literature has shown few, if any, articles discussing the visualization of safety data. Breyer discussed the use of geographic information systems, Global Positioning Systems, and photolog-type tools to visualize, analyze, and catalog crash history and roadside character- istics (6). These types of technologies are much more useful in assist- ing the traffic safety professional with identifying locations (hot spots) where safety improvements can be implemented rather than used as tools to understand the patterns in safety data (6). Yi et al. have discussed the implementation of a networking and visualiza- tion systems approach to crash data analysis in which a collision dia- gram would automatically be constructed on the basis of the types, movement characteristics, and points of impact to eliminate the manual decoding of the crash type, reducing human error (7 ). There are various examples of tools and methods that have been used for the analysis of events and actions leading to crashes involv- ing pedestrians (8). Of note is the Pedestrian and Bicycle Crash Analysis Tool (9). Other approaches involve geographic informa- tion systems and spatial clustering techniques for the identification of locations where pedestrians are involved in crashes (10, 11). With any tool, it is important for it to be useful in identifying prob- lem locations, causal factors, and countermeasures for reducing accidents (12). Although thoughts of Hawaii conjure images of sandy beaches and swaying palm trees, it is also an ideal location for the develop- ment and testing of various tools for traffic safety research. After the safety viewgram and how it is meant to be used are described, an illustrative example that uses driver and pedestrian interactions in Hawaii is presented. The safety viewgram can be used to assess both general situations and specific types of intersections or particular types of drivers and pedestrians or can even be used for the analysis of individual locations. A concluding section provides some further directions and extensions currently under development. THE SAFETY VIEWGRAM One of the challenges to safety research involves capturing the simul- taneous effects of different human, vehicle, roadway, and environ- mental factors. These interactions are complicated by the fact that two or more different agents may be coming together in a motor vehi- cle accident. One way of conceptualizing traffic safety is in terms of the interaction between two different agents who either comply with or violate traffic safety rules. With two different agents, there are four possible states: State 1. Both agents comply with the safety rules. State 2. Agent 1 complies with the safety rules but Agent 2 does not. State 3. Agent 2 complies with the safety rules but Agent 1 does not. State 4. Neither agent complies with the safety rules. Use of Safety Viewgrams to Visualize Driver and Pedestrian Interactions Karl Kim, I. Made Brunner, and Eric Yamashita The purpose of this paper is to describe the development of a tool for visualizing, at a glance, the salient features of the interaction between motorists and pedestrians. Simple, yet robust and flexible, tools are needed to describe and summarize real-world roadway conditions for problem identification and to monitor the progress that has been made toward achieving safety goals. In the study described in this paper, the safety viewgram has been developed to help visualize various types of traffic safety problems. Although this particular tool has been devel- oped by using observational data for pedestrians and drivers in Hawaii, it could be used for other types of safety studies in other locales. After the development and use of this tool are described, a number of differ- ent illustrative examples of how it might be used are provided. Although this is largely a visualization tool, efforts are under way to devise both more rigorous statistical applications and a user-friendly interface for data entry, data manipulation, and presentation of the traffic safety viewgram. Despite the efforts that have been made to improve safety, traffic accidents still claim thousands of lives and injure millions of peo- ple. The problems are related to increased motorization, which has meant that more people are driving, resulting in an increased num- ber of accidents (1, 2). As a consequence, new and improved tools for the investigation of traffic safety problems, for the evaluation of interventions, and for education of the community and decision makers are needed. This paper describes the development and test- ing of a new tool for visualizing traffic safety problems, called a “safety viewgram.” The tool is not meant to replace statistical analysis and modeling. It is meant to be used in conjunction with other tools and techniques for analyzing, classifying, or categorizing safety problems. There is precedent for developing alternative approaches to visu- alizing quantitative data. See, for example, the delightful books by Edward Tufte (3, 4), in which attempts are made to understand numer- ical information through graphical means. Data-mining technologies are used as methods for pattern recognition and for exploratory analy- ses (5). The use of tools for visualization stems from two lines of research. Information visualization research examines data distri- butions, whereas data-mining research focuses on statistical algo- rithms that can be used to find interesting patterns. Still, a means for the visualization of safety data is lacking. An examination of the Department of Urban and Regional Planning, University of Hawaii at Manoa, 2424 Maile Way, No. 107, Honolulu, HI 96822. Corresponding author: K. Kim, karlk@hawaii.edu. Transportation Research Record: Journal of the Transportation Research Board, No. 2002, Transportation Research Board of the National Academies, Washington, D.C., 2007, pp. 72–77. DOI: 10.3141/2002-09 72