Climate & Environment

Vehicle Miles Traveled (VMT)

Meaning statusEstablishedSource recordDirect document linkedWhy these are different

Definition

Vehicle miles traveled is the aggregate distance driven by vehicles in a system over a period — the fundamental measure of road transport activity and a first-order determinant of emissions, congestion, crashes and road wear. Policy analysis distinguishes VMT growth from efficiency: the US experience showed fuel economy gains largely eaten by VMT growth, and California's SB 743 made VMT reduction itself (rather than congestion) the environmental test of development projects.

References

www.itf-oecd.orgBulk import source

This reference provides supporting context for how “Vehicle Miles Traveled (VMT)” is defined and used.

opr.ca.govBulk import source

Source imported for editorial provenance.

Overview

How it is used

The metric structures transport planning and modelling, emissions forecasting, development review (VMT-based impact assessment), and road pricing policy.

Why it matters

Emissions equal miles times intensity; technology fixes intensity, but someone must bend the miles — that is VMT policy.