State of the Practice for Traveler Information During Nonrecurring Events

CHAPTER 1. INTRODUCTION

Background and Objectives

Incident-related and other nonrecurring congestion are major contributors to total congestion delays on highways. For example, it has been estimated that roughly half of all delays on freeways in the United States are due to nonrecurring causes.⁽⁷⁾ Types of nonrecurring events may include traffic incidents, severe weather, work zones, emergencies, and sporting events. Devices and media that can be used to convey information about nonrecurring events to travelers may include mobile apps, changeable message signs (CMSs), telephony, websites, radio, and in-vehicle devices that may become part of the connected vehicle ecosystem. It is important to review outcomes from a traveler’s perspective regarding access to, perception of, and need for traveler information surrounding nonrecurring events. It is also essential to take into consideration that in order for information for nonrecurring events to be optimally presented, it must match user needs in both content and media. Examination of the ever-expanding role of the private sector in existing and future real-time advanced traveler information systems (ATISs) were also considered throughout.

The purpose of this task order was to identify and comprehensively review literature and synthesize best practices on efforts to understand travelers’ information needs and related decisionmaking processes within the context of nonrecurring events. The ultimate goal was to find what information will help the traveling public make the most effective and safest travel decisions during nonrecurring events.

This report presents a comprehensive review that is up to date and easily accessible for use with present-day challenges while also being forward-looking for upcoming trends and advances as the landscape of nonrecurring events information evolves. This review emphasizes clarity, relevance, and ease of use for a wide range of potential users. It can be used as a tool to understand how to anticipate and adapt to user needs and decisionmaking processes in a range of nonrecurring event situations. Information about nonrecurring events had traditionally been investigated from the perspective of agency dissemination practices and considered a limited range of situations. The best dissemination practices, however, must also account for the audience and needs of the public.

Methodology

The research effort began with keyword searches of relevant databases with an emphasis on recent information.⁽⁸⁾ To be fully comprehensive, the review also included information gathered from international sources.^{(9 ,10)} Each search included a combination of keywords as well as supplemental keywords used to refine search results. The following five main search categories were created to encompass the key project dimensions, as outlined in the statement of work: (1) core concept, (2) data and technology, (3) location, (4) specific technologies, and (5) supplementary terms. Using these categories, a list of search terms was then compiled and organized appropriately. As an example, the search terms “traveler information” and “incident” were both placed in the core concept category. The following list shows an initial sample set of search terms organized by the five key search categories:

• Core concept: Traveler information, nonrecurring events, decisionmaking, weather, work zone, incident, special event (planned), event, user, and travel time.
  
  
• Data and technology: ATIS, intelligent transportation system (ITS), technology, real time, dissemination, and instrumentation.
  
  
• Location: Pre-trip, en route, and destination.
  
  
• Specific technologies: Connected vehicle, CMS, highway advisory radio (HAR), 511, mobile apps, cell phones, and Global Positioning System (GPS).
  
  
• Supplementary terms: Guidelines, best practices, operations, traffic, congestion, requirements, implementation, and reliability.

Additional search terms were added and adjusted for follow-up searches.

Boolean logic was applied to further define the search. Search terms from the five categories were combined with Boolean operators (AND, OR, etc.) to exclude irrelevant literature and limit results to within the project scope. For example, in an initial search, terms from the core concept, location, data and technology, and specific technologies categories were combined in a way that would return literature containing any of the keywords in any of the categories. Due to search character limits, this Boolean combination can be divided into a series of searches as follows:

• (“nonrecurring event” OR “traveler information” OR “user”) AND (en-route OR pre-trip) AND (“smartphone apps” OR “changeable message sign” OR “radio” OR “511”)*.
  
  
• (“nonrecurring event” OR “traveler information” OR “user”) AND (“intelligent transportation system” OR “ATIS”) AND (“connected vehicle” OR “cell phone”)*.

Note that the asterisk represents a “wildcard” character. In anticipation of these search terms returning thousands of documents, in each case, the first 100 search results were carefully screened. Relevant literature was identified, as defined by the project dimensions and the statement of work. Additionally the following avenues were reviewed:

• Societies and committees: Several societies and committees were reviewed to aid in information gathering and outreach, such as the following:
  
  
  • Transportation Research Board (TRB) (e.g., Regional Transportation Systems Management and Operations Committee and Freeway Operations Committee).
    
    
  • ITS America (e.g., Information Communication Forum).
    
    
  • ITS World Congress.
    
    
  • Institute for Transportation Engineers (ITE) (e.g., Transportation Systems Management and Operations Council and associated committees).
    
    
  • American Association of State Highway and Transportation Officials, including the Subcommittee on Traffic Engineering.
    
    
  • Institute of Electrical and Electronics Engineers.
    
    
  • National Committee on Uniform Traffic Control Devices.
    
    
  • Consumer electronics meetings and relevant committees.
    
    
  • International organizations and committees (e.g., ERTICO ITS Europe is a partnership of around 100 companies and institutions involved in the production of ITSs).
    
    
• Conference proceedings: Conference proceedings were searched because developmental work and practices are often presented there. Conferences conducted by the organizations mentioned in the previous list were a starting point for a search. (Note that helpful conference proceedings are documented throughout the report.)
  
  
• Social networking: It was important to utilize social communities through sites such as LinkedIn®, Facebook®, and online community forums (e.g., ITE Community) to share information among practitioners who are tackling many of the challenging topics regarding traveler information for nonrecurring events.
  
  
• Industry contacts: Informal meetings often aid in providing a view into trends. Industry contacts were established and contacted throughout the research process. The team reached out to traffic management center (TMC) pooled fund study members along with engineers, ITS managers, TMC systems operators at State transportation departments, and other contacts via email and telephone to conduct brief interviews. This allowed the team to leverage contacts from other projects simultaneously.
  
  
• News: News websites, magazines, and trade journals were searched. (Note that helpful websites, magazines, and trade journals are documented throughout the report.)

Once key sources were identified, they were analyzed in terms of the following:

• Range of content and level of detail.
  
  
• Treatment of general principles, techniques, specific parameters, and features that could be applied to the task at hand.
  
  
• Relevance—both technological and practical.
  
  
• Audience/practitioner, including driver needs and desires of content, mode, and timing.
  
  
• Potential for impact on traveler information operations, management, and dissemination.

Organization of Report

The remainder of the report is organized into the following chapters:

• Chapter 2 discusses traveler information needs and decisionmaking processes around nonrecurring events.
  
  
• Chapter 3 provides a brief overview of agencies’ dissemination methods and practices to provide a general impression of the range of available methods, emerging technologies, and trends.
  
  
• Chapter 4 highlights some of the common challenges and issues practitioners face when implementing a traveler information system for nonrecurring events.
  
  
• Chapter 5 presents two brief case studies of successful traveler information for nonrecurring event implementations. The case studies were chosen from the set of implementations briefly discussed in chapter 2.
  
  
• Chapter 6 presents lessons learned and conclusions.
  
  
• Appendix A provides example messages for a range of events as well as information regarding message timing in respect to the event and delivery method.
  
  
• Appendix B offers a sampling of mobile apps from State transportation departments and other regional sources.