Improved Methods for Delineating Diverges in Work Zones


Dr. Michael Hunter, Associate Professor, Georgia Tech
Dr. Michael Rodgers, Principal Research Scientist, Georgia Tech
Aaron Greenwood, Graduate Student, Georgia Tech
Chenhao Liu, Graduate Student, Georgia Tech

Project Overview:

The safety of work zones is an area of concern at both the national and state level with more than 600 work zone fatalities recorded in Georgia over the last decade (National Work Zone Safety Information Clearinghouse, 2009). While driver impairment and excessive speed are considered to be two of the predominant causes of these fatalities, driver confusion is known to be either a cause or a confounding factor in many of these fatal accidents (National Work Zone Safety Information Clearinghouse, 2009). This project and subsequent field testing is designed to provide the basis for updating the methods and devices used by The Georgia Department of Transportation for delineation of diverges in work zones with the aim of reducing driver confusion. 

In the broadest sense, delineation systems are collections of control devices (e.g. roadway markers) that provide the driver with information regarding the path, demands, and special characteristics of the road. When applied to work zones, delineation systems have a primary responsibility for information regarding those roadway segments for which traffic is allowed and differentiating these from active work, storage, or refuge areas. As such, the role of delineation systems in defining and identifying particular paths (e.g. exit ramps vs. through lanes) is somewhat compromised. This may be thought of as a “signal to noise” problem in which the presence of a large number of delineation elements makes identification of path specific information more difficult.

In current work zone practice, devices used to delineate diverges are often the same, or very similar to, those used for lane and/or edge of pavement delineation. This can lead to limited contrast between various pathways and the drivers may require secondary cues (e.g. vehicle queues or pavement markings) to locate their desired path. In complex work zones, typical of those associated with limited access highways, drivers may encounter a complex array of signage and delineation that may make identifying these secondary cues more difficult. This can result in driver confusion, hesitation or error associated with finding the correct path through the diverge. The problem is likely even more significant at night or in poor weather where conditions limit the availability of these secondary cues or in the case of inexperienced, impaired, or elderly drivers who may misinterpret the available information.

The central focus of this research is on developing and testing, in a controlled virtual environment, several alternative methods of delineating these diverges to reduce the need for secondary cues without violating driver expectancy. If such methods can be identified, these could reduce driver workload and errors in work zones and improve highway safety for both highway workers and drivers.

The project has two primary objectives: (1) Develop and evaluate several candidate methods/devices for improved delineation of work zone diverges and recommend at least one approach for additional development and subsequent field testing; (2) develop an effective driver simulation method for these candidate methods that can be used to cost-effectively identify those treatments most likely to prove effective in field testing. The primary approach for evaluating the treatments in objective (1) will be the driver simulator developed in objective (2)

Sponsor: Georgia Department of Transportation