Travel Behavior Definitions

# Accessiblity

Accessibility is the ability for individuals to reach destinations where they can accomplish their daily activities. Locations with good accessiblity enable people to make many kinds of trips easily.

# Induced Demand

Basic economics teaches that when supply of a good increases, demand for the good will increase as well. Transportation facilities are often expanded with the hope that speeds will be increased along the corridor. However, some demand may be induced by adding capacity; this demand may have been suppressed by slow speeds. The induced travel demand that comes from improved facilities may increase throughput, but congestion may still occur and result in the same speeds as before the improvement. More businesses and households may choose to locate in order to use the improved facility, further increasing demand beyond the existing demand land use prior to upgrade.

# Travel Time Budgets

A travel time budget is the concept that, similarly to money budgets, people have fixed time allotments in their day for travel. Some researchers have hypothesized that travel time budgets are fixed across different time and cultures, but this has largely been debunked [1]

# Value of Time

A value of time is the value that individuals place on a unit of time. For example, someone might be willing to pay a $10 toll to save one hour of travel time. This is an important consideration in travel behavior models. Different population groups are likely to have different values of time.

# References

  1. Mokhtarian, P. L., & Chen, C. (2004). TTB or not TTB, that is the question: a review and analysis of the empirical literature on travel time (and money) budgets. Transportation Research Part A: Policy and Practice, 38(9-10), 643-675. (opens new window) ↩︎

This site uses cookies to learn which topics interest our readers.