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Handbook for Designing Roadways for the Aging Population

Part II. Rationale and Supporting Evidence


This section of the Handbook is organized in terms of the same category of highway features as the treatments:

Within each of these five chapters (category), subsections are organized in terms of design elements with unique geometric, operational, and/or traffic control characteristics, also consistent with the treatments. Also, the rationale for the additional "Promising Practices" treatments included under Intersections, Interchanges, Roadway Segments and Construction/Work Zones is presented at the end of their respective chapters.

At the beginning of each subsection within a class of highway features, reference material for a particular design element is introduced using a cross-reference table. This table relates the discussion in that subsection—as well as the associated treatments, presented earlier—to entries in standard reference manuals consulted by practitioners in this area. Principal among these reference manuals are the following:

Other standard references with more restricted applicability, which also appear in the cross-reference tables for selected design elements, include the following:

Material in this part of the Handbook represents, to as great an extent as possible at the time of its development, the results of empirical work with aging driver or pedestrian samples for investigations with the specific highway features of interest. Naturalistic and controlled field studies were given precedence, augmented by laboratory simulations employing traffic stimuli and relevant situational cues. Crash data are cited as appropriate. In addition, some citations reference studies showing effects of design changes, where the predicted impact on (aging) driver performance is tied logically to the results of research on age-related differences in detection, comprehension, response selection, maneuver execution, or other capability needed to safely negotiate the design element.

Page last modified on October 15, 2014.
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