Susan A. Soccolich

Comparing Handheld and Hands-free Cell Phone Usage Behaviors While Driving

Objective: The goal of this study was to compare cell phone usage behaviors while driving across 3 types of cell phones: handheld (HH) cell phones, portable hands-free (PHF) cell phones, and integrated hands-free (IHF) cell phones. Naturalistic driving data were used to observe HH, PHF, and IHF usage behaviors in participants’ own vehicles without any instructions or manipulations by researchers. Methods: In addition to naturalistic driving data, drivers provided their personal cell phone call records. Calls during driving were sampled and observed in naturalistically collected video. Calls were reviewed to identify cell phone type used for, and duration of, cell phone subtasks, non–cell phone secondary tasks, and other use behaviors. Drivers in the study self-identified as HH, PHF, or IHF users if they reported using that cell phone type at least 50% of the time. However, each sampled call was classified as HH, PHF, or IHF if the talking/listening subtask was conducted using that cell phone type, without considering the drivers self-reported group. Results: Drivers with PHF or IHF systems also used HH cell phones (IHF group used HH cell phone in 53.2% of the interactions, PHF group used HH cell phone for 55.5% of interactions). Talking/listening on a PHF phone or an IHF phone was significantly longer than talking/listening on an HH phone (P <.05). HH dialing was significantly longer in duration than PHF or IHF begin/answer tasks. End phone call task for HH phones was significantly longer in duration than the end phone call task for PHF and IHF phones. Of all the non–cell phone–related secondary tasks, eating or drinking was found to occur significantly more often during IHF subtasks (0.58%) than in HH subtasks (0.15%). Drivers observed to reach for their cell phone mostly kept their cell phone in the cup holder (36.3%) or in their seat or lap (29.0% of interactions); however, some observed locations may have required drivers to move out of position. Conclusions: Hands-free cell phone technologies reduce the duration of cell phone visual–manual tasks compared to handheld cell phones. However, drivers with hands-free cell phone technologies available to them still choose to use handheld cell phones to converse or complete cell phone visual–manual tasks for a noteworthy portion of interactions.

Drug Use and Involvement in a Safety-Critical Event: Pilot Study Using Naturalistic Truck Data

This study used the Naturalistic Truck Driving Study data set to test the feasibility of applying naturalistic data to evaluation of the relationship between prescription (Rx) and over-the-counter (OTC) drug use and involvement in a safety-critical event (SCE). The risk of drug use was calculated by comparing SCEs and baseline epochs that occurred within a drugs half-life with SCEs and baseline epochs that did not occur within a drugs half-life (for the same half-life period). This research found that nearly 97% of commercial motor vehicle drivers used an OTC drug at least once (mostly caffeine), and 25% used at least one Rx drug. Furthermore, Rx and noncaffeine OTC drug use was not associated with an increased or decreased risk of involvement in an SCE. As caffeine was the only drug classification used multiple times by many drivers, this odds ratio analysis was the only analysis performed. Caffeine use while driving was found to be associated with a decreased risk of SCE involvement in all seven half-lives (half-life odds ratios ranging from 0.44 to 0.66). This project illustrated the feasibility of using a naturalistic driving approach to assess the risk associated with Rx and OTC drug use while driving. It is possible that analyses for specific medications could be performed with a sufficiently large sample of drivers who used each classification of drug.

The relationship between the Driver Behavior Questionnaire, Sensation Seeking Scale, and recorded crashes: A brief comment on Martinussen et al. (2017) and new data from SHRP2

We provide a brief comment on the work of Martinussen et al. (2017), who studied the relationships between self-reported driving behavior, registered traffic offences, and registered crash involvement. It is argued that if the number of crashes is small, then the correlation with crashes is also small. Our analysis of the SHRP2 naturalistic driving study shows that the violations score of the Driver Behavior Questionnaire and the Sensation Seeking Scale exhibit small correlations with recorded crashes, and small-to-moderate correlations with recorded near-crashes and measures of driving style.

The impact of driver distraction in tractor-trailers and motorcoach buses

Driver distraction has become an increasing concern over the last decade as portable technology has emerged and its presence while driving has become more common. Driver distraction occurs when inattention leads to a delay in recognition of information necessary to accomplish the driving task. Two recent studies were conducted using a naturalistic data collection method and analysis of driver distraction. The Commercial Motor Vehicle Driver Distraction study (Olson et al., 2009) was conducted using heavy truck data, and the Distraction and Drowsiness in Motorcoach Drivers study (Hammond et al., 2016) was conducted using motorcoach data. Data were collected continuously every time the instrumented vehicle was turned on and in motion. Data were reduced to identify safety-critical events such as crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Results show that 40% of truck crashes and 56% of motorcoach crashes had some kind of distracting behavior. Odds ratios were calculated on individual secondary tasks and analyses of variance (ANOVAs) were calculated on eye-glance data to determine the effects of eyes off the forward roadway. Fewer distractions were identified in the motorcoach data, most notably the use of handheld cell phones. This suggests that the 2010 ban on handheld phones has had a positive effect on decreasing cell phone use while driving.

Driver Distraction: Eye Glance Analysis and Conversation Workload

The objective of this project was to assess the risk of performing a secondary task while driving a commercial motor vehicle (CMV). The risk of conversation workload while driving a CMV was also assessed. Conversation workload is a proxy for cognitive distraction or the amount of mental workload associated with thinking about something other than the driving task. The data were collected from an existing naturalistic driving dataset. Naturalistic driving data records a driver performing his or her normal duties. The data were from 6,379 commercial trucks and buses during a 4-month period. The study found that talking to passenger(s) significantly increased the risk of a safety critical event (SCE). However, talking or listening on an electronic device while driving did not pose a significant risk. Drivers who looked away from the forward roadway close to the trigger point were more likely to be involved in an SCE. Talking time analyses showed that the longer a driver talked while driving, the less likely that driver was to be involved in an SCE. Results from the conversation workload analyses were inconclusive because there were not enough data for an assessment. Finally, the current study compared spurious and random baselines. Spurious baselines are recordings that are triggered by events not related to safety such as a vehicle traveling across railroad tracks. The study found that talking time and visual distraction plots for random and spurious baselines were similar. As a result, spurious baselines are acceptable for use in place of random baselines.