These companion projects, sponsored by the U.S.DOT/ Federal Highway Administration, supported development of the initial Older Driver Highway Design Handbook (FHWA-RD-97-135) and its update that is currently underway. This Handbook provides State and local practitioners with guidance to accommodate older drivers’ diminished functional capabilities through design, operational, and traffic engineering recommendations keyed to specific roadway features. The Handbook was developed to supplement existing standards and guidelines in the areas of highway geometry, operations, and traffic control devices.
The current Handbook, published in 1998, is undergoing revision to incorporate recent research findings and to explain how this resource can be applied as a problem solver at older driver crash sites, or applied preemptively to enhance safety. At the same time, workshops are underway around the country to familiarize State-level engineers and designers with the Handbook. Together, these efforts supported development of three research products:
Staplin, L., Lococo, K., and Byington, S. (1998). Older Driver Highway Design Handbook. USDOT/FHWA Publication No. FHWA-RD-97-135. Washington, D.C.
Staplin, L., Ball, K., Park, D., Decina, L., Lococo, K., Gish, K., and Kotwal, B. (1997). Synthesis of Human Factors Research on Older Drivers and Highway Safety, Volume I: Older Driver Research Synthesis. USDOT/FHWA Publication No. FHWA-RD-97-094. Washington, D.C.
Staplin, L., Gish, K., Decina, L., Lococo, K., Harkey, D., Tarawneh, M., Lyles, R., Mace, D., and Garvey, P. (1997). Synthesis of Human Factors Research on Older Drivers and Highway Safety, Volume II: Human Factors and Highway Safety Research Synthesis. USDOT/FHWA Publication No. FHWA-RD-97-095. Washington, D.C.
This U.S.DOT/Federal Highway Administration project developed guidelines for changes in the geometric design and operations at intersections with the greatest potential to aid in their use by older drivers and pedestrians. Project activities included a literature review to identify age-related diminished capabilities that affect performance at intersections, and examine current design standards and their adequacy for older road users; a set of problem identification studies including crash database analysis, task analysis, focus group discussions, and field observations; an expert panel meeting; plus extensive laboratory and field studies. Opposite left-turn lane geometry (offset amount and direction), right-turn channelization and curb radius, and varying median pedestrian refuge island configurations emerged as key design variables. A comprehensive description of project activities and an excerpt of the guidelines may be found in the Final Report, Executive Summary, and Guidelines Documents, respectively, as follows:
Staplin, L., Harkey, D., Lococo, K., and Tarawneh, M. (1997). Intersection Geometric Design and Operational Guidelines for Older Drivers and Pedestrians, Volume I: Final Report. USDOT/FHWA Publication No. FHWA-RD-96-132. Washington, D.C.
Staplin, L., Harkey, D., Lococo, K., and Tarawneh, M. (1997). Intersection Geometric Design and Operational Guidelines for Older Drivers and Pedestrians, Volume II: Executive Summary. USDOT/FHWA Publication No. FHWA-RD-96-138. Washington, D.C.
Staplin, L., Harkey, D., Lococo, K., and Tarawneh, M. (1997). Intersection Geometric Design and Operational Guidelines for Older Drivers and Pedestrians, Volume III: Guidelines. USDOT/FHWA Publication No. FHWA-RD-96-137. Washington, D.C.
This project, sponsored by the U.S.DOT/Federal Highway Administration, measured age-related differences in the ability of drivers to discriminate downstream horizontal curvature at night under low beam headlight illumination with varying delineation treatments. Scientex’s role as a subcontractor in this project was to conduct a film-based simulation study to prioritize treatments for field evaluation. The study methodology, findings, and recommendations are presented in the following Final Report:
Pietrucha, M., Hostetter, R., Staplin, L., and Obermeyer, M. (1994). Pavement Markings and Delineation for Older Drivers. U.S.DOT/FHWA Publication No. FHWA-RD-94-145. Washington, D.C.
The objective of this U.S.DOT/ Federal Highway Administration project was to identify specific maneuver difficulties experienced by older drivers, taking into consideration left turns at intersections, right turns into traffic, highway crossing maneuvers, freeway entry/merging, freeway exit/weaving, car following, car overtaking, and passing a lead vehicle on a 2-lane highway. A literature review and crash analysis were performed, plus laboratory and field trials to measure time-to-collision estimates and minimum safe gap judgments for older and younger drivers. The results indicated that older drivers are much less sensitive to the speed of approaching vehicles at intersections than are younger drivers, leading to turning decision errors. In addition, measurement bias as a function of varying simulator display attributes was identified with implications for future simulation studies of driver response capabilities. The methodology and results are described in the following Final Report and journal articles:
Staplin, L., Lococo, K., and Sim, J. (1992). Traffic Maneuver Problems of Older Drivers. USDOT/FHWA Publication No. FHWA-RD-92-092. Washington, D.C.
Staplin, L. and Lyles, R.W. (1992). "Age Differences in Motion Perception and Specific Traffic Maneuver Problems." Transportation Research Record, 1325.
Staplin, L. (1995). "Simulator and Field Measures of Driver Age Differences in Left Turn Gap Judgments." Transportation Research Record,1485, pp. 49-55.
In this project, sponsored by the Pennsylvania Department of Transportation, a vision screening program was implemented in conjunction with the driver renewal process to define the magnitude of the vision impaired driver problem in Pennsylvania, the costs of detection, the probability of correction, and the impact upon crash reduction. Results of screenings conducted on 12,710 licensed operators showed that 3.3 percent of the sample "failed" the minimum state standard of 20/40 binocular visual acuity and 140 degrees horizontal visual field. Most of the vision failures were related to refraction problems, cataracts, and glaucoma. Failure on a combined criteria that incorporates the current PennDOT standard (binocular acuity of 20/40 and horizontal visual field of 140 degrees) and a contrast sensitivity criterion produced the strongest relationship linking poor vision and high crash involvement, especially for 66-75 and 76+ driver age groups. Neither visual acuity nor horizontal field measures in isolation were significantly related to crash involvement. Periodic screening using the combined criterion, for drivers over age 55 was recommended. The project activities and recommendations are detailed in the following Final Report, and journal articles, respectively:
Decina, L. E., Staplin, L., and Spiegel, A., (1990). Correcting Unaware Vision Impaired Drivers. Final Report No. 730009. Pennsylvania Department of Transportation: Harrisburg, Pennsylvania
Decina, L. E. and Staplin, L. (1993). "Retrospective Evaluation of Alternative Vision Screening Criteria for Older and Younger Drivers." Accident Analysis and Prevention; 25(3); 267-275.
Decina, L. E., Staplin, L., Spiegel, A., and Knoebel, K. Y. (1991). "Contrast Sensitivity and Driver Vision Screening: An Accident Analysis." Proceedings of the 35th Annual Conference - Association for the Advancement of Automotive Medicine; 133-148.
In these companion projects, sponsored by the Pennsylvania Department of Transportation a new diagnostic index for assignment of crash risk was developed and validated. First, a linear discriminant function was developed as a multivariate model for predicting driving negligence, based upon three-year crash histories of 7,494 randomly-selected PA drivers. Drawing upon 71 driver performance, driver characteristic, vehicle, and demographic factors as potential predictor variables, this model, termed the Driver Improvement Index, correctly classified 79.1 percent of the random sample into "crash" versus "no crash" categories. The second study determined the validity of Driver Improvement Index when applied to a significantly larger random sample of 50,000 drivers evenly split between those who had no crashes versus those who had multiple crashes over a three-year interval. The Driver Improvement Index correctly classified 80.1 percent of the drivers as either no-crash or multiple-crash drivers.
Driver improvement program treatments were developed, implemented, and evaluated in this research, as well, targeted to three levels of demonstrated negligence (points). These interventions included an advisory/warning letter, a Special Written Point Examination (English and Spanish versions), and a classroom exercise for small groups labeled "Decisions for Safe Driving." The letter achieved moderate effectiveness in violation reduction, the written examination achieved significant reductions in both crashes and violations, and the class failed to demonstrate a benefit on either measure. Project deliverables included a Final Report documenting the activities of the research, a journal article, and a Special Point Exam and Handbook, as follows:
Staplin, L., Lococo, K., and Knoebel, K. (1992). Driver Improvement Index Pilot Study, Final Report No. PA-91-021-85-05. Pennsylvania Department of Transportation: Harrisburg, Pennsylvania.
Staplin, L. (1993). "A Cost-Effective Driver Improvement Treatment in Pennsylvania." Transportation Research Record, 1401, pp. 26-36.
Pennsylvania Department of Transportation Special Point Examination Driver’s Handbook.
Pennsylvania Department of Transportation Special Point Examination Test Booklet.
Scientex provided technical oversight and developed product content for the prime contractor in a PI&E campaign addressing DUI, novice drivers, older drivers, seasoned drivers, truck safety, aggressive drivers, and occupant protection. Research methods included database searches, focus groups, and telephone interviews. Scientex teamed with Kelly Michener to develop an "Older Driver Self-Evaluation Guide," and a "Parent-Teen Tutor’s Guide," for the graduated licensing program. These two products are listed below:
How to Steer Them to Safe Driving. A Comprehensive Guide to Help Teach New Drivers to Be Safe Drivers. Pennsylvania Department of Transportation: Harrisburg, PA.
Driving Safely As You Get Older: A Personal Guide. Pennsylvania Department of Transportation: Harrisburg, PA.
Strengths and weaknesses of the Pennsylvania Driver License Examination Program were identified, with recommendations to increase both traffic safety and program efficiency. A subsequent pilot study was conducted to test enhancements developed following review of programs in other jurisdictions, with specific emphasis on written (road sign and law) and Class 1/passenger vehicle performance (on-road) examinations. Recommendations for future implementation were then made based upon analysis of the pilot study data. The project activities and recommendations are contained in the following Final Report:
Byrnes, A. and Staplin, L. (1986). Analysis of the Pennsylvania Driver's License Examination Program. Project Final Report No. 84-18. Pennsylvania Department of Transportation: Harrisburg, Pennsylvania.