The Virginia Department of Transportation (VDOT) currently follows the requirements of the 2003 Manual on Uniform Traffic Control Devices (MUTCD) in terms of the number and type of logo panels that can be placed on logo motherboards. The current standard limits the number of Specific Service signs ("sign structures") along an approach to an interchange or intersection, regardless of the number of service types displayed, to a maximum of four, with the five permissible service categories of Attractions, Camping, Lodging, Food, and Gas. The motherboards are to be displayed in that order in the direction of traffic flow. In addition, there is a standard that each sign assembly ("motherboard") shall be limited to no more than six logo panels and that no service type shall appear on more than one sign. Thus, if one motherboard is set up to display solely the Food category, there would be a limit of six food establishments represented with logo panels. A seventh food logo could not be placed on the existing food motherboard or any other motherboard that has a vacant spot.
With the existing standards, there is usually at least one motherboard that is underutilized; this is most often the camping motherboard. The Attractions category was added beginning with the 2000 MUTCD, and the Attractions logo panels are permitted to share space with the Camping motherboard. Virginia has recently adopted criteria to utilize the Attractions category.
As in most states, there is significant desire by the business community in Virginia to utilize the excess space (on motherboards that do not have six logo panels) by revising the standard that no service type shall be on more than one sign. Most of this desire occurs from businesses in the Food category. There is also a desire in Virginia to better serve motorists with a variety of food opportunities based upon the type of service and the quality of that service. At the time this study was conducted, Virginia was considering adding a Full Service Food category to its accepted service types. With high demand for space and the limit of six Food logos, it might be considered a disservice to the public to not be able to use the vacant space on other service category motherboards.
In order to test the safety and acceptance of logo motherboards containing more than one service type, VDOT began a pilot program in 2000/2002 in which seven interchanges spaced throughout the commonwealth had Full Service Food logo signs added to the camping motherboard (left side of Figure 1). In some cases, these Full Service Food logo signs were installed on their own motherboards when no camping motherboard was present (right side of Figure 1). These signs were installed over a time span of almost two years, from July 22, 2000 through July 10, 2002. The signs have only recently been in place long enough to perform meaningful before-after safety evaluations.
Some of the comparison sites used in the billboard study were logo motherboards. In no case did the comparison sites (including the logo motherboards) show a significant difference from billboards. It would therefore be expected that a similar study with a focus on logo signs rather than billboards would produce similar results. However, the billboard study was time and resource intensive, and produced few significant findings. Therefore, a more basic approach was used for the current study; this approach made efficient use of the available resources while answering the questions raised in the hypotheses section. The approach combined a survey with an accident database analysis to determine the acceptability, understandability, and safety of logo motherboards containing more than one service type.
Permission was obtained from the Federal Highway Administration (FHWA) by VDOT to temporarily remove the standard that no service category (e.g., Food) can be displayed on more than one motherboard. This change has allowed Food logos to be displayed on excess space available on another motherboard (e.g., Full Service Food logo displayed on Camping motherboard when a Food motherboard with six Food logos already exists). There are seven interchanges in the Commonwealth of Virginia where Full Service Food logos have either been added in conjunction with other services (e.g., Camping) or stand alone, resulting in up to eight food logos for the approach to the interchange. These seven interchanges are located along three distinct interstate corridors (I-64, I-81, and I-95). These seven interchanges were used in the study, along with seven adjacent (control) interchanges. The control interchanges did not have more than six Food logo panels, and did not have two service types on any one logo motherboard. These interchange locations are shown below and in Figure 2:
The next two major sections of this report describe the specific methods and results used in the survey and in the accident database analysis. The final section proposes changes to the MUTCD based on the results of these two experiments and the Commonwealth of Virginia's experience in having the Food service type represented on more than one logo motherboard.
United States Department of Transportation - Federal Highway Administration