Assessing Drivers’ Tailgating Behavior and the Effect of Advisory Signs in Mitigating Tailgating

A human factors study was carried out to assess drivers\u27 tailgating behavior and the effect of advisory signs in mitigating tailgating. Tailgating is a dangerous driving behavior and a leading cause of most rear-end crashes. Through a prior study, serious tailgating was identified on urban Rhode Island highways. It is critical to many urban traffic management authorities to understand tailgating and to explore means to mitigate drivers’ tailgating behavior, especially on urban highways with high-speed and high-volume traffic. Properly designed advisory signs could reduce tailgating and related motor crashes. To assess drivers\u27 behavior with regards to tailgating, a questionnaire survey was developed and given to a number of subjects with daily highway driving experience. The survey is designed to identify causes of tailgating and drivers’ perceptions and engagements on tailgating behavior. Drivers\u27 driving behaviors were further assessed through driving simulation under different traffic conditions. To help mitigate tailgating behavior, advisory signs and an educational video were developed. The effectiveness of these proposed countertailgating measures was assessed in the driving simulation. Subjects’ real driving behaviors were further studied in a follow-up field study. Study results found that the majority had an incorrect sense regarding safe following distance and were tailgating while driving on highways. Heavy traffic was identified as the top tailgating cause. The simulation results confirmed the tailgating phenomenon observed on urban Rhode Island highways. The proposed advisory signs were found effective in mitigating tailgating behavior

Enhancing the Messages Displayed on Dynamic Message Signs

A human factors study was carried out to help enhance ways tocommunicate with highway motorists through dynamic message signs (DMS).Overhead mounted DMSs have been increasingly used by highway authorities inthe United States to present real-time traffic information and travel advice tomotorists. It is critical to post sign messages that can be quickly and clearlyunderstood by motorists, especially in high-volume traffic and construction/repairzones. Properly worded and formatted sign messages could spell the differencebetween comprehension and confusion. Message display factors investigated inthe study include display effects, color schemes, wording, and formats. Twoapproaches were employed in this study. First, a questionnaire survey wasdeveloped to collect motorists’ preferences regarding various message displayfactors. Second, a series of lab driving simulation experiments were set up toassess the effects of these factors and their interactions on motorists’comprehension of DMS messages. Study results suggested that static, one-framedmessages with more specific wording and no abbreviations were preferred.Amber or green or a green-amber combination were the most favored colors.Younger subjects took less response time to the DMS stimuli with higheraccuracy than older subjects. There were no significant gender differences

Using clustered assembly elements in the estimation of potential design for assembly benefits

This paper addresses the variation problem in design for assembly (DFA) benefits in different products. It investigated 12 product cases that employed DFA methodology in their redesign and found that DFA benefits correlate with certain product assembly properties. It explored the correlation relationships using assembly factors consisting of clustered manual handling and insertion assembly elements. Two sets of correlation models for estimating potential DFA benefits were developed. An example is provided to illustrate the estimation procedure and its result

A human factors study on graphic-aided dynamic message signs

This paper describes a human factors study that examines the effects of graphic-aided dynamic message signs (DMSs) on drivers\u27 comprehension of sign messages. Extensive textual messages displayed on overhead-mounted full-size DMSs could be difficult for drivers to comprehend while driving at highway speed. Since graphics are considered more user-friendly than texts, this study explored the use of graphics on DMSs and assessed its effects on human drivers. A questionnaire survey was given and a lab simulation was carried out to measure drivers\u27 responses to the test DMS messages. Results of the lab simulation were reported with a drawn conclusion

A human factors study on message design of variable message sign

Variable message sign (VMS) is a key component of intelligent transportation system (ITS). This paper describes a human factors study focusing on the message design of VMS. It examined within-subject factors, message font size and color; and between-subject factors, subjects\u27 age and gender; and their impacts on human/ITS interface. Experiments were conducted in a motorist performance laboratory where an environment of real video scenes integrated with computer-generated VMS was created to simulate a virtual driving experience. The study found that font color, subjects\u27 age, and gender significantly affected the response time. Green font color resulted in the shortest response time. Older subjects responded faster but with lower accuracy. Female subjects also responded faster with lower accuracy. No meaningful correlations were found between subjects\u27 response time and accuracy. These findings might help promote safe and efficient driving through effective and accurate delivery of information to motorists via VMS

A study on the cause and effect of slow-downs due to dynamic message signs

This paper presents a human factors study on the cause and effect of slow-downs due to messages displayed on dynamic message signs (DMS). DMSs are employed to provide drivers with timely information and traffic advices but the slow-downs caused by them could pose a threat to driving safety. To determine the causes of slow-downs, traffic data collected by a network of mobility technology units (MTUs) were analyzed and results obtained from a questionnaire survey were assessed. Findings obtained from the study recognized major causes of slow downs and identified effective DMS displays that could help ease the slow down effect

Studying the Tailgating Issues and Exploring Potential Treatment

A human factors study consisting of a vehicle headway analysis and a questionnaire survey was conducted in Rhode Island (RI) to investigate tailgating issues and possible means for tailgating treatment. Vehicle headways were collected from highway surveillance videos and serious tailgating issues were identified on RI highways. The results of the questionnaire survey further confirmed the observations made in the vehicle headway analysis that most RI drivers maintained insufficient vehicle headways on highways. Among a few tailgating treatments presented in the survey, most subjects preferred a system consisting of equally spaced, white horizontal bars marked on pavement and overhead graphic-aided dynamic message signs

Studying the Tailgating Issues and Exploring Potential Treatment

A human factors study consisting of a vehicle headway analysis and a questionnaire survey was conducted in Rhode Island (RI) to investigate tailgating issues and possible means for tailgating treatment. Vehicle headways were collected from highway surveillance videos and serious tailgating issues were identified on RI highways. The results of the questionnaire survey further confirmed the observations made in the vehicle headway analysis that most RI drivers maintained insufficient vehicle headways on highways. Among a few tailgating treatments presented in the survey, most subjects preferred a system consisting of equally spaced, white horizontal bars marked on pavement and overhead graphic-aided dynamic message signs