Travel Time and Sustainable Travel Behaviour

1. Travel Time and Sustainable Travel Behaviour David Metz Centre for Transport Studies University College London

2. National Travel Survey • 7-day travel diaries recording personal travel • Annual sample of 20,000 • Since 1972 • Longest time series; high quality • Excludes international air travel • Measures ‘daily travel’

3. Travel time, hours per person per year

4. Distance & journeys per person per year

5. Trips by age

6. Trips (pppy) according to car ownership

7. Trips (pppy) according to income

8. Main journey purpose, trips pppy

9. Travel spend (% of household spend)

10. Travel time: an hour a day Journeys: 1000 a year Journey purposes: unchanged Spend: 16% of household spend Incomes: double over 30 years Technology: incremental improvement + decarbonisation Car ownership increase? Distance travelled? Business-as-usual scenario

11. Personal mobility: miles pppy

12. Delays for slowest 10% of journeys on Strategic Road Network

13. Hypothesis: daily travel demand has saturated • Access and choice increase with square of speed • Value of additional choice characterised by diminishing marginal utility • Prediction: sufficient choice experienced through mobility

14. FIGURE 3.9Proportion of the UK urban population with a choice of one, two, three or fourgrocery stores each with a different fascia and larger than 1,400 sq metres Source: CACI Limited analysis of parties’ data submissions – from Competition Commission: The supply of groceries in the UK market investigation report, May 2008.

15. Choice of schools and hospitals • Over 80% of pupils have at least 3 secondary schools within 5km of home • Secondary schools have 6 others within 10min drive time • 40% of population have up to 2 hospitals within 15min drive time; 90% within 60min

16. Business-as-usual scenario (2) • Stable behaviour in aggregate: • 7100 miles • 1000 trips • 380 hours a year on average • But road traffic continues to grow….

17. Growth 1996-2006 • Distance pppy (NTS) 0.2% pa • Vehicle km 1.3% • Cars 2.6% • Population 0.4% • Traffic growth due mainly to increase in car ownership • Distance per incremental car = ½ average

18. Sustainable travel • Stable personal travel – travel demand saturated. • Some car ownership increase by ‘late adopters’, as car use approaches saturation. Some mode switch to cars. • Decarbonise transport system. • Manage congestion.

19. Transport policy and operations • Interventions which have the effect of increasing speed lead to increased access • Interventions which have the effect of reducing speed tend to reduce access and choice • ‘Smart choices’ tend to involve speed reduction • Decarbonisation will need to rely mainly on technology

20. Managing congestion • Can’t build our way out of congestion • Road pricing redistributes road space in favour of those who can afford to pay • Improved access for payers (induced traffic) • Reduced access and choice for non-payers • Likely to be unpopular • Main problem is journey time uncertainty

21. Conventional transport economics • Main benefit is ‘travel time saving’ • Underestimates ‘induced traffic’…. • ….and carbon, accidents and other detriments • Travel a ‘derived demand’ • Agglomeration benefits • Modelling assumes minimisation of ‘generalised costs’ • Neglects behavioural economics

22. References • The Myth of Travel Time Saving, Transport Reviews 28(3),321-336, 2008 • Responses to ‘Myth’ in November issue • The Limits to Travel, Earthscan, 2008 • www.limitstotravel.org.uk • National road pricing: a critique and an alternative, Proc Inst Civil Eng: Transport 161(TR3), 167-174, 2008 • Sustainable Travel Behaviour, UTSG January 2009 • Papers from david.metz@transport.ucl.ac.uk