Advances in technology in both data collection and management offer many cost-effective opportunities to overcome current issues related to the collection and management of safety data. Sensitivity to designers’ safety-related data needs in data-collection programs is part of the solution. Organizational strategies are recommended, designed to change from "business as usual," and upgrade the importance of safety information.
The role of technology
Despite recent technological advances, few agencies employ anywhere near the full range of technologies that could optimize their use of safety data. Technologies can be applied to data collection, management, and communications, including sharing databases, user interfaces, analytical tools, and decision support. With the advent of computer-aided engineering (CAE), highway agencies now have the ability to build and maintain detailed inventories of their system by direct reference to computer files of as-designed roadways. Of the 33 states contacted in a survey, approximately one half (although not always the same states) use portable computers, global positioning equipment, instrumented vehicles, and geographic information system-based data as their means of assisting with data collection. Less than one third used optical reading for forms and distributed databases. Linkage of crash reports and medical data, use of modeling tools or decision support systems, is also done on a limited basis. Overall, agencies still are not taking full advantage of the powerful computer-aided tools now available.
Application of technologies offers the opportunity for agencies to improve the quality of data with less effort or cost than currently being expended. Traffic volume data gathering, for example, can take advantage of computerized signal systems in place that already monitor intersection turning movements, vehicle classification, and speeds. Additionally, current devices for measurement of these data have become low cost. Such data, captured and made accessible to a safety information system, could result in agencies no longer having to conduct expensive manual or other counting programs that yield less data.
Need for a design decision-support system
Given improved data quality and data management through strategies such as effective use of the latest technologies, the current highway design process still would lack a comprehensive means for incorporating safety information. Improved information may only leave the designer with a larger dilemma of how to deal with it. The results of NCHRP Project 17-12 included recommendations for the development of a design decision-support system for safety (DDSS), which has the general objective of assisting the designer in making design decisions at each point in the process.
The recommended framework for a DDSS provides for several elements including user interface, decision-support module, information presentation module, and design analysis module. This is shown diagrammatically in Exhibit 1.
The user interface should be as intuitive as possible for both its end-users and managers. End-users (designers) primarily interact with the system through the decision-support module. This module provides an "intelligent" core to the system. The information-presentation module contains the basic software needed to display information that is derived either directly from the data stores, or generated from the design-analysis module. Finally, the design-analysis module will provide an arsenal of tools for analysis of existing and proposed designs. It would be able to draw upon the best analytical devices available at any given time.
The types of analytical tools discussed to this point are designed to facilitate identification of the underlying factors contributing to highway crashes. The tools are intended to allow the designer to investigate the data to the level of detail desired, through performing a series of inquiries, each of which can "drill down" further into the details available in the data set. In addition to these traditional analytical tools, the module will also deliver to the designer results of analyses using methods potentially based upon safety audit procedures. Safety audits may be used as a vehicle for summarizing and assessing the results from other design-analysis tools available in this set. There also will be a series of analytical devices to test and assess a proposed design. Finally, analytical tools such as those being developed by FHWA for the Interactive Highway Safety Design Model (IHSDM) ( http://www.tfhrc.gov/safety/ihsdm/vdmweb.htm )will be included. The tools will include, but not be limited to, vehicle-driver dynamics simulation, human factors-based design analysis procedures, models for predicting operational and safety outcomes of alternative designs, and economic analysis tools.
The DDSS is structured to assist the designer at the various stages of the process. It will be capable of generating information at various levels of detail from the most aggregate to the most disaggregate. The report demonstrates the "drill down" concept by diagramming and describing processes used in identifying locations considered especially hazardous. Implementation of the proposed system over time should produce substantial benefits to the highway design community and others. Examples are given in Exhibit 2.
Exhibit 1
Generalized Concept for a Design Decision-Support System
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Exhibit 2 - Examples of Impact on Safety Analyses for a Design Project with Implementation of the DDSS Concept |
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Current Practice |
Becomes |
Improved Practice Using the New System |
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Extensive manual assembly of safety data tabulations from different offices within and outside the design agency, requiring many hundreds of staff hours |
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Direct access to a comprehensive data warehouse, within a CADD/GIS environment |
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Manual inspection of hard copy of crash reports from microfilm record, to correct coding errors |
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Pre-screened data minimizes errors including proper location of crash; plus immediate access to digital images of crash reports within CADD/GIS environment |
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Labor-intensive translation of tabulations of key data into calculated fields and graphics using independent spreadsheets and graphics software into which data must be manually keyed |
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Integrated statistical routines, business graphics and advanced data-visualization software; including intelligent collision diagrams plotted on actual geometry and highway attribute time lines |
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Lack of historical traffic data and history of site geometry |
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Data warehouse with records of all available traffic counts, and a continual, up-to-date, history of physical attributes of the site |
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Lack of safety models and limited flexibility of data systems to provide support for positions taken regarding the hazards at the site and the effectiveness of proposed improvements |
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A suite of design analysis models to assess existing and proposed designs from a variety of perspectives, making it feasible to produce a documented and defendable estimate of safety impacts of alternatives. |
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Support for decisions regarding data to use, analysis of it, conclusions to be drawn, and arriving at recommended improvements, comes from staff or specialists. |
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A central decision-support function within the system to provide the user with guidance at every step of the analysis. |
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Decision tools which are applied are done manually |
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A suite of decision tools using the latest developments in decision science, are directly accessible with information generated by the system, based upon the previous work of the designer. |
Organizational and Institutional Considerations
Even when technological tools are available, organizational and institutional issues may limit their usefulness. Key among these issues are lack of integration of data files, dependence on sources of data which may derive from organizations that are not oriented to the data needs of the design community, lack of integration of computer tools, and inadequate designer computer literacy.
Recommended organizational and institutional strategies, include:
1. Policy Actions -giving safety data the status of "strategic enterprise data," establishing safety-performance measures, requiring state and local agencies to participate in safety-data collection oversight, and allowing access to high precision high level, remote imaging for use in obtaining data for documenting the physical highway environment.
2. Organizational Actions - reorganizing agencies to facilitate the efficient and effective collection, management, and use of safety data, establishing entities to provide specialized data and decision-support services, establishing entities dedicated to quality assurance of data, and coalescing state and local agencies into a cooperative safety data collection and management function.
3. Legislative Actions - establishing and authorizing data collection and management functions with oversight over enterprise-strategic data for users within the state, and enabling, through legislation, the implementation of real-time, on-board vehicle dynamics data collection from vehicles involved in crashes.
4. Funding Actions - funding technological advancements, comprehensive research, and training in the use of safety data, establishing mechanisms for cooperative funding of strategic enterprise safety data, and establishing performance-based funding for highway projects.
5. Training Actions - offering training for designers in principles of highway safety related to design; principles, practices and tools of safety analyses; and training to users on new systems for using safety information.
6. Research Activities - continuing support of tools such as FHWA’s Interactive Highway Safety Design Model, development and use of additional tools and methods to support highway design, and committing to develop improved design guides and standards based on improved safety information.
Conclusion
The project findings have led to the basic conclusion that decision makers can have improved safety information to support highway design. To achieve his outcome, the design community should:
1. Recognize the importance of the role of safety in making design decisions, the inadequacy of present methods for incorporating safety, and the need to improve and enhance methods for analyzing safety.
2. Take an active role as part of the broader safety community to help define designers’ requirements for safety data, and work with other users of safety data, in cooperation with collectors and managers of the data, to plan, design, finance and finally implement systems which are useful for design purposes.
3. Begin to work on developing new ways of delivering information, using all the appropriate technology.
4. Better prescribe and promote proper approaches to analysis and decision making.
5. Embark on an ambitious program to demonstrate and develop the decision-support systems that are needed, once improved information is available that justifies their use.
6. Re-examine their institutional, and organizational structure and environment to identify where barriers to positive change exist, and to begin to anticipate how and in what manner organizational change must take place to maintain effective operations.
