Modeling

Unit of Analysis

Ben-Akiva identifies three ways of modeling travel activity:

Source: Ben-Akiva (2008)

Variables of Interest

Some common variables used are:

Abbreviation	Variable	Description
VRH	Vehicle Revenue Hours	Hours traveled while in service
VRM	Vehicle Revenue Miles	Miles traveled while in service
UPT	Unlinked Passenger Trips	Origin-destination pairs

One helpful resource is the Federal Transit Administration's glossary.

Travel costs

Anderson (2013) weights time spent waiting at a higher cost than time in free-flow traffic.