Elizabeth A. Harris

Driver distraction and performance effects of highway logo sign design

Driver distraction and safety concerns have been identified for new highway logo sign configurations. This study assessed driver perception of logo signs and distraction under nine-panel, overflow-combination, or standard six-panel formats. A nine-panel sign has nine business panels within a single sign; a six-panel sign has six panels within a sign; an overflow-combination consists of a standard six-panel sign and a six-panel sign displaying two different services (e.g., food and gas). In this study, twenty-four participants searched for target food business logos while driving in a high-fidelity driving simulation under each signage condition. Gas and lodging signs were also displayed along the road in conventional six-panel formats. Dependent variables included signal detection, visual attention allocation, and vehicle control measures. Experiment results showed nine-panel signs drew greater visual attention and produced lower average speed than overflow-combination signs, and produced a lower speeding percentage compared to six-panel signs. However, there was no evidence the new configurations (nine-panel and overflow) caused substantive performance changes with safety implications. This study suggested the use of nine-panel and overflow-combination logo signs may be suitable for interchanges where there are more than six qualifying businesses in a category in terms of driver performance and safety.

A Control Sign Facility Design to Meet the New FHWA Minimum Sign Retroreflectivity Standards

Minimum sign retroreflectivity standards issued by the Federal Highway Administration (FHWA) on January 29, 2008, have focused the attention of administrators and sign managers on improving the nighttime performance of traffic signs. To predict when a sign will need replacement, an agency will need to know when the retroreflectivity of signs with similar characteristics deteriorate to the minimum level established by the FHWA. Currently in the literature, there is limited information about the long-term deterioration behavior of ASTM Type III and IX signs. One way of achieving a better understanding of long-term sign deterioration is to establish an experimental sign retroreflectivity measurement facility (ESRMF). An ESRMF is an arrangement of signs in a controlled area that have their retroreflectivity measured at regular intervals to determine how it deteriorates as a function of time. This article shows how such a facility should look and why. A template is presented that can be used by agencies nationwide for collecting critical sign data to inform policy decisions.

Analysis of Traffic Sign Asset Management Scenarios

Minimum traffic sign retroreflectivity standards proposed for the Manual on Uniform Traffic Control Devices by the FHWA will present numerous management challenges to state and local departments of transportation (DOTs) responsible for traffic sign assets. These DOTs are looking at how to comply with the standard while minimizing sign maintenance costs. This paper presents an analysis of several traffic sign retroreflectivity maintenance methods using a sign asset management simulation based on inspection and sign data gathered in the field. The simulation evaluated 30 sign asset management scenarios in terms of annual maintenance cost per sign and percentage of traffic signs not compliant with the proposed FHWA standard. The simulation results found that, generally, higher costs for sign maintenance resulted in a lower percentage of noncompliant signs. However, for some scenarios using the visual nighttime inspection method, lower percentages of noncompliant signs were found even with relatively low maintenance costs per sign. Increasing the maintenance cost per sign by 10% resulted in an approximately 10% or more reduction in the number of noncompliant signs. It is recommended that DOTs implement a 100% Type III sign replacement policy because Type I signs have a greater life-cycle cost than do Type III signs. DOTs need to allocate an adequate annual budget for sign replacement and should establish their own minimum retroreflectivity standards. The sign asset management simulation developed as part of this study could be modified so that its use could be extended to other DOTs.

Simulation-Based Evaluation of Traffic Sign Retroreflectivity Maintenance Practices

A new highway sign minimum retroreflectivity standard issued by the Federal Highway Administration (FHWA) is compelling agencies to evaluate how to comply while remaining within their budgets. This paper presents the results from a unique microscopic sign system simulation developed to quantitatively evaluate the effectiveness of various sign management practices. The analysis focused on three management methods—nighttime visual inspection, blanket replacement, and expected sign life—and two key sign maintenance functions, sign damage and replacement. The analysis found that sign managers should make prompt replacement of damaged signs a priority. The blanket replacement method was less cost-effective than the nighttime visual inspection method. The expected sign life method was competitive on costs with the visual inspection method while maintaining similar sign conditions. Training inspectors to be more accurate can realize further savings. Skipping inspection or replacement one year, or having an insufficient sign budget, can lead to degraded sign condition levels. The authors offer five best practices that agencies can consider when making sign management decisions.

Development of a Microscopic Simulation to Model Traffic Sign Management and Performance

Minimum retroreflectivity standards issued by the Federal Highway Administration (FHWA) have focused the attention of highway administrators on improving the nighttime performance of signs. This paper outlines the development of a microscopic sign management simulation that facilitates predicting an agency’s level of compliance with the standards and determining the cost of compliance. Using the Arena simulation software, the authors built a model in which each sign was represented as a separate entity and moved through a network of submodels replicating the management and environmental processes experienced annually. The simulation includes submodels for sign damage, inspection, replacement, and deterioration that are modifiable by key input parameters. The simulation model produces several key estimates on an annual basis for the purpose of comparing different sign management scenarios. The resulting model was validated and used to evaluate a scenario representing management conditions in North Carolina...

IT Infrastructure Problems for Asset Management

Transportation infrastructure asset management efforts normally focus on collecting data on items with low volumes and higher capital costs, such as bridges. Road signs and pavement markings, on the other hand, are high volume, low capital cost items but are critical elements of the transportation infrastructure. These high volume assets serve a critical function, safety, and thus they are receiving attention. In particular, the Federal Highway Administration (FHWA) has been working to establish minimum retroreflectivity standards for signs and pavement markings. This paper seeks to address information technology (IT) problems that emerge when developing an overall asset management system for high volume assets and to identify their unique characteristics. These IT problems include asset identification, asset location, data availability, data fragmentation, automated data collection, software selection, and system size and resources. A discussion of the issues related to these problems is presented herein to facilitate the development of more comprehensive systems to manage the automation of infrastructure asset management systems (AMS).