Estimating distance decay for the national propensity to cycle tool

Estimating distance decay: for the National Propensity to Cycle Tool NPCT Robin Lovelace, University of Leeds.. Discovering distance decay... Distance decay in active travel... Distance

Estimating distance decay:

for the National Propensity to Cycle Tool (NPCT)

Robin Lovelace, University of Leeds

Talk at the Institute for Transport Studies (ITS)

speakerdeck.com/robinlovelace

I What is distance decay?

Discovering distance decay

Distance of trip != distance/yr

Distance decay in active travel

Distance decay: the formula

p = f(d)

Euclidean or route distance?

Distance decay in the literature

Source: Lovelace et al., forthecoming.

Tested functional forms

Source: Martínez and Viegas (2013)

DD functional forms

Exponential vs cubic vs linear

Some real data

Source: Lovelace et al (forthcoming)

Linear model to the data

Cubic polynomial models

Log-square-root model

II Why distance decay?

Source: NPCT modelOutput (Leeds)

Distance decay in everyday life

Distance and energy use

Distance and mode dependence (Sheffield)

Distance and mode dependence (England)

Energy and travel mode

III The uses of distance decay

Uses of dd: a few ideas

● If we're to transition away from fossil fuels, we must use modes that are less energy intensive

● Distance decay for sustainable travel modes

can tell us what future travel patterns must look like

● Characterising travel systems

● Especially relevant for active travel

● The National Propensity to Cycle Tool (NPCT)

'Spatial

interaction

models'

DD to characterise travel systems

Modelling travel

IV Wider context of distance decay

Resulting report: national benefits

Benefits of cycling nationwide

Webtag estimates of benefit:cost

https://www.gov.uk/government/publications/webtag-tag-overview

An open source policy planning tool

(+ live demo!)

DD in the NPCT

Further work on distance decay

● The distance-decay of road traffic incidents?

● Its use to estimate non-work travel?

● Verification of dd parameters using Big Data

Key references

● Iacono, M., Krizek, K J., & El-Geneidy, A (2010) Measuring non-motorized

accessibility: issues, alternatives, and execution Journal of Transport Geography, 18(1), 133–140 doi:10.1016/j.jtrangeo.2009.02.002

● Lovelace, R., Clarke, M., Cross, P., & Birkin, M (n.d.) Verification of big data for estimating retail flows: a comparison of three sources against model results