Skip to main content

Work Zone Speed Management (2015) / Chapter Skim
Currently Skimming:


Pages 20-26

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 20...
... 20 chapter two WORK ZONE SPEED LIMITS INTRODUCTION This chapter discusses criteria and policies for setting work zone speed limits, penalties for exceeding the limits, and several devices and technologies that are intended to reduce work zone speeding by enhancing driver awareness of speed limits. SETTING WORK ZONE SPEED LIMITS Several factors deserve consideration when selecting an appropriate work zone speed limit.
From page 21...
... 21 limits of 70 mph found a reduction in speed variance when the work zones were posted at 50 or 60 mph instead of 70 mph (Hou et al.
From page 22...
... 22 limit; the criteria include narrow lane width, narrow shoulder width, lateral shifting of the lanes, work operations close to an open lane, and traffic operating on shoulders, temporary pavement, or gravel. A simplified flowchart for setting work zone speed limits published by the Roadway Safety Consortium in 2010 is reproduced as Figure 8.
From page 23...
... 23 • Traffic mix and vulnerable road users • Crash history • Road shoulder width and pavement quality • Road delineation • Road and lane widths • Abutting land development • Type of intersections and traffic control • Traffic volume and traffic flow • Types of vehicles allowed • Access • Free-flow speed • Ability to overtake [pass] safely (within sight distance)
From page 24...
... 24 Method Examples Where Speed Limit Reductions May Be Used Advisory speed limits Used whenever an unexpected change in geometrics is caused by the work activity ▪ Bumps ▪ Low shoulders ▪ Drop-offs ▪ Limited but not substandard sight lines or stopping sight distance ▪ Limited but not substandard horizontal or vertical alignment ▪ Gravel surfaces (length less than 500 m) ▪ Temporary lane closures ▪ Milled surfaces Regulatory Speed Limits Used for temporary worker safety Only to be used when workers present.
From page 25...
... 25 The use of advance warning signs such as those shown in Figure 9 is generally considered a most effective practice to provide drivers with additional notice, particularly if the reduction is 10 mph or more. "The addition of advisory speed panels to work zone warning signs may also help in conveying to drivers appropriate speeds through specific portions of the project" (Bryden and Mace 2002)
From page 26...
... 26 data the report suggested that double-fine zones may help in reducing crash rates. A study published in 2000 examined the short-term effect of a double-fine law that was implemented in Texas on January 1, 1998 (Ullman et al.

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.