21.6 Daytime Lighting Requirements for Tunnel Entrance Lighting As motorists approach tunnels, they can have trouble detecting low-visual-contrast objects as the result of glare, discrepancies in illumination, and the process of visually adapting to the tunnel...
21.4 Nighttime Driving Headlamp intensity, ambient lighting, and glare all influence how far downstream a motorists can see and their ability to detect and respond to signs. Table 21.2 lists treatments that can reduce nighttime crashes, encourage lower speeds, and...
21.2 Countermeasures for Mitigating Headlamp Glare When a motorist encounters glare from other vehicles, they may experience discomfort or reduced visibility. Several design solutions are available to mitigate the effects of glare, and each carries its own advantages...
20.10 Markings for Roundabouts Roundabout markings must clearly communicate to motorists and other users information about a roundabout’s operation to ensure safe navigation. Yellow lines indicate opposing traffic and white lines signify traffic moving in the same...
20.8 Post-Mounted Delineators Post-mounted delineators are retroreflective marking devices mounted above a road surface to the side of a road. They are installed in series to indicate road alignment and help clarify the alignment in areas where it is confusing or...
20.4 Effectiveness of Symbolic Markings Horizontal signing is sign text painted on the road. It conveys information to drivers without requiring them to look away from the road. For maximum effectiveness, horizontal signs should consist of large, simple elements and...
