This section of the Handbook is organized in terms of the same classes of highway features as the Recommendations: I. Intersections (At-Grade), II. Interchanges (Grade Separation), III. Roadway Curvature and Passing Zones, and IV. Construction/Work Zones. Within each of these four classes, subsections are organized in terms of design elements with unique geometric, operational, and/or traffic control characteristics, also consistent with the Recommendations.

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 Recommendations, presented earlier—to entries in standard reference manuals consulted by practitioners in this area. Principal among these reference manuals are the Manual on Uniform Traffic Control Devices (Federal Highway Administration [FHWA], 1988); Manual on Uniform Traffic Control Devices for Streets and Highways [MUTCD], Part VI: Standards and Guides for Traffic Controls for Street and Highway Construction, Maintenance, Utility, and Incident Management Operations (FHWA, 1993); and the Policy on Geometric Design of Highways and Streets [the Green Book] (American Association of State Highway and Transportation Officials [AASHTO], 1994). Other standard references with more restricted applicability, which also appear in the cross-reference tables for selected design elements, include National Cooperative Highway Research Program (NCHRP) Report No. 279, Intersection Channelization Design Guide (Neuman, 1985), and the Roadway Lighting Handbook, Chapter 6 Addendum (FHWA, 1983).

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 documenting older driver performance for the highway features of interest. Observational and controlled field studies were given precedence, together with laboratory simulations employing traffic stimuli and relevant situational cues. Accident data are cited as appropriate. In addition, though of lower priority, some citations reference pertinent findings from "basic" research on age differences in response capability that are tied logically to performance in highway settings.