Skip to main content

Currently Skimming:


Pages 289-299

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 289...
... Chapter 8/Illumination Page 8-1 Roundabouts: An Informational Guide CHAPTER 8 ILLUMINATION CONTENTS 8.1 INTRODUCTION .
From page 290...
... Roundabouts: An Informational Guide Page 8-2 Chapter 8/Illumination LIST OF EXHIBITS Exhibit 8-1 Recommended Illuminance Levels for Roundabouts .
From page 291...
... Chapter 8/Illumination Page 8-3 Roundabouts: An Informational Guide 8.1 INTRODUCTION For a roundabout to operate satisfactorily, a driver must be able to enter the roundabout, move through the circulating traffic, and separate from the circulating stream in a safe and efficient manner. Pedestrians must also be able to safely use the crosswalks.
From page 292...
... Roundabouts: An Informational Guide Page 8-4 Chapter 8/Illumination To improve the users' understanding of the roundabout's operations, the illumination should be designed to create a break in the linear path of the approaching roadway and emphasize the circular aspect of the roundabout (1)
From page 293...
... Chapter 8/Illumination Page 8-5 Roundabouts: An Informational Guide exiting roadway, which takes approximately one to two seconds. In addition, it is preferable to avoid short-distance dark areas between two consecutive illuminated areas (9)
From page 294...
... Roundabouts: An Informational Guide Page 8-6 Chapter 8/Illumination 8.4 EQUIPMENT TYPE AND LOCATION To determine the appropriate lighting equipment and pole location, a photometric analysis is required. The number of fixed objects in the public right-of-way adjacent to a roundabout should be considered when identifying optimal locations for lighting poles; fewer poles with higher intensity light fixtures minimize the number of fixed objects.
From page 295...
... Chapter 8/Illumination Page 8-7 Roundabouts: An Informational Guide section. The IES Design Guide for Roundabout Lighting recommends lighting be placed around the perimeter of the roundabout and at locations on the approach side of the crosswalks.
From page 296...
... Roundabouts: An Informational Guide Page 8-8 Chapter 8/Illumination Illumination Type Advantages Disadvantages Perimeter illumination Illumination can be strongest around critical bicycle and pedestrian areas. Continuity of poles and luminaires is maintained for the illumination of the lanes, as well as good visual guidance on the circulatory roadway.
From page 297...
... Chapter 8/Illumination Page 8-9 Roundabouts: An Informational Guide speeds of errant vehicles. In particular, care should be given to placement of poles along the exit leg of the roundabout to consider potential paths of errant vehicles that may not successfully navigate the exit curvature upon leaving the circulatory roadway.
From page 298...
... Roundabouts: An Informational Guide Page 8-10 Chapter 8/Illumination Inscribed Circle Diameter: 140 ft (43 m) Equipment: Cobras over circulatory roadway: 200 W HPS, Type M-C-III, 30 ft (9.1 m)
From page 299...
... Chapter 8/Illumination Page 8-11 Roundabouts: An Informational Guide 8.5 REFERENCES 1. Design Guide for Roundabout Lighting.

Key Terms



This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.