The most obvious example is an age cohort, (e.g. all males born between 1945 and 1950).” Source: Deaton 1985

3. Cohort Dynamics Time = 1980Time = 2010Time = 2000Time = 1990 Age = 18-24 Age = 25-34 Age = 35-44 Age = 45-54 Time

4. Components of Cohorts Cohort Analysis Age effect Period effectCohort effect

5. Car Ownership Cohorts

6. Evidence of Declining Travel

7. An Application: Trip Rates Trend toward declining travel Several possible causes –Higher fuel prices –Recession effects –Declining household size –Demographic shifts “Millennial generation”

8. Trip Generation Model Adult person-trip rates a function of –Household attributes –Personal attributes –Economic and location factors –Demographic structure Birth year cohorts Age effects Period effect (2010)

9. Findings Household attributes dominate Demographic effects significant –Age effects –Cohort effects all highly significant –Large “period” effect “Millennials” had a higher trip rate

10. Future Directions Further refine model Apply to car ownership Further investigation of –Residential location –Millennial behavior –Mode dynamics