Design and Evaluation of Connected Vehicle Human Machine Interface for Highway Patrol PDF Download

Author: Biraj Subedi
Publisher:
ISBN:
Category : Automobile driving
Languages : en
Pages : 156

Get Book

Book Description
The Connected Vehicle Interface has the potential to revolutionize the concept of vehicle safety and mobility. Using the CV technology, equipped vehicles will be able to transmit and receive critical messages to other equipped vehicles and roadside units. Since the core of CV applications lies in alerting drivers about potential hazards, it is necessary to design a robust Human Machine Interface (HMI) that not only communicates critical messages to drivers in an easily readable and understandable format but also reduces its potential adverse impacts the drivers may experience. This study is focused on the development and assessment of a safe CV HMI for the WYDOT CV Pilot project. Although the pilot has more end-users, this study is focused on the development of a HMI for the Wyoming Highway Patrol (WHP). To achieve this objective, several studies were conducted including: 1) Development of an E-training module and a driving simulator experiments specific to the police patrol following similar procedures in the literature, utilizing expert reviews, and riding along with the WHP, 2) Evaluating the impacts of exposure of the police patrol to the CV HMI warnings in the driving simulator, 3) Using vehicle dynamics data and advanced Eye-tracking technology to evaluate the safety effectiveness of the WYDOT CV pilot and potential distraction introduced by the HMI. The first study included the development of an E-Training module and a driving simulator experiment. The challenge in developing this experiment was that it had to mimic the driving difficulty and had to include the most important police in-vehicle devices such as the Mobile Data Terminal, light and siren, and radio communications. To perform this, several rides along with the WHP were conducted and experts from the WHP were invited to the WyoSafeSim Driving Simulator Lab located at the University of Wyoming to test the scenarios several times before they were approved for experimentation. The second part of the study was the experiment itself where ten professional WHP troopers were invited. The scenarios developed aimed at assessing the effects of exposure to CV weather and work zone warnings on the behavior of the participants. First, the participants were asked to take an E-training which informed them about the different CV HMI applications, the various notifications and warnings, and the appropriate response/ action to each warning. For the driving simulator experiment, each participant was required to drive 8 scenarios: two Baseline scenarios without HMI and six scenarios with HMI and tested for different modalities. Vehicle dynamics data and eye tracking data were collected throughout the study using SimObserver® system and SmartEye® tracking system, respectively. Questionnaire surveys were performed before and after the experiment to collect the participants’ responses about the training itself and also to assess the impacts of exposure to the CV warnings. The third part of the study focused on evaluating the distraction potential of the CV HMI using the eye-tracking data. Glance duration, number of glances, gaze directions and other parameters were studied to evaluate the distraction generated by the CV HMI on police patrol. The participants of the study were Highway Patrol troopers and the nature of their job requires them to drive at high speeds and perform secondary tasks while driving to emergency scenes. They have a very different driving style than normal drivers. This had to be considered while interpreting the results. The findings of this study showed that CV applications have promising safety benefits. The participants were found to adhere more to the speed limits when provided with the CV warnings. They had better longitudinal and lateral control and smoother brake inputs. In the work zone advance warning area, the participants had lower speed variability. Also, it was observed that out of the three different CV modalities, the participants seemed to perform better when presented with Enlarged Icons and audio beeps which means that the notifications are presented on a full screen (enlarged) for a few seconds before they are minimized back to their final position and are accompanied by audio beeps. Regarding the distraction potential of the CV warning on Highway Patrol troopers, the eye tracking data suggested that the CV HMI might have introduced some distractions, especially, for the Small Icons with beeps modality. Similar to the vehicle dynamics, the best modality with the least distraction was also the one with Enlarged Icons and Beeps. The HMI glance durations induced for this modality were well within the typical range of in-vehicle devices suggested by the National Highway Traffic Safety Administration (NHTSA). The weather notifications had little to no distraction. However, work zone notifications seemed to induce longer and more frequent glances. This was because of the high frequency of notifications presented in a short duration of time for the work zone CV application. A revealed-preference survey showed that the participants found the CV notifications easier to read and understand. A few participants stated that the notifications were a little distracting. To see how the participants performed before and after a CV notification, a 5 s and 20 s before-after study was performed. This showed the immediate and long-term impact of the CV warning. The participants had better performance 5 s and 20 s after the notification compared to before the notification. Finally, the conclusions and lessons learned from the study were that designing an experiment for the highway patrol is much more difficult and requires in-depth knowledge about their complex driving environment and driving habits. The WHP have a driving behavior different from normal drivers so the training program needs to be designed and packaged specifically to the troopers. Also, since the troopers are highly skilled and confident about their driving skills, interpreting the results obtained from these studies is not straightforward and requires a comprehensive evaluation of the tiniest details. Key recommendations in this study are that it might be better if we could reduce the number of messages communicated in the work zone scenarios to reduce the information overload and potential driver distraction. Also, the best possible way to communicate the CV HMI notifications for highway patrol troopers seems to be with salient notification design with audio beeps instead of voice.