Driver performance while texting: even a little is too much.

OBJECTIVE: To examine the impact of text messaging and other in-car behaviors on driving performance under simple and naturalistic road conditions in a driving simulator. METHODS: Data from 28 healthy individuals (12 female) are presented. Participant age ranged from 18 to 28 (mean = 21.0). Average driving experience was 3.8 years (SD = 2.5). Participants completed a baseline loop condition in which they drove normally through a realistic virtual environment. Next, participants drove an identical loop, and at 3 specified points during this drive, participants were required to (1) complete a radio-tuning task; (2) type and send a text message containing "Drexel University"; and (3) type and send "I am driving to the store." Driving performance and task duration was compared between conditions. RESULTS: Across all tasks, both lane management, F(1,27) = 11.1, P = .002, and velocity, F(1,27) = 10.3, P = .003, varied significantly more while task-engaged. Average lane deviation was significantly greater during a text messaging task than during the baseline drive of the same road segment, t(27) = -2.9, P = .007. Comparison of task durations indicated that both texting tasks took significantly longer to complete than the radio task, with the "Drexel University" text (118 s) taking almost twice as long as the radio-tuning task (60 s). Unexpected and novel findings emerged in the evaluation of duration of texting tasks using the varying text-entry methods, with touch-screen modality taking significantly longer than others. CONCLUSIONS: Engaging in secondary tasks while operating a motor vehicle may have deleterious effects on driving performance and increase risk, even under the simplest of driving conditions. Text messaging may constitute a "perfect storm" of risk compared to other in-vehicle tasks such as tuning the car radio. The current investigation demonstrated detrimental effects of text messaging on driving behaviors such as lane maintenance, speed maintenance, and shifts of attention, even under relatively ideal and naturalistic driving conditions (e.g., familiar route, good weather, no traffic).

Driving behaviors among community-dwelling persons with multiple sclerosis.

OBJECTIVE: The current study examined driver behaviors and patterns among drivers with multiple sclerosis (MS) as a function of disease severity and in comparison to drivers without MS. DESIGN: Between-group comparisons of participants with and without MS and cohorts of MS groups at varying levels of severity. SETTING: All data were collected in an outpatient research setting. PARTICIPANTS: Community-dwelling persons (n=66) with clinically definite MS who were active drivers and healthy controls (n=30) were included. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Driving characteristics' measures included (1) driving frequency defined in days and miles driven per week, (2) self-reports of voluntarily limited driving behaviors, (3) changes in driving since MS diagnosis, and (4) self-rating as a driver. Driving performance was also assessed by using pass/borderline performance on a clinical behind-the-wheel evaluation. RESULTS: Mann-Whitney U tests showed a significant difference in driving frequency (P=.021) with MS participants reporting they drove fewer days per week than healthy control group. This was also seen between cohorts of MS drivers (P=.014), with high Expanded Disability Status Scale (EDSS) participants driving less frequently than the low EDSS group. Descriptive observations suggested that participants with moderate EDSS scores drove less and engaged in more self-limiting behaviors. Chi-square tests showed that participants with high EDSS scores were more likely to report changing their driving behavior after diagnosis (P=.01) and were more likely to not pass the behind-the-wheel evaluation (P<.001). CONCLUSIONS: The current findings suggest that as disease severity progresses, differences in frequency of driving (days per week) and the use of self-limiting driving behaviors may vary. Furthermore, the findings also raise questions regarding the overall sensitivity of the most commonly used clinical driving assessment method (the behind-the-wheel evaluation) to accurately capture driving capacity in the milder stages of the disease process. The results indicate the need to consider issues related to driving as MS severity progresses, and, given the progressive nature of MS and the concerns of the validity of the most common clinical driving assessment measures (the behind-the-wheel evaluation), repeated assessment of driving ability may be the most effective approach for identifying driving difficulties among persons with MS.