Bryan J Katz

Business Logo Signing

Specific service signs provide motorists with business identification information along freeway approaches to interchanges. The Manual on Uniform Traffic Control Devices limits the number of these signs along an interchange approach to four and the number of logo panels per sign to six, although there are continuing requests to increase the number of panels allowed per sign. The present research evaluated specific service signs with four, six, or nine panels per sign and with all logo-based panels or all text-based panels. Participants were asked to determine whether a particular business was present on a sign. Mean reaction times indicated that for nine-panel signs, younger drivers took approximately 2.2 s to determine correctly the presence of a business, while older drivers took approximately 2.9 s. In considering drivers of all ages, an increase from six to nine panels brings mean reaction times from 1.8 s to 2.5 s for text signs and from 1.9 s to 2.5 s for logo signs. In a second task, participants were given 2 s to view each sign before reporting the businesses present on the sign. Participants reported three to four businesses on average, regardless of the number of panels on the sign. Considering the generally accepted standard that eye glances away from the forward roadway for greater than 2 s are unsafe, the study concluded that the benefit of providing more service information is presumably not great enough to outweigh the risk of information overload and driver distraction.

Field Evaluation of Truck Weigh Station Operations

Weigh-in-Motion (WIM) systems can improve the capacity of weigh-station operations by screening trucks traveling at high speeds and requiring only trucks within a threshold of a maximum permissible weight or axle load to be weighed on more accurate static scales. The efficiency of a weigh station is highly dependent on the accuracy of the WIM screening system. This article examines the operations at the Stephens City weigh station in Virginia. The case study evaluates the accuracy of the WIM technology, in addition to the operations of the weigh station, in terms of service time (time that the truck is on static scale), queued delay, and system time. Specifically, the study demonstrated that the WIM systems did not conform to American Society for Testing and Materials (ASTM) standards for Type III WIM systems. The study also demonstrated that by incorporating a weight threshold of 96% only 16% of the trucks that were identified as possible violators actually violated the legal limits. Consequently, 84% of the trucks that were required to enter the static scale were forced to incur unnecessary delays and caused additional delays for violating and nonviolating trucks.

Evaluation of Truncated Arrow per Lane Guide Signs

Some freeway and expressway interchanges contain an interior option lane in which traffic in that lane can choose to exit or remain on the route at the split. The 2009 Manual on Uniform Traffic Control Devices requires that either the Overhead Arrow per Lane or the diagrammatic guide sign designs be used for all multilane exits at major interchanges that have an optional exit lane that also carries the through route. However, some practitioners believe that it is cost-prohibitive and unnecessary to install Overhead Arrow per Lane guide signs at minor interchanges. Given the benefits of Overhead Arrow per Lane guide signs, a condensed version of an Overhead Arrow per Lane guide sign is needed for use where a full Overhead Arrow per Lane guide sign is not a reasonable option. A truncated version of the sign, which could be displayed on existing cantilever structures, would eliminate the expense of installing larger structures while still reaping the benefits of the Arrow per Lane sign concept. This study identified five signing alternatives for potential use at minor and intermediate interchanges with multilane exits and an option lane. Participants viewed videos of either Overhead Arrow per Lane guide signs or one of the four truncated alternatives. Participants were asked to indicate which lanes they could use to exit in some scenarios and which to use to proceed through in other scenarios. Participants typically understood the alternatives that provided information about both through and exiting traffic (80% comprehension), whereas alternatives that provided information about exiting traffic, with little to no information about through traffic, resulted in relatively low comprehension (38%).

Feasibility of Using In-Vehicle Video Data to Explore How to Modify Driver Behavior That Causes Nonrecurring Congestion

This research report—a product of the Reliability focus area of the second Strategic Highway Research Program (SHRP 2)—presents findings on the feasibility of using existing in-vehicle data sets, collected in naturalistic driving settings, to make inferences about the relationship between observed driver behavior and nonrecurring congestion. General guidance is provided on the protocols and procedures for conducting video data reduction analysis. In addition, the report includes technical guidance on the features, technologies, and complementary data sets that researchers should consider when designing future instrumented in-vehicle data collection studies. Finally, a new modeling approach is advanced for travel time reliability performance measurement across a variety of traffic congestion conditions.

Determining Colors for Traffic Control Devices at Transponder-Controlled Tollbooth Lanes with a Sign Simulator

The number of toll roads is increasing in the United States, and drivers face signing practices that vary greatly across jurisdictions. In addition to the increase in toll roads, there is an increase in the use of electronic toll collection (ETC) transponders. The present study was undertaken to develop standard signing practices—specifically for background color, legend color, underlay color (i.e., the background color for the pictographs), and pictograph—for ETC-supported toll road signs. The study reviewed selected ETC toll road signs in the United States to help select candidate elements and options to be used in a laboratory experiment. On the basis of that review, 120 signs depicted on 35-mm slides were developed with a standard sign-design software package. The signs were presented to 60 participants (equally divided by sex and age group) in the recently updated Turner-Fairbank Highway Research Centers sign simulator. The signs were shown to participants starting at a simulated distance of approxi...

Field Study of Driver Exiting Behavior at Complex Interchanges

A field study explored driver behavior at complex interchanges throughout the United States in order to better understand geometric, signing, and marking characteristics that influence driving behavior and lane selection. Two types of data were collected at 13 interchanges spanning four states: videos from fixed-location cameras, and videos from unmanned aerial vehicles. Findings from the study highlight common behavior as drivers negotiate complex interchanges. For each interchange studied, video was reduced to track vehicle paths throughout the study site. Although data were captured on both through and exiting traffic, the focus of this review was on the exiting vehicles. No major safety issues were observed through the study. One common finding across all sites was that exiting traffic was found to most commonly use the EXIT ONLY lane rather than the option lane. In addition, few common behaviors identified through the video show last-minute lane changes; drivers typically entered their target lane well upstream of the interchange.

Evaluation of Overhead-Mounted Sign Alternatives for Lane Use and Destination Information on Multilane Conventional Roads

The essential elements of signs with lane use and destination information combined were evaluated to determine the element or combination of elements best comprehended by road users. The sign elements in this study were evaluated only for overhead-mounted guide signs on approaches to multilane conventional intersections. The research team identified existing standards in the Manual on Uniform Traffic Control Devices (MUTCD) for similar signs or related sign elements that might already have been applied by states to communicate lane use and destination information combined. The team also identified any elements that might have been relevant but were not yet included in MUTCD. This information was used to select the following variables for use in combination on signs with lane use and destination information: lane designation, construction type, destination direction, arrow type, and vertical separator lines. Combinations of these variables were then used to develop 18 experimental signs. Most alternatives were well understood by the research participants. Signs with single-lane designations were understood significantly better than signs with shared-lane designations. The study shows that when overhead-mounted guide signs with lane use and destination information combined are designed for approaches to multilane conventional road intersections, the amount of information and sign complexity must be kept low, especially for signs with information on shared lanes, in which information for multiple shared lanes can be confusing to drivers. The study shows no difference in comprehension on the basis of the use of vertical separator lines, arrow type, or construction type; however, in some situations these designs can quickly become complex.

Evaluation of Comprehension and Legibility of International and Domestic Nonstandard Symbol Signs

This paper documents a research project that evaluated proposed new traffic signs to ensure that the signs were effective when human factors requirements were taken into consideration. The following sign messages were selected for symbol development and evaluation: combination horizontal alignment–advisory speed, congestion ahead, cross-street preferential lane warning, do not enter, do not pass, electric-vehicle charging station, fallen rocks, flagger ahead, low-shoulder warning, maximum width, no left turn ahead, railroad crossing on leg of roundabout, road narrows, survey crew, trolley crossing, uneven lanes, and winery. The team conducted 96 surveys to determine driver comprehension and legibility for each alternative sign design. The surveys were administered to the general driving public at the Turner–Fairbank Highway Research Center in McLean, Virginia. On the basis of driver input and the results of the comprehension and legibility testing, the research team provided recommendations on symbols that should be included in the next edition of the Manual on Uniform Traffic Control Devices.

Electric Vehicle Charging Station Signs: An Evaluation of Driver Comprehension and Perceived Risk

As drivers continue to purchase electric vehicles, there is an increasing demand for electric vehicle charging stations and, consequently, signing for these stations. Previous research evaluated a sign which was recommended to the Manual on Uniform Traffic Control Devices (MUTCD) team for addition to the MUTCD; however there remained concerns that drivers’ perceptions of electric vehicle charging stations signs had not been adequately addressed. The present research focused on driver comprehension and perceived risk of electric shock in regard to two electric vehicle charging station signs. Members of the driving public completed a computer-based survey which consisted of open-ended questions, rating tasks, and ranking tasks. Drivers did not necessarily associate a risk of electric shock with electric vehicle charging stations. In fact, nearly 100 percent reported that they would feel comfortable using a public electric vehicle charging station. When asked specifically about the risk of electric shock, statistically significant differences in sign alternatives arose only in the risk of electric shock implied by the sign. Further, drivers perceived the risk of shock from using an electric vehicle charging station as lower than many commonly used items which contain an electric charge (e.g., toaster, hair dryer, and extension cord). Given that both alternatives were well comprehended, either sign is suitable for use.

Analysis of Enforcement Techniques for DWI Checkpoints and Their Impact on Traffic Operations

This paper documents a research project investigating the effects of various driving-while-intoxicated (DWI) checkpoint setup scenarios on overall traffic operations. According to NHTSA, 13,470 people were killed in alcohol-related crashes in 2006. Of the 13,470 fatalities, 64% involved drivers with a blood alcohol content of 0.08 or higher. For this reason, state and local police departments tend to conduct DWI checkpoints during the night, when police officers detain vehicles traveling on a roadway and interview drivers to determine suspicion of alcohol use. For planning and budgeting purposes, police departments need to be able to effectively plan a setup for DWI checkpoints. The goal of the project is to provide police departments with data and methodologies to analyze the impact of their checkpoints on traffic operations. Seven scenarios were investigated on the basis of interviews with several police departments: one officer stopping every vehicle, one officer stopping every second vehicle, one officer stopping every fifth vehicle, one officer stopping every tenth vehicle, two officers stopping every vehicle, four officers stopping every vehicle, and four officers stopping every second vehicle. Each scenario was varied to include 50, 100, 150, 200, 300, 400, 500, 600, 700, and 800 vehicles per hour (or vehicles per hour per lane) to obtain a wide range of limiting values after which DWI checkpoints would cause extraordinary amounts of delay. The paper includes the results for each scenario that can be used by police departments to recognize the potential impacts on vehicle delay.