Studies have shown that teenage drivers are less attentive, more frequently exhibit risky driving behavior, and have a higher fatal crash risk in the presence of peers. The effects of direct peer pressure and conversation on young drivers have been examined. Little is known about the impact on driving performance of the presence of a non-interacting passenger and subtle modes of peer influence, such as perceived social norms. The goal of this study was to examine if teenagers would engage in more risky driving practices and be less attentive in the presence of a passenger (vs. driving alone) as well as with a risk-accepting (vs. risk-averse) passenger. A confederate portrayed the passenger's characteristics mainly by his non-verbal attitude. The relationship between driver characteristics and driving behavior in the presence of a passenger was also examined. Thirty-six male participants aged 16-17 years old were randomly assigned to drive with a risk-accepting or risk-averse passenger. Main outcomes included speed, headway, gap acceptance, eye glances at hazards, and horizontal eye movement. Driver characteristics such as tolerance of deviance, susceptibility to peer pressure, and self-esteem were measured. Compared to solo driving, the presence of a passenger was associated with significantly fewer eye glances at hazards and a trend for fewer horizontal eye movements. Contrary to the hypothesis, however, passenger presence was associated with a greater number of vehicles before initiating a left turn. Results also showed, contrary to the hypothesis, that participants with the risk-accepting passenger maintained significantly longer headway with the lead vehicle and engaged in more eye glances at hazards than participants with the risk-averse passenger. Finally, when driving with the passenger, earlier initiation of a left turn in a steady stream of oncoming vehicles was significantly associated with higher tolerance of deviance and susceptibility to peer pressure, while fewer eye glances at hazards was linked to lower self-esteem. While the results of this study were mixed, they suggest that the presence of a teenage passenger can affect some aspects of teenage driver behavior even in the absence of overt pressure and distraction. Results are discussed in relation to theoretical concepts of social influence and social facilitation models.

Young drivers (younger than 25 years of age) are overrepresented in crashes. Research suggests that a relevant cause is inadequate visual search for possible hazards that are hidden from view. The objective of this study was to develop and evaluate a low-cost, fixed-base simulator training program that would address this failure. It was hypothesized that elicited crashes in the simulator training would result in better scanning for latent hazards in scenarios that were similar to the training scenarios but situated in a different environment (near transfer), and, to a lesser degree, would result in better scanning in scenarios that had altogether different latent hazards than those contained in the training scenarios (far transfer). To test the hypotheses, 18 trained and 18 untrained young novice drivers were evaluated on an advanced driving simulator (different from the training simulator). The eye movements of both groups were measured. In near transfer scenarios, trained drivers fixated the hazardous region 84% of the time, compared with only 57% of untrained drivers. In far transfer scenarios, trained drivers fixated the hazardous region 71 % of the time, compared with only 53% of untrained drivers. The differences between trained and untrained drivers in both the near transfer scenarios and the far transfer scenarios were significant, with a large effect size in the near transfer scenarios and a medium effect size in the far transfer scenarios [respectively: U = 63.00, p(2-tailed) < .01, r = −.53, and U = 88.00, p(2-tailed)<.05,r = −.39].

It is hard to overestimate the importance of highway signage that can convey large amounts of information in a very short period of time, especially when the traffic is heavy and moving quickly. Drivers who are slow to read a sign or drivers who make a decision at the last moment can be the cause of minor incidents, which slow traffic to a crawl for hours or, worse yet, be the cause of major crashes. Airports are one example of an environment where it is necessary to convey large amounts of information in a very short period of time. Arriving passengers must find their terminal. TypiCally, the names of the airlines departing or arriving at a given terminal are all listed together on a sign. Lists of up to 20 names are not uncommon. We tested altemative ways of formatting the airline terminal signs designed to reduce the scanning time. The results apply generally to the design of any signs intended to convey large amounts of information in a very short period of time.

In recent years there has been a considerable increase in the systems used to provide real-time traffic information to motorists. Examples of such systems include dynamic message signs and 511 travel information systems. However, such systems can be used to reduce congestion—one of their primary purposes—only if one can predict the route choices of drivers as a function of the information displayed. This simulator study looks at the diversion pattern that occurs when delays are reported ahead on the main route and how these diversion patterns vary as a function of delay times (for numerical delay signs), message content (for categorical delay signs), use of 511, and drivers’ familiarity with the alternative route travel times across two different age groups. For numerical delay signs, the study shows that one can reliably predict the diversion frequencies at the different delays and across the different ages; then it is possible for traffic engineers to know ahead of time how likely it is for drivers to take an alternative route. For categorical delay signs, the findings indicate that drivers’ knowledge of the alternative route travel time affects the choices of older versus younger or middle-aged adults differently. When the times are not known, the two groups behave differently; when the times are known, the groups behave similarly. This finding suggests that traffic engineers should try where possible to present the alternative route travel times as well as the delays on the main route.

Two-lane freeway exits in which the left-hand exit lane also continues as a through (option) lane are becoming increasingly common. Potential problems can arise at these exits when drivers become confused by the signing and can lead to increases in driver frustration, incidents, and congestion. These problems have not been studied in any detail, especially in circumstances in which the signs recommended in the Manual on Uniform Traffic Control Devices for Streets and Highways cannot be used. Such is the case in the underground sections of I-93 through downtown Boston, Massachusetts, where the signs can be no more than 3 ft high. To arrive at a better understanding of these problems, the Massachusetts Highway Department evaluated a number of different ways of informing drivers that the left-hand lane of a two-lane exit functioned as both an exit lane and a through lane. The entire underground sections of northbound and southbound I-93 were simulated on a computer. Participants in an experiment sat in an actual car surrounded by three screens onto which was projected the virtual world and manipulated the controls of the car just as they would those of an ordinary vehicle. The participants were given a particular destination on each drive. The exact path was recorded, and misses and unnecessary lane changes could be derived from the recording. Six different signs were evaluated in three experiments. A function that could be used to rank the effectiveness of a given sign on the basis of the participants’ different responses to the sign was developed. Clear recommendations for the signing of two-lane freeway exits with an option through lane in extreme conditions emerged from the experiments.