Provide reliable travel time information to increase user satisfaction with ITS applications.
A retrospective of what's been learned since the first ITS Strategic Plan developed in 1992.
Made Public Date
04/19/2006

146

United States
TwitterLinkedInFacebook
Identifier
2006-00212

What We Know Now That We Wish We Knew Then About Intelligent Transportation Systems: A Retrospective on the 1992 Strategic Plan

Background

From September 1991 until June 1992, a core writing team worked on what was the first intelligent transportation systems (ITS) strategic plan in the United States. It defined the ITS program at a national scale in a way that has been characterized as seminal. The plan, by most accounts, served as the blueprint for the early development of ITS in the United Sates and as the basis for subsequent plans produced by ITS America, the Federal Government, various states, and a number of private-sector organizations.

The article, What We Know Now That We Wish We Knew Then About Intelligent Transportation Systems: A Retrospective on the 1992 Strategic Plan, published in 2004, contrasts the 1992 plan with reality 11 years later. Areas discussed in this article include advanced traveler information systems, advanced transportation management systems, reliability, getting the ITS program off the ground in the early 1990s, strategic use of information, automated network management, electronic toll collection, congestion pricing, architecture, commercial vehicle operations, advanced public transportation systems, and regions. ITS is compared with the Interstate system, and a discussion covers both the reauthorization of the Transportation Efficiency Act for the 21st Century and the knowledge that has been gained through this retrospective about ITS-related issues on that reauthorization.

Lessons Learned

In this article, with the changing of the world over the past 11 years and the benefit of hindsight, there were issues not fully understood about ITS that are better understood today. One of the topics discussed in the retrospective review of anticipated versus actual ITS benefits is the importance of providing reliable travel time information to increase user satisfaction with ITS applications.

  • Emphasize improved travel times for key economic benefit and reliability: In the strategic planning exercise of 1991 and 1992, the benefits in improved travel times to drivers were emphasized as a key economic benefit of ITS. While this is true, it overlooked the importance of reliability to the highway traveler. Reliability is a measure of the variability in travel time between two points. For example, on Monday it may be a quick half-hour trip from origin to destination, but on Tuesday an accident, storm, or construction may cause that same trip to take twice that time. If travelers are risk averse about being late, they must build additional time above the quick travel time into their time budget. Often it is wasted time in the sense that one arrives at the destination earlier than intended. But it is a price travelers may be willing to pay to avoid, being late.
  • Provide reliable travel time information: It turned out that a greater degree of reliability available through real-time information about trip times proved to be more important than improvements in average travel time. This is a phenomenon that has been well understood for decades in freight transportation. The trucking industry has won considerable traffic from the rail industry, even while charging premium rates, because it provides more reliable trip times than railroads do. This succeeds because unreliability generates additional inventory costs for the customer. However, the understanding of the importance of reliability for highway travelers, for whom time management is critical, is relatively recent.
  • Produce better time management among travelers by providing reliable travel times: Indeed, it now appears that actual highway travel-time savings are often ephemeral or rather small. There is little empirical evidence to show that small improvements in average travel time are economically meaningful. When people get more reliable trips by receiving information about expected travel time in real time before the trip, some researchers suggest that they end up unconsciously converting that information into (often nonexistent) travel-time savings in their minds. When they receive real-time information about a trip that is about to be on the right-hand tail of the travel time distribution (or even the left-hand tail), what they have actually accomplished is better time management.


This lesson indicates that originally, the anticipated benefits in improved travel times to drivers were emphasized as a key economic benefit of ITS technology deployment. Now, with a retrospective review of those original assumptions, that benefit proves to be less important than originally expected. Instead, improved reliability available through real-time information about today’s trip time is proving to be more important than improvements in average travel time. The lesson highlights the importance of reviewing the original assumptions of ITS benefits with the actual post-deployment experience, for the future promotion of ITS technology.

What We Know Now That We Wish We Knew Then About Intelligent Transportation Systems: A Retrospective on the 1992 Strategic Plan

What We Know Now That We Wish We Knew Then About Intelligent Transportation Systems: A Retrospective on the 1992 Strategic Plan
Publication Sort Date
10/01/2004
Author
Joseph M. Sussman
Publisher
Transportation Research Record: Journal of the Transportation Research Board

(Our website has many links to other organizations. While we offer these electronic linkages for your convenience in accessing transportation-related information, please be aware that when you exit our website, the privacy and accessibility policies stated on our website may not be the same as that on other websites.)

Application Areas

Focus Areas Taxonomy: