1. Review and evaluate existing research and literature related to the use of graphic-aided DMSs and the effects of such uses on elder drivers.
2. Examine the feasibility of employing graphics in DMS messaging to assist drivers’ comprehension of the message with a particular focus on elder drivers.
3. Compile and/or develop a library of graphic-aided text messages if these were determined to be both feasible and beneficial.
4. Make recommendations to identify, re-design, or create elder-friendly dynamic message signs that are effective for the driving population as a whole.
Highway
Census data for 2000 reported that the percentage of population over 65 years old in the U.S. is 12.4% while it is 14.5% in Rhode Island. This placed Rhode Island as the sixth “oldest” state in the nation. Our two neighboring states, Connecticut and Massachusetts, have each more than 13.5% elders in their population and were ranked 10th and 12th respectively. This aging trend is likely to continue and the elder population in the region could exceed 20 % by the end of this decade. While age may not be a reliable indicator of individual driving performance, it has been reported that elder drivers often take more time in comprehending textual information as well as making slower and less accurate responses based on that information. As a result, elder drivers could pose safety concerns to themselves as well as to other drivers.
Dynamic message sign (DMS) systems have been increasingly used as an important means for arterial highway management in many New England states. They are employed for the purpose of providing drivers with real-time information and advice about roadway and traffic conditions. These signs, often mounted on overhead sign bridges above highways, are capable of displaying extensive messages that might present a challenge to drivers during driving, especially to elderly drivers. Most elders have learned to drive and done much of their driving when no DMSs were in place. The FHWA “Older Driver Highway Design Handbook” (Staplin, L. et al., 2001) cautioned that fixed symbol and word signs could cause difficulty or confusion to elder drivers. Less understood is the reaction of elder drivers when certain information or advice was communicated through DMSs. The question here is how the current DMS signs could be enhanced to adequately meet the needs of elderly drivers.
This proposed project intends to address that question. The study will be initiated by documenting difficulties encountered by the elder drivers and exploring feasible means to enhance DMS displays. It will explore the feasibility of employing graphics to aid message display since common opinions support the superiority of graphically presented information over textually presented information. It will conduct a comprehensive literature search on available transportation publications, manuals and articles, both in the US and internationally, on the application and use of graphic symbols/pictograms for dynamic message signs. To gain insights on this issue, this project will examine elderly drivers in the region via surveys, driving simulation experiments, and later, field studies for identifying and documenting critical DMS message design and display factors. Comparative experiments will be conducted to study their responses to both text-based messaging and graphic-aided messaging. Since the state-of-the-art DMS system is capable of displaying graphic or pictorial information, this project will try to identify how to fully leverage this graphical display advantage to optimize DMS message design in terms of conspicuity, legibility, and comprehension. Overall, it expects to provide specific recommendations to traffic engineers and highway management to help design elderly friendly DMSs that could be noticed, understood, and responded to in time.
The project will take eighteen months to complete. Specific tasks addressing the project’s objectives are described below.
Task 1 - Literature Searches and Documentation
This task will launch a comprehensive review on existing researches, publications, manuals, and articles, both in the US and internationally, related to the application and use of graphic symbols/pictograms for dynamic message signs. It will research any or all FHWA related literature, studies, and policies about the use, development and deployment of signage and graphics as used within the US transportation environment. FHWA's policy and regulations on the use of signage and graphics as contained in the MUTCD or other FHWA publications will be researched and summarized with reference to FHWA’s publication “Older Driver Highway Design Handbook” (Staplin, L. et al., 2001). It will review all previous DMS studies involving elder drivers’ comprehension of DMS messages and it will research and document existing literature regarding the feasibility of using graphics to enhance elder drivers’ comprehension. A review of any "Best Practices" documentation created by state DOT's or agencies will be conducted to provide additional information on the use of graphics and signage in the transportation area.
Task 2 - Summarizing Literature Research
This task will summarize the research of "Best Practices" employed by state DOT's or agencies for the use of graphics, both static and dynamic, in use with dynamic message signs. A library of graphic images that are currently in use with, or in place of, typical text messages used within both the US transportation industry and internationally will be compiled. A special focus will be placed on message content currently utilized on DMS. A list of the meanings of all graphics messages in this library and their relevant text description will be developed. The source of information will include FHWA research, MUTCD, currently available standard graphic packages on most DMS packages, and manufacturers of DMS technologies. It will investigate any other graphical images/pictograms that are currently in use in the international transportation industry that could be adopted for use within the US transportation environment. A summary will be made including a listing of graphic images and pictograms currently in use, or available as a graphics option to DMS and those recommended for further study, evaluation, or use in the transportation industry. These resultant graphics images, including both those commonly accepted in the US and those in use internationally, would be selected for further study and evaluation in the subsequent tasks.
Task 3 - Simulation and Testing of Graphic Images
This task will first assess areas of difficulty that elder drivers might experience in understanding certain text messages and related messaging sequences that are posted to DMS. It will use surveys, interviews, follow-up reports on accidents involving elder drivers, and other appropriate sources, to identify what type, sequencing, or patterns of messages cause the most confusion to elder drivers resulting in slow reaction time. It will next employ questionnaires, driving simulation experiments, and field studies (for details, see “project description”) to establish evaluation criteria for testing the suitability of the use of graphic images for elder drivers as a replacement for any specific confusing text messages. Physical visual and mental acuity parameters will be established for all elderly test subjects, prior to their participation in test message comprehension and evaluation. At this stage, the focus will be determining if specific graphic images enhance the ability of elder drivers to understand and comprehend information being provided via DMS. Of particular interest are messages that can communicate travel time information, as well as those of an emergency nature such as Amber Alerts and Homeland Security Advisories.
Task 4 - Summary, Conclusion and Recommendations for Further Research
This task will prepare and submit a final report including a summary, conclusions and recommendations regarding the feasibility of employing graphic-aided DMS messages to reduce confusion and enhance reaction time for elder drivers. This report will identify those graphic images that work the best and those that do not work well in conjunction with different color settings. The issue of color blindness will be addressed. It will provide an analysis of the findings of related studies or undertakings including any difficulties encountered in subjects’ comprehension of existing text messages.
Overall, the final report will
1. Literature Searches and Documentation
2. Summarization of Literature Research
3. Design Questionnaire and Conduct Survey
4. Set up Simulation Experiment
5. Conduct Simulation and Testing of Graphic Images
6. Conduct Field Study
7. Analyze Test Data and Prepare Final Report
8. Summary, Conclusion and Recommendations for Further Research
$159,090.00
Students will be recruited to carry out different tasks of this project via independent studies, class projects, internships, and thesis researches. Both undergraduate and graduate engineering students will be involved in these activities. Special efforts will be made to attract minority and female students to participate in various phases of this project.
Dynamic message signs are critical to the success of an intelligent transportation system. They provide direct communication between highway traffic management system and human drivers. This project is conducting research to seek means to help enhance elder drivers’ comprehension of DMS messages. It can be linked with many other research projects on ITS. Specially it is built upon previous research work carried out by the PIs. The success of these studies, as evidenced by many publications and presentations resulting from the research, is predictive of the success of this project.
This project will be conducted by a team of experienced researchers led by the Pis who have expertise in dynamic message signs, experimental design, psychology, and human factors studies. With a proven record in this research area, they will ensure that the objectives of this project be fully achieved. Upon completion, a final report will be submitted to URITC and be duplicated and distributed to all interested parties through URITC. Besides printed reports, arrangements will be made with state DOT agencies, via URITC, to publicize the results and findings through presentations, teleconferencing, and workshops. The P.I. Has given many presentations and seminars to RIDOT and URI Transportation Center and has worked closely with the Traffic Management Center personnel in RI in the past. The P.I. Will work with any interested state DOT agency to help them implement the recommended graphic-aided messaging system.
Technical papers based on the final report will be prepared and submitted to TRB, ITE and other professional transportation meetings and conferences. With the permission from URITC, the project findings could also be packaged into CDs and be published through the world-wide-web for greater distribution. The findings of this project will be shared with the transportation engineering community as conference presentations and journal publications. Special efforts will be made to present the project findings to high school and college students to stimulate their interests in transportation engineering research.
This study is unique and important to the New England states due to their growing elderly population and recent deployment of DMS. Many state DOTs are continuously looking to add new technologies and systems to help them better use the current facilities. The proposed graphics-aided DMS messaging provides a natural and friendly interface between highway management system and human drivers and could greatly enhance the function of the intelligent transportation system. Graphical traffic information display on DMS, while being pioneered in several European countries, is new to US highway authorities. With the capability of today’s DMS systems, this project will identify effective means to enhance elder drivers’ responses to DMS messaging display in terms of conspicuity, legibility, and comprehension. While the specific economic benefits of this project are to be determined, significant societal benefits associated with the implementation of elder-friendly DMSs may lead to:
• Reduced accidents, injuries, and fatalities resulted from elderly driving.
• Extended independence, mobility, and safety for elderly drivers.
• Expanded contributions of elderly New Englanders as workers, community members, and volunteers that help ensure a well-integrated society.
We anticipate this project to benefit highway management system, ITS researchers, and elder drivers as a whole, and help attain the mission of URITC. It is believed that this project will lead to many interesting findings in this field and stimulate more research in the area.
Driving safety, dynamic (variable) message sign, graphics (pictogram), graphics-aided message, elder drivers, driving simulation.