The current study examined specific aspects of human factors involved in driving a vehicle with a modified Drive-by-Wire (DBW) control system. A DBW system is an electro-mechanical system which controls the primary operations of a vehicle such as steering, acceleration, and braking using a controller such as a joystick. Designing a human interface system for a DBW system involves three main phases in the human factors design process namely user centric/ergonomic design conception, building a prototype and validating the prototype based on human factor considerations. The main objective and focus of this research is to conceptualize a more ergonomic DBW control interface based on human participant evaluations completed in a virtual reality driving simulator equipped with DBW controls. A secondary consideration is the gathering of data for the preparation of a future driver training course. The driving characteristics of 30 participants consisting of 3 different groups, ages 18-64, ages 65+,and people with disabilities were evaluated while driving with three different controllers: a joystick, a reduced effort steering wheel plus gas-brake lever combination (GB), and conventional vehicle controls (no Drive-by-Wire or NDBW), which included foot pedals and a steering wheel. The participants were required to drive through different scenarios such as mountain, city, and highway roads, in order to obtain user capabilities related to the steering, accelerating, braking, and compliance with traffic rules. To examine the steering lane data obtained from the simulator, percent error in lane deviation was calculated and presented against time. The results indicated that the joystick was the most difficult to drive on a straight road. The GB controller was easier to control on straight path maneuvers than the joystick, but it had an over-steering tendency at curves while the joystick was better at curves. To examine group differences of different variables, a one-way analysis of variance (ANOVA) was performed. Results showed that lane position variation, reaction time to brake, reaction distance and stopping distance had significance among variables such as maximum vehicle speed, improper space cushions, and missed turn signals, etc. Understanding the above characteristics can largely help in the development of a DBW interface system that heavily weighs human factors.

Virtual simulators have proven to be extremely effective tools for training individuals for tasks that might otherwise be cost-prohibitive, dangerous, or impractical. One advantage of using a virtual simulator is that it provides a safe environment for emergency scenarios. For many years the United States military and NASA have used simulators, including those affixed with drive-by-wire (DBW) controls, effectively and efficiently to train subjects in a variety of ways. A DBW system utilizes electrical circuits to actuate servo motors from a given input signal to achieve a desired output. In DBW systems the output is not directly mechanically connected to a control surface (steering, acceleration, deceleration, etc.); usually, the input controller is linked by electrical wires to a localized servo motor where direct control can be given. This project is aimed at developing a novel simulator for a future training program using DBW systems that caters specifically to individuals who currently use or will be using for the first time vehicle modifications in order to drive and maintain their independence. Many of these individuals use one or a combination of powered steering, acceleration, braking, or secondary DBW controls to drive. The simulator integrates a virtual training environment and advanced electronic vehicle interface technology (AEVIT) DBW controls (4-way joystick, gas-brake lever/small zero-effort steering wheel). In a 30 participant study of three groups (able-bodied individuals, elderly individuals, and individuals with disability), it was found that training with a DBW joystick steering system will require more instruction and simulator practice time than a gas-brake lever/small steering wheel combination (GB/S) to obtain a similar level of competency. Drivers using the joystick completed predetermined driving courses in longer times, at slower speeds, with more errors than the other DBW system. On average, the reaction time to a stopping signal was fastest with the gas-brake lever at 0.54 seconds. Reaction times for the standard vehicle controls and the joystick were 0.741 and 0.677 seconds respectively. It was noted that reaction times using DBW controls were shorter overall. When driving in traffic, drivers committed 4.9, 5.1, and 8.3 driving infractions per minute using standard vehicle controls (No Drive by Wire, (NDBW)), the gas/brake and steering system, and joystick system respectively. Most drivers felt that the GB/S system was easier to learn, easier to operate, safer, and more reliable than the joystick system.