Collecting and Analyzing Stakeholder Feedback for Signing At Complex Interchanges

CHAPTER 1. INTRODUCTION

BACKGROUND

Recent research in complex interchanges investigated driver expectations and signing at complex interchanges.^(1,2) The results from these efforts indicated that complex interchanges pose significant challenges to most drivers, and that many of these problems arise from basic human factors issues related to various aspects of interchanges. For example, one important design issue identified was that the perceptual grouping of information elements on guide signs had clear and systematic effects on how drivers interpret and use sign information, and moreover, that the inappropriate application of perceptual grouping led to incorrect driver assumptions about lane destinations. This is a problem from a sign design perspective because these perceptual factors are a source of "uncontrolled" variability in terms of how drivers respond to guide signs. Fortunately, these basic perceptual factors, in addition to other human factors issues, can be investigated using empirical data collection methods. They also have the potential to lead to useful design guidance for promoting the consistent and effective implementation of good practices related to perceptual elements of guide signs.

One limitation of the work conducted in the driver expectations study is that the research was conducted only from a driver's perspective. This was necessary in order to first establish that the human factors concerns represent real and systematic problems. However, before continuing with additional research into these issues, it is an opportune time to consult with roadway engineers and other stakeholders to identify how they can best be served by new research and design guidance about human factors and complex interchanges. Specifically, it is important to know what their constraints are regarding design options. This is critical information because it is important to focus subsequent research on aspects that can be practically implemented. Furthermore, consulting with the stakeholders, who will be the end-users of the design information that this research will produce, is a useful way to gain an understanding of their design process, issues they must consider, trade-offs they make, etc. This information is also invaluable for identifying research questions that stakeholders will find useful and will be able to apply to their specific design problems. All of these aspects were considered during this project.

PROJECT OBJECTIVES

The objectives of this project were as follows:

• To work with roadway engineers and other stakeholders to identify design constraints applicable to signing for complex interchanges.
• To identify useful topics for future research on complex interchanges that might yield findings that can address the design issues identified by stakeholders.

PROJECT OVERVIEW

This project mainly consisted of two stakeholder activities to gather feedback about complex interchanges.

The first activity was stakeholder interviews. These were conducted to collect qualitative data from stakeholders about the following topics:

• Stakeholders' conception of complex interchanges, and experiences with complex interchanges in their area.
• Human factors issues and driver considerations that stakeholders have had to address at complex interchanges.
• Stakeholders' thoughts about human factors research needs that can be used to identify candidate topics for future research plans.

Following the identification of the research needs, a follow-up survey was also used to gather the opinions of a broader group of stakeholders to prioritize future research topics.

REPORT OVERVIEW

This report provides a description of the methods, results, and conclusions from the stakeholder feedback activities conducted in this project. The body of this report contains the following topic sections:

• Methods. This section reviews the methods used to recruit stakeholders, collect their feedback on concepts related to complex interchanges (e.g., signs, markings, roadway geometry, etc.), gather their opinions on the priority level of the different research ideas, and analyze the data.
• Results. This section describes the results of both the stakeholder interviews and the follow-up survey.
• Conclusions. This section discusses ideas for future research and other conclusions drawn from the results.
• Appendices
  • Appendix A: Flyer used for recruitment efforts.
  • Appendix B: Visual presentation of interchange signing examples.
  • Appendix C: Interview guide used during the interviews.
  • Appendix D: Follow-up survey questions.