ARL-TR-8265 ● JAN 2018

US Army Research Laboratory

Applied Robotics for Installations and Base 

Operations: User Perceptions of a Driverless 

Vehicle at Fort Bragg

by Kristin E Schaefer, Ashley N Foots, and Edward R Straub

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Destroy this report when it is no longer needed. Do not return it to the originator.
ARL-TR-8265 ● JAN 2018

US Army Research Laboratory

Applied Robotics for Installations and Base 

Operations: User Perceptions of a Driverless 

Vehicle at Fort Bragg

by Kristin E Schaefer and Ashley N Foots

Human Research and Engineering Directorate, ARL

Edward R Straub

The American Center for Mobility, Ypsilanti, Michigan

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1. REPORT DATE (DD-MM-YYYY)

January 2018

2. REPORT TYPE

Technical Report

3. DATES COVERED (From - To)

1 January 2016–30 October 2017

4. TITLE AND SUBTITLE

Applied Robotics for Installations and Base Operations: User Perceptions of a 

Driverless Vehicle at Fort Bragg

5a. CONTRACT NUMBER

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5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Kristin E Schaefer, Ashley N Foots, and Edward R Straub

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7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

US Army Research Laboratory

ATTN: RDRL-HRF-D

Aberdeen Proving Ground, MD 21005

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ARL-TR-8265

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

US Army Tank Automotive Research Development and Engineering Center

AMSRD-TAR-R

Warren, MI 48397 

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TARDEC

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12. DISTRIBUTION/AVAILABILITY STATEMENT

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13. SUPPLEMENTARY NOTES

Edward R Straub was previously the ARIBO program manager with the US Army Tank Automotive Research, Development 

and Engineering Center

14. ABSTRACT

The US Army Tank Automotive Research, Development and Engineering Center’s Applied Robotics for Installations and 

Base Operations (ARIBO) program at Fort Bragg, North Carolina, provided one of the first US-based living laboratories that 

allowed Soldiers the opportunity to directly interact with a driverless, robotic transport vehicle. Passengers and potential 

future passengers from the Warrior Transition Battalion (WTB) and Womack Area Medical Center were given the opportunity 

to provide user feedback during Phase 1 (driver operated) and Phase 2 (safety operator) of development of the vehicle. A total 

of 26 people including safety operators, passengers, bystanders, and Soldiers from the WTB provided feedback related to trust 

and acceptability of the vehicle autonomy, as well as design recommendations for increasing future passenger and pedestrian 

comfort and trust in the driverless transport vehicle. Overall findings suggest that even minimal exposure to robotic systems 

can increase positive ratings of trustworthiness and acceptability of the future autonomous capabilities of a driverless transport 

vehicle. However, the vehicle could benefit from a number of design features and capabilities to better communicate its 

decision-making processes and intent to passengers, pedestrians, and other road users.

15. SUBJECT TERMS

ARIBO, driverless vehicle, human–agent teaming, trust, user perceptions

16. SECURITY CLASSIFICATION OF:

17. LIMITATION

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44

19a. NAME OF RESPONSIBLE PERSON

Kristin E Schaefer

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410-278-5972

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Contents

List of Figures v

List of Tables v

1. Summary 1

2. Introduction: Applied Robotics for Installations and Base 

Operations 1

2.1 ARIBO Vehicle 5

2.2 Current Work 7

3. Background: Development of the Questionnaire 7

4. Methodology 8

4.1 Questionnaire 9

4.2 SurveyMonkey.com 9

4.3 Respondents 9

5. Results and Discussion 10

5.1 Trustworthiness 10

5.1.1 Perceived Intelligence and Autonomy 12

5.1.2 Perceived Trustworthiness 12

5.1.3 Perceived Use 13

5.1.4 Perceived Safety 14

5.2 Acceptability of Vehicle Autonomy 14

5.3 Recommendations for Vehicle Design 16

5.3.1 Rider Comfort 16

5.3.2 Pedestrian Comfort 17

5.3.3 Passenger Trust 17

5.3.4 Mobile Application or User Display Design 19

6. General Discussion 20
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6.1 Key Findings 21

6.2 Limitations 22

7. Conclusions 23

8. References 24

Appendix A. Previous Simulation Study Findings 27

Appendix B. Questionnaires 29

List of Symbols, Abbreviations, and Acronyms 35

Distribution List 36
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v

List of Figures

Fig. 1 ARIBO advertisement at Fort Bragg identifying vehicle pickup and 

drop-off locations.................................................................................. 3

Fig. 2 Planned vehicle routes between WTB and WAMC ............................. 4

Fig. 3 ARIBO driverless vehicle variants: a) 6-passenger and b) Americans 

with Disabilities Act (ADA)-compliant wheelchair accessible models 5

Fig. 4 Vehicle sensors ..................................................................................... 6

Fig. 5 a) Forward-facing and b) passenger-facing cameras............................ 6

Fig. 6 Placement of e-stop buttons.................................................................. 7

Fig. 7 Self-reported ridership numbers for Phase 1 and Phase 2 of vehicle 

operation ............................................................................................. 10

Fig. 8 Perceived trustworthiness ratings ....................................................... 11

List of Tables

Table 1 Passenger comfort feedback and vehicle design guidelines............... 16

Table 2 Design guidelines for pedestrian comfort and safety.......................... 17

Table 3 Design guidelines to increase passenger trust..................................... 18

Table 4 Design guidelines for a user display ................................................... 19
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INTENTIONALLY LEFT BLANK.
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1. Summary

This report provides user and potential user preferences and feedback associated 

with the design and engineering of a US Army driverless vehicle operating through 

the Warrior Transition Battalion (WTB) medical complex at Fort Bragg, North 

Carolina. Findings are derived from questionnaires addressing preferences related 

to perceived trustworthiness and capability of the autonomous system and can be 

used to inform design of future vehicle attributes and future research. The 

development and integration of this driverless vehicle was part of the US Army 

Tank Automotive Research, Development and Engineering Center (TARDEC)

Applied Robotics for Installations and Base Operations (ARIBO) program. It 

provided door-to-door transportation services between the WTB medical barracks 

and multiple drop-off locations at Womack Army Medical Center. Passengers, 

potential future passengers from WTB, and bystanders observing the ARIBO 

vehicle were given multiple opportunities to provide feedback during 2 phases of 

vehicle development: driver-operated (Phase 1) and safety-operator enabled 

(Phase 2). Overall findings were very positive toward preferences in the ARIBO 

driverless vehicle. This suggests that even minimal exposure to robotic systems can 

increase positive ratings of trustworthiness and acceptability of the future 

autonomous capabilities. A number of recommendations were on design features 

and capabilities to better improve decision-making and communicate intent to 

passengers, pedestrians, and other road users.

2. Introduction: Applied Robotics for Installations and Base 

Operations

The US Army TARDEC ARIBO program was designed as a series of pilot projects 

to coordinate technology development with on-base operational needs and 

applications to accelerate the adoption of autonomous vehicle technologies. In 

these pilots, users and nonusers had the opportunity to continuously interact with 

the technologies in a real-world, dynamic setting. The primary advantage of using 

operational military installations is access to semi-controlled and well-defined, 

bounded traffic environments combined with the flexibility to modify various 

elements of the physical infrastructure via the base’s chain of command (Straub 

2015).

Direct feedback on new technologies can be a challenge for the Army. Small 

Soldier groups are typically selected and asked to provide feedback on prototype 

technologies at research and development centers or carefully controlled field 

exercises in the case of products nearing production readiness. The ARIBO 
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program afforded researchers the opportunity to collect direct feedback from a 

randomized subset of users from within a specific geographic environment. In this 

manner researchers could evaluate feedback on technologies with more generalized 

relevance while still addressing warfighting-related issues such as communications, 

human–machine interaction, trust, and functional reliability, to name a few.

The Fort Bragg, North Carolina, ARIBO pilot project addressed the issue of 

autonomous personnel transit. This project was designed to provide on-demand 

transportation to wounded Soldiers traveling between the WTB barracks and the 

Womack Army Medical Center (WAMC). Although the program was designed for 

wounded Soldiers seeking medical treatment, the services were also available to 

Soldiers and civilians in the medical complex. These frequent, short-distance 

door-to-door trips* between the medical barracks and appointments at the medical 

center (Figs. 1 and 2) provided an environment to better understand the systemic 

impacts of driverless vehicle integration. 

 * The distances along the designated routes between the WTB barracks and WAMC are between about 1/3 and 3/4 mile. 

They negotiate mixed-use pedestrian sidewalks, cross a 4-lane divided road around WAMC, and negotiate congested parking 

lots and traffic circles at the WAMC entrances.
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Fig. 1 ARIBO advertisement at Fort Bragg identifying vehicle pickup and drop-off 

locations
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Fig. 2 Planned vehicle routes between WTB and WAMC

Research efforts included comparative analysis between human decisions and 

autonomy, operational efficiency impact, user and nonuser behavior, trust, and 

acceptance, as well as vehicle platform and technology development, engineering, 

maintenance, and reliability assessments. Functionally, the service provided a 

convenient mode of transportation and an opportunity to increase on-time 

appointment rates for Soldiers.

*

 

A phased introduction of autonomous control was implemented to ensure safe 

operations and a smooth increase in trust and confidence of the system. Phase 1 

consisted of a human driver-operated shuttle service. During this phase, vehicle 

data were collected for testing the underlying architecture and autonomy algorithms 

while a human driver controlled the vehicle. The purpose of this phase of 

development was 2-fold: first, because the vehicle was operated by a trained human 

 * Missed appointments account annually for about $1.2 million in opportunity cost.
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driver, we were able to evaluate the performance of the sensing and control systems 

in real-world conditions without increasing risk to any passengers; and second, we 

were able to evaluate the autonomy’s performance not only against real-world 

conditions, but compare performance and decision-making against the 

human-driven baseline using a recording scheme and automated analysis based on 

researcher-defined upper and lower limits of acceptable performance. Results of 

the analysis provided data for the decision to proceed to the next phase of the 

project. Phase 2 transitioned the role of the driver to that of a safety operator. A 

safety operator is trained in manual operations as well as the ability to transition 

between autonomous control mode and manual control mode. The safety operator 

sits in the driver’s seat, monitoring the status of the vehicle and the environment. 

The role of the safety operator was to only intervene with the vehicle’s autonomy 

in case of an emergency or potential vehicle error. 

2.1 ARIBO Vehicle

The vehicles stationed at Fort Bragg were Cushman Shuttle 6 low-speed electric 

vehicles(Fig. 3). These vehicles were capable of being optionally manned, meaning 

they could run either in fully autonomous, driverless mode or in manual, 

human-operated mode. Operations in human mode were no different from the 

normal operations of a Cushman Shuttle 6 one might encounter in any similar 

environment. 

Fig. 3 ARIBO driverless vehicle variants: a) 6-passenger and b) Americans with 

Disabilities Act (ADA)-compliant wheelchair accessible models

The autonomy package included a number of sensors to maintain situation 

awareness of the environment and operate within the dynamic nature of the medical 

complex (Fig. 4). Two Velodyne VLP-16 lidars mounted on the passenger-side 

front and driver-side rear provided a 360° horizontal and vertical field of view with 

16 line scans. These are the primary sensors used to detect objects around the 

vehicle and localize against curbs and other known landmarks. Two Hokuyo 

single-line lidar sensors were mounted to the front of the vehicle, one pointing 

 (a) (b)
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forward and one pointing down. The forward-facing Hokuyo served as a redundant 

obstacle detection sensor. The downward-facing sensor was used for identifying 

cross-track localization error by detecting lane markings and curbs. Two 

differential GPS antennas (one on the front center and the other on the rear center 

of the roof) provided redundant heading measurements and precision localization 

for the vehicle. Data radio antennas are used to communicate to the control station 

at the duty desk and with the reservation system. Automotive-grade radar sensors 

were added to the front sides of the vehicle to provide highly reliable detection of 

vehicle cross traffic at intersections. 

Fig. 4 Vehicle sensors

Cameras were positioned in the cab of the vehicle facing forward (Fig. 5a) and 

toward the passengers (Fig. 5b). The cameras were for passenger safety and to 

record the environment. Video data were recorded to Secure Digital cards on the 

cameras and to an on-board computer. The video was downloaded daily to a 

secured, encrypted computer accessible only to the researchers. 

Fig. 5 a) Forward-facing and b) passenger-facing cameras
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Five emergency stop (e-stop) buttons were available that disengage the autonomy 

system, bring the vehicle to a full stop, and engage the parking brake (Fig. 6). If 

activated at top speed (15 mph), the e-stop halted the vehicle in about 5.5 m. While 

in human-mode, the e-stop system was disengaged to eliminate the risk of it being 

engaged while a person is driving the shuttle. 

Fig. 6 Placement of e-stop buttons

2.2 Current Work

The research objective of the work described in this report was to collect user 

perception data associated with the perceived functionality and trustworthiness of 

the driverless vehicle during the first 2 phases of operation. Questionnaire data were 

anonymously collected from individuals (Soldiers and civilians) who may have 

been a passenger on or observed the ARIBO vehicles operating throughout the 

WTB medical complex. The purpose of this study was to expand on results from 

previous simulation experiments involving trust with the ARIBO driverless 

vehicles to more directly inform future autonomous vehicle and user interface 

designs required for effective human–robot teaming. 

3. Background: Development of the Questionnaire

The questionnaire items were built on previous research efforts to understand the 

relationship between trust, use, and robot design. As trust is essential for the 

successful function of any team (Groom and Nass 2007), the use of a robot is 

directly related to the human’s ability to place trust in that robot (Lussier et al.

2007). Hancock et al. (2011) identified through meta-analytic procedures that the 

primary moderator of human–robot trust development is the perception of the 

functional capabilities of the robot. However, the perceptions of the functional 

capabilities of the robot are not exhibited through actual behaviors alone. Duffy 

(2003) suggested the importance of the physical form of the robot, since it is the 
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8

compatibility of the design with the functional capability that increases acceptance 

of the robot. Further, Schaefer and colleagues (2012) found that individuals begin 

to make perceptions about the potential functionality of the robot (e.g., perceived 

level of automation and perceived robot intelligence), future outcomes with the 

robot (e.g., future use), and trustworthiness based on physical form, even depicted 

through a static image. Perceived intelligence, perceived level of automation, and 

intended future use were also highly correlated with trustworthiness ratings 

(Schaefer 2013). Therefore items specific to vehicle intelligence, control, use, 

safety, and trustworthiness as well as perceptions regarding specific driverless 

vehicle behaviors (e.g., navigation, obstacle detection and avoidance, and ability to 

follow road rules) were included in the development of the questionnaire. 

This questionnaire was also designed to provide recommendations specific to the 

design of this driverless vehicle that could potentially increase user comfort or 

engender trust in the vehicle. These items were based around previous research 

efforts and developed to benefit future research efforts specific to passengers and 

bystanders (Straub and Schaefer 2015). In an earlier simulation-based study, the 

respondents responded to open-ended questions specific to the vehicle design 

recommendations. These resulted in 4 main areas of missing feedback from the 

vehicle: navigation-related feedback, proximity-related information, system state, 

and passenger safety (see Appendix A for further details). The primary sentiment

of this prior research was that better shared situation awareness (i.e., the capability 

that the vehicle is aware of the physical environment and intends to respond 

appropriately) will engender trust and increase comfort in the vehicle (see Schaefer 

and Straub 2016). 

4. Methodology

Data were collected using a questionnaire. The questionnaire was available to both 

passengers and bystanders, also referred to as observers. A passenger was someone 

who received a ride from one point to another with no responsibility for the safety 

of others or the safe operation of the vehicle, whereas a bystander was someone 

who simply witnessed the vehicle in operational mode. Respondents included both 

Soldiers and civilians who previously scheduled a ride or those who were recruited 

by email from the battalion command. Respondents with scheduled rides 

automatically received an electronic version of the questionnaire following their 

ride. Others had the opportunity to complete either the electronic version via a web

link on their own time or the paper version in person immediately following the 

ride.
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4.1 Questionnaire

A 16-item author-created questionnaire was accessible via paper and pencil, as well 

as through SurveyMonkey.com, an online questionnaire software program that can 

be accessed from computer or smart phone. Appendix B includes 2 versions of the 

questionnaire for each phase of operation. Phase 1 items were worded in the future 

tense since a driver was operating the vehicle, while Phase 2 items were worded in 

the present tense since the vehicle was operating autonomously.

The first 4 items were designed to gather information about the respondent’s 

interaction with the vehicle, number of times as a passenger, first time filling out 

questionnaire, and if they had seen the vehicle operate autonomously (even if they 

never rode on the vehicle). Items 5–9 were 7-point Likert-type scale items related 

to questions used in previous work to identify perceptions about the trustworthiness 

of specific robots (Schaefer et al. 2012; Schaefer 2013). Items 10–13 were specific 

to the acceptability of the autonomy-enabled capabilities of the vehicle. The final 

open-ended questions were included to help direct future research. They included 

items that built on previous simulation research to identify specific design elements 

that could be used to increase comfort or engender trust while riding in the vehicle 

(Schaefer and Straub 2016), and increase comfort or engender trust for pedestrians 

(Straub and Schaefer 2015). No personally identifiable information was collected 

during this study. 

4.2 SurveyMonkey.com

Following all scheduled rides, respondents received an automatically generated 

email or were handed a flyer with the opportunity to complete the questionnaire via 

SurveyMonkey.com. SurveyMonkey.com was selected because it has been

approved for use by the US Army Research Laboratory’s Information Assurance 

Management Office. Backup paper and pencil versions of the questionnaire were 

also available. If a paper and pencil version was completed, then data were entered 

into the SurveyMonkey.com web link so that all of the data were complied.

4.3 Respondents

Respondents consisted of Soldiers and civilian personnel who 1) had scheduled 

transportation using the ARIBO driverless vehicle, 2) had observed the vehicle 

operating throughout the WTB medical complex, or 3) were members of the WTB 

that may or may not have seen the vehicle operating autonomously throughout the 

medical complex. A total of 26 responses were recorded. These included 7 

responses during Phase 1 (July–Oct 2016) during which the vehicle was driven by

a human operator and 19 responses during Phase 2 (Nov 2016–Aug 2017) when 
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the human driver relinquished driving control to the vehicle and assumed the role 

safety operator. 

5. Results and Discussion

The user preference questionnaires were completed by the driver or safety operator 

of the vehicle (N = 3), passengers (N = 16), bystanders or observers (N = 6), and 1 

Soldier in the WTB who did not report being a passenger or bystander. More 

specifically, out of the 26 responses, 7 people never rode the vehicle; 10 people had 

between 1 and 4 rides on the vehicle; 3 people rode the vehicle between 5 and 10 

times; and 6 people rode the vehicle more than 10 times (see Fig. 7). All 26 

respondents saw the vehicle operating in the area surrounding the WTB Medical 

Complex, but only 15 reported seeing the vehicle operate autonomously (2 from 

Phase 1 and 13 from Phase 2). The remainder of this section describes perceptions 

of trustworthiness, perceptions of autonomous vehicle capabilities, and 

recommendations for design guidelines to increase comfort and trust of both riders 

and pedestrians.

Fig. 7 Self-reported ridership numbers for Phase 1 and Phase 2 of vehicle operation

5.1 Trustworthiness

The questions to assess user perceptions of trustworthiness included ratings of 

perceived levels of vehicle intelligence, autonomy (i.e., the vehicle’s ability to 

0

1

2

3

4

5

6

Never rode First Ride 1-4 Rides 5-10 Rides More than 10

Rides

Number of Participants

Number of Rides on the Vehicle

Phase 1 Responses Phase 2 Responses
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control itself), trustworthiness, level of use, and safety. Twenty-four out of 26 

respondents answered these questions. Overall, results demonstrated positive 

agreement in support of perceived intelligence, perceived level of autonomy, and 

perceived trustworthiness of the ARIBO vehicle (Fig. 8). 

Fig. 8 Perceived trustworthiness ratings
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5.1.1 Perceived Intelligence and Autonomy

The first 2 items looked at perceived vehicle intelligence and perceived level of 

autonomy. Overall, both items were perceived positively by both passengers and 

bystanders. The percentage of participants that rated positive agreement of the 

perceived intelligence of the vehicle was 88.46% (3 somewhat agree, 5 agree, and 

15 strongly agree), while 84.62% of participants rated the perceived autonomy item 

positively (2 somewhat agree, 7 agree, and 13 strongly agree). Only one participant 

rated both items as neutral. This participant never rode or observed the vehicle 

operating autonomously. Later open-ended questions suggested that this participant 

also desired more feedback from the vehicle to quantify the vehicle’s decisionmaking processes and autonomous capabilities. These findings suggest that 

individuals want to believe that the vehicle will be intelligent and have the 

capability to function without the direct control of an operator, even ones that have 

never seen the vehicle operate autonomously as seen in responses from Phase 1 

operations. Results from Phase 2 operations suggest that individuals make 

determinations about the level of vehicle intelligence and autonomy even though 

the vehicle was not designed to have any directed feedback as to the specific 

intelligence architecture. This is important to the Army because it suggests 

perceptions about the driverless vehicle’s ability are based on relatively few 

performance variables. Additionally, the Army spends more every year to run its 

installations than just about anything other than personnel costs. User and potential 

user perceptions are important to the acceptance of driverless vehicles. Automation 

can improve efficiencies and safe operations on bases and the degree to which it is 

widely adopted can have a positive impact on budgets and operational performance. 

Diving further into the factors that lead to these few perceptions of ability or 

competency of such vehicles can help developers focus on those elements most 

important to Soldiers in the field.

5.1.2 Perceived Trustworthiness

Self-report ratings of vehicle trustworthiness were positively rated such that 

80.77% of respondents rated the perceived trustworthiness positively (2 somewhat 

agree, 8 agree, and 11 strongly agree). There were no negative ratings, and only 2 

neutral ratings. Out of the 2 neutral ratings, one respondent had never ridden or 

observed the vehicle operating autonomously, and the second had previously ridden 

the vehicle 5–10 times during Phase 1 (operated by the human driver), but had seen 

it operate autonomously as an observer.
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These overall positive findings could directly support the current design and 

functional capabilities of the vehicle for short duration travel, such that the current 

design features and capabilities provided adequate situation awareness needed to 

calibrate trust in the vehicle with minimal prior interaction. However, these positive 

trustworthiness ratings may also be influenced by the larger system including the 

human driver or safety operator onboard the vehicle, as well as command support 

and encouragement of ridership with the ARIBO driverless vehicle at WAMC. In 

addition, the 2 neutral responses suggest some individuals may need to physically 

see, experience, and understand the capabilities of the system before putting blind 

faith in the system.

5.1.3 Perceived Use 

The perceived use question asked respondents if they felt the vehicle would be used 

regularly by the Soldiers at WTB, not just when operated by a driver or safety 

operator but also when the operator was removed from the vehicle. While there was 

slightly more divergence in responses, just under 70% of respondents rated the 

perceived use positively (6 somewhat agree, 5 agree, 7 strongly agree). These data

suggest that to some degree Soldiers and civilians believe their fellows will value 

point-to-point, scheduled, and on-demand driverless transportation. However, there 

was some divergence in perceived amount of vehicle use: 2 strongly disagreed with 

this item, 1 disagreed, and 3 were neutral. 

Respondents with these negative ratings for perceived use had limited to no prior 

interaction with the vehicle during Phase 1 or Phase 2 of operations and had some 

limited knowledge or understanding of how the vehicle could or would operate 

safely without a driver. This supports the need for increased access in the Army to 

autonomous vehicle technologies to increase understanding and trust to better 

support appropriate use of future robotic systems. 

The 3 neutral ratings came from 2 people on their first ride and 1 who had ridden 

the vehicle more than 10 times. While some undirected feedback supported that 

these respondents would be willing to use the vehicle again, there was some 

hesitation on rating how others would use the vehicle. This was in part due to the 

limited knowledge of the larger population base regarding vehicle availability, 

limited hours of operation, and observations of vehicle runs without passengers. In 

addition, these data do not control for the presence of the safety operator, making 

it difficult to determine if respondents would recommend use of the vehicle with 

the safety operator behind the wheel although our data (Section 5.1.1) on 

trustworthiness suggests they would. Once the technology reliably and safely 

allows, future research should examine these questions without the presence of a 

safety operator.
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5.1.4 Perceived Safety

Ratings for perceived safety were slightly higher with 76.92% rating perceived 

safety positively (3 somewhat agree, 6 agree, and 11 strongly agree). While it is 

possible that these ratings support the design and capabilities of the system to 

promote safety, it is also possible that some of these ratings were not based on 

interaction or observation of the vehicle but rather from the larger assumption that 

the Army would not allow vehicles on the road that were not safe. This supports 

the idea that trust in autonomy has larger implications than just improving 

engineering systems alone. This type of trust is related to the vehicle, but also the 

larger Army and support of the command. Future work would need to be conducted 

to address this more fully.

These 4 respondents had either neutral safety ratings (N = 3) or felt the vehicle was 

unsafe (N = 1). All these respondents had limited interactions with the autonomy 

features and capabilities of this vehicle. Therefore, it is possible to speculate that 

these evaluations may have been based on some bias or preconception of the 

technology, or influenced by the safety performance of the human driver. While 

additional research is needed to determine the specific reasoning behind these 

ratings, this finding supports the Army’s need for increased access and exposure to 

robotic technologies. This is important to advancing shared situation awareness and 

understanding of future robotic capabilities to appropriately calibrate trust and 

promote effective use. 

5.2 Acceptability of Vehicle Autonomy

Over the course of 3 years, the ARIBO vehicle has demonstrated the capability to 

effectively navigate through the medical complex; detect and avoid obstacles, other 

road users, and pedestrians; and follow traffic rules while operating in fully 

functioning driverless operations (with a safety operator present). However, actual 

system capabilities may not directly match perceived capabilities from passengers 

or bystanders with limited knowledge of the functional capabilities of the vehicle. 

Therefore, respondents assessed the perceived acceptability of the vehicle’s 

autonomous navigation, obstacle detection and obstacle avoidance (ODOA), and 

the ability to follow traffic rules. While respondents may have never seen or 

personally interacted with the vehicle during autonomous operations, the results 

provide some insight into the user population’s perceptions of future autonomy.

Respondents rated 3 capabilities: autonomous navigation, ODOA, and following 

road rules. Overall, 80.77% of the respondents found the autonomous vehicle 

navigation capabilities to be acceptable, while 73.08% found the ODOA and ability 
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15

to follow road rules to be acceptable. Furthermore, there were no significant 

differences between respondents who had little to no interaction with the ARIBO 

vehicle and those who were passengers during driverless operations. This suggests 

that overall, individuals support the current and future capabilities of the vehicle.

However, there is still room to advance the engineering and design needed for 

increased understanding and support of these vehicle capabilities. The additional 

negative and neutral ratings on these 3 items provide some insight into the types of 

individuals and amount of information access that may be needed to increase 

acceptability ratings of these types of vehicle autonomy. For example, 3 individuals 

had neutral (N = 1) or slightly unacceptable (N = 2) ratings regarding the 

navigation-based autonomy. These respondents either had limited prior interaction 

with the vehicle or had concerns about the safety-based navigation and 

recommended more direct vehicle feedback for passengers. In addition, the 

acceptability ratings of the ODOA-based autonomy included 3 neutral ratings, a 

slightly unacceptable rating, and an unacceptable rating. Similarly, all these 

respondents had limited prior interactions with the autonomous capabilities of the 

vehicle. This finding suggests that perceived capabilities will be enhanced either 

through increased access to robotic systems through communication of capabilities 

or actual interaction. The acceptability of the vehicle to follow traffic rules ratings 

included 3 neutral and 1 slightly unacceptable rating. Most of these respondents 

had limited or no prior interaction with the vehicle, suggesting that similar to the 

above finding, increased communication of capabilities or interaction with the 

system can increase understanding of the capabilities. Further, a respondent was a 

prior passenger on the vehicle but had concerns of the safety of the vehicle 

following concerns related to right-of-way behaviors throughout an intersection. 

This suggests that there may be a benefit to share more information or feedback 

during an interaction to better communicate vehicle intent. 

Overall, the data above indicate confidence in the vehicle’s autonomy, navigation, 

and ability to detect and avoid obstacles. This suggests that autonomous vehicle 

performance capable of approximating human performance is what passengers and 

bystanders expect of autonomous vehicles. Further findings suggest that there may 

be a subset of people who have limited exposure to autonomy who would benefit 

from increased exposure and feedback of autonomous capabilities for navigation, 

ODOA, and the capability to follow road rules. 
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16

5.3 Recommendations for Vehicle Design

All respondents were given the opportunity to provide design feedback and 

recommendations related to rider comfort, pedestrian comfort, rider trust, and a 

future user display design. 

5.3.1 Rider Comfort 

All respondents were asked to provide open-ended recommendations for the future 

design of the vehicle to increase comfort of passengers onboard the vehicle. Out of

the 26 respondents, only 6 provided directed comments for enhancing passenger 

comfort. The remaining 20 respondents left this item blank, specifically denoted 

that they had no direct feedback, or stated the vehicle provided adequate passenger 

comfort for the short duration of the trip. Table 1 lists the specific feedback and 

comments. 

Table 1 Passenger comfort feedback and vehicle design guidelines

Number of 

comments Specific feedback

2 Second row has limited leg room for tall passengers or those with severe injuries

1 Seats are uncomfortable, especially for those with injuries

1 Need seat beltsa

2 Need feedback from vehicle or signage to communicate vehicle capabilities when 

interacting with other road users in intersections, parking lots, and on roadway 

a All seats were instrumented with seatbelts. Recommendation came from person who never rode in 

the vehicle.

Two major types of feedback included design recommendations for physical 

comfort and for providing passenger safety. The first was directed at 

accommodations for this specific use population, including more comfortable seats 

and extended leg room. This accommodation was considered in the mobile 

application when scheduling a ride; a wheelchair-accessible vehicle with extended 

leg room was available for transport and could be selected at the time of reservation. 

The second design recommendation was specific to both physical safety and 

perceived safety. Seatbelts were already included for every seat on the vehicles. In 

addition, the need for communication to alleviate discomfort and mitigate 

uncertainty is paramount for increasing passenger comfort in the vehicle, especially 

when the safety operator is removed from the driver’s seat. Future vehicle design 

considerations and research for driverless shuttles should address mechanisms to 

effectively communicate safety options available to passengers. Passenger comfort 

and safety features are clearly important to passengers and potential passengers of 

driverless transport vehicles. Features and tasks requiring action on the part of 
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17

passengers (e.g., fasten seat belts) should be clear from early in the reservation 

process to embarkation through transport and debarkation. 

5.3.2 Pedestrian Comfort

Since these vehicles operate on both roadways and sidewalks, all respondents were 

asked to provide open-ended recommendations for the future design of the vehicle 

to increase comfort of pedestrians near the vehicle. Out of the 26 respondents, 8 

respondents provided feedback related to pedestrian comfort. The remaining 18 

respondents left this item blank, specifically denoted that they had no direct 

feedback, or felt the vehicle had no direct effect on pedestrians. Table 2 provides 

specific feedback and comments. 

Table 2 Design guidelines for pedestrian comfort and safety

Number of 

comments Specific feedback

4 Addition of audible alerts or warnings

1 Use of a flashing light so others can see the AIRBO cominga

1 Larger vehicle to increase pedestrian awareness 

1 Inclusion of a large, legible sign onboard the vehicle stating that vehicle operates 

safely without a driver

1 Some type of warning is needed when approaching pedestrians 

a Both vehicles were instrumented with a yellow safety light.

All design recommendations were specific to providing additional pedestrian 

safety. Specifically, the respondents were interested in providing pedestrians with 

awareness of the vehicle’s presence and capabilities through means such as signage, 

or audible alerts or warnings. Some examples included a verbal acknowledgement 

of when the vehicle was paused for a pedestrian or a horn beep to let a pedestrian 

know the vehicle was waiting on them. Future research and vehicle design should 

examine common communication techniques used to communicate with 

able-bodied adult pedestrians, children, and pedestrians with disabilities (e.g., blind 

or deaf), as well as the implication of regional norms or variations in order to assess 

different types of alerts and warnings that could be used to effectively communicate 

vehicle intent with pedestrians. 

5.3.3 Passenger Trust

All respondents were asked to provide recommendations for the design of the 

vehicle that would increase future rider trust in the vehicle, especially once the 

safety operator was removed from the driver’s seat. Out of the 26 respondents, 5 

provided design guidance on improving rider trust in the driverless vehicle. The 

remaining 21 respondents left the item blank, directly stated no guidelines, or 
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18

specifically pointed out that current design did not lessen trust in the vehicle. All 5 

of the comments were related to passenger awareness and ways to improve the 

passengers’ perception of safety in terms of error prevention and mitigation, such 

as means for adapting control allocation. Table 3 provides specific feedback and 

comments. 

Table 3 Design guidelines to increase passenger trust

Number of 

comments Specific feedback

1 Change outward vehicle appearance (e.g., bright color) to increase nonuser 

awareness 

1 Include eye-catching signage of features onboard the vehicle 

1 A communication system with a human for emergencies

1 Include an emergency stop button that the passengers could pressa

1 Capability to take control of the vehicle if unsafe

a Both vehicles were instrumented with multiple emergency stop buttons (see Fig. 6). 

Development of appropriate vehicle autonomy and trust requires an understanding 

of how driverless vehicles and other road users will mutually interact during shared 

operations (Straub and Schaefer in press). The technology is not yet available for 

the general population to be familiar with autonomous vehicles. Access to these 

types of technologies will increase understanding and experience with the 

technology, which may lead to an increase in trust. It is difficult for people to trust 

something they do not understand or do not know about. Results from this openended feedback suggested that design guidelines should include both indirect and 

direct error prevention and mitigation strategies.

Specific form-based features can support (or hinder) expectations of vehicle 

capabilities (Groom and Nass 2007). For example, a feature such as changing the 

outward appearance of the vehicle to increase other road-user awareness indirectly 

mitigates issues that could occur when sharing the roadway, thus reducing the 

possibility of misunderstanding vehicle intent. Similarly, onboard signage of 

vehicle features or a communication system with person monitoring the system can 

increase the passenger’s situation awareness of what the vehicle can and should be 

doing in certain situations. 

Moreover, once the safety operator is removed from the driver’s seat, there will be 

questions as to how passengers will be able to interact with vehicle and concern for 

how to respond in case of errors. At present, passengers have limited familiarity 

with the ARIBO vehicle and there is limited feedback onboard to communicate its 

state, intended behaviors, or awareness of the environment including pedestrian or 

vehicle awareness. This could directly impact passenger’s comfort and trust and 
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19

directly impact the need to take control of the vehicle in what could be perceived 

to be a harmful situation. An example of a harmful situation was when the 

autonomous vehicle was in an intersection and another vehicle was approaching, 

there was no indicating that the other vehicle was sensed. Therefore, specific design 

recommendations for direct error mitigation included the capabilities to take over 

control either through use of emergency stop buttons or full manual controls. This 

leads to a larger issue of not just having these design features available, but 

appropriate use of these features and responsibility. Appropriate control allocation 

can only be established when the riders and vehicle have developed a shared 

situation awareness (Schaefer et al. 2016). This leads directly into the benefits of 

the inclusion of a mobile application or user display to communicate vehicle intent 

to the passenger and adequate warnings in situations that may require human 

intervention.

5.3.4 Mobile Application or User Display Design

All respondents were asked if a cell phone application or onboard user display 

would be beneficial to provide vehicle information to riders. Out of the 26 

respondents, 16 said yes, 6 said no, and 4 did not respond. In addition, 7 respondents 

provided suggestions for the design guidelines relating to navigation-specific 

feedback, error reporting, and contact information. These suggestions and 

comments ranged from simple things such as posting hours of operation and contact 

information, to having the vehicle provide specific route information and 

verification. Table 4 provides specific feedback and comments that could be 

applied to either a cell phone application or onboard user display. 

Table 4 Design guidelines for a user display

Number of 

comments Specific feedback

4

Navigation-specific feedback

• Estimated time of arrival

• Notification of change in vehicle behaviors (e.g., preparation to stop, 

turning, destination arrival)

• Easy to read route (e.g., stop locations; similar to GPS navigation system)

• Length of time until the vehicle arrives at the pickup location

3

Error reporting

• Interactive display for reporting issues, errors, and rider concerns

• Denote number of accidents to date or days without errors

• Provide safety-related information and comments

1 Contact information

• Provide contact information (e.g., phone numbers and hours of operation)
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20

Interestingly, top design considerations to advance passenger trust in the vehicle 

had less to do with vehicle autonomy than they did with vehicle functional 

performance. In other words, being notified of information such as estimated time 

of arrival and route information is similar to information one might either ask a 

human driver or be expected to have available in a vehicle driven by a human. Even 

a relatively simple suggestion such as posting contact information speaks to trust 

development in the autonomous system. It suggests passengers want a human 

fallback option to call in case of error or if they become confused and need some 

aspect of the system explained to them, especially if an error is reported and the 

passenger has no idea what to do next. Teasing out the reasons behind this apparent 

desire for human contact is an area of future research. Additionally, it will be 

important to understand the point at which trust in the system supplants this need. 

6. General Discussion

When a passenger gets into a vehicle driven by a human, it is easy for them to put 

themselves in the driver’s place. This is a familiar interaction for most passengers, 

and therefore one that contributes to their perceptions of safety as a passenger. It is 

assumed that the driver is using sight, sound, and experience to pay the right amount 

of attention to the road and behaving appropriately. Similarly, when a driver 

transitions into a role of a safety operator, it is also assumed that there is an extra 

level of safety in place since the operator is ultimately responsible for the 

passengers and bystanders. When the vehicle is controlling itself, there is no similar 

connection. Passengers have only their general preconceptions of autonomous 

systems to assess the appropriateness of decisions. At best, the average passenger 

has only a limited understanding of the sensor systems the vehicle is using to 

perceive and understand its environment, until they have ample opportunity to 

interact with the system. Most of the questionnaire responses in our study point to 

the fact that observation and interaction with autonomous vehicles can increase 

feelings of trustworthiness and perceived understanding of the actual autonomous 

capabilities of the vehicle. However, for those with a limited understanding of the 

autonomy, there is a need to move beyond just advancing the engineering 

capabilities. To facilitate interaction and an efficient transportation system, 

passengers and bystanders need to appropriately trust in automated driverless

vehicle’s ability to operate safely and abide by norms and generally accepted rules 

of the road. To do this they need to be able to understand how the vehicle operates 

or how to gather information about its operation from before or during interaction. 

In addition, open-ended feedback from respondents suggests the need for a 

human-in-the-loop, especially when the safety operator is removed from the 

vehicle. 
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21

The general public, represented in this study by a random sample of Soldiers and 

civilians in and around the WTB complex, has very little direct experience with 

autonomous technologies. Expectations and perceptions after direct experience 

affected preconceptions in a generally positive way. Vehicle design should include 

intuitive, universal interfaces focused on providing information passengers and 

pedestrians could use to make a connection to the vehicle. This connection and 

demonstrated reliability will improve trust and overall performance in mixed traffic 

environments.

6.1 Key Findings

There were 7 key findings from this work.

1) Most people had positive trust-related ratings despite whether or not they 

have had previous direct interaction with the vehicle’s autonomy. 

2) People believed that the autonomous capabilities of the ARIBO were

acceptable or would be in the future, regardless of whether or not they had

seen the vehicle operate autonomously or not. 

3) The small group of individuals with lower perceptions of trustworthiness

and acceptability were found to have a minimal understanding the system, 

suggesting that more detail or information prior to or during the ride could 

increase feelings of safety and security. 

4) Recommended design features to improve passenger comfort were specific 

to the potential needs of the wounded Soldier population who may use this 

vehicle and the general safety of all riders. These included more 

comfortable seats, extended leg room, safety belts, and effective 

communication of safety features and options to all passengers.

5) Recommended design features to increase pedestrian comfort were specific 

to pedestrian safety awareness. While the current vehicle capabilities only 

had the vehicle slow down, or stop and wait for pedestrians, feedback 

suggests that additional alerts or warnings (e.g., verbal acknowledgment 

when vehicle is paused for pedestrian, horn sounding to let pedestrian know 

the vehicle is waiting, or signage explaining that this is a driverless vehicle) 

would improve vehicle–pedestrian interaction. 

6) Recommended design features to increase passenger trust in the vehicle 

were specific to perceptions of safety, specifically error prevention and 

mitigation. Specific features, such as vehicle size, coloration, or signage, 

can communicate to other road users that the vehicle is a driverless vehicle,
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22

thus impacting vehicle-to-vehicle interaction. In addition, it is essential to 

identify methods for determining when and how a passenger can adapt 

control allocation and respond to high-risk situations once the operator is 

removed from the vehicle.

7) The system would benefit from a user display (e.g., mobile application or 

onboard display) to communicate vehicle awareness and actions, including 

but not limited to navigation-specific feedback (e.g., estimated time of 

arrival, changes in behaviors, routes, arrival time), error reporting (e.g., 

means to report issues or errors, number of errors or accidents, 

safety-related information), and a means to connect to a human monitor.

6.2 Limitations

There were 2 potential limitations to this work. 

1) Limited Ridership: Despite the fact that WTB averages more than 700 

appointments at WAMC each week and that the barracks are capable of 

housing more than 600 Soldiers at a given time, there was limited response 

from the WTB Soldiers. This was in part impacted by a limited number of 

scheduled riders using the ARIBO Mobile application, including 12 

scheduled riders with 112 rides during Phase 1 of operation and 5 scheduled 

riders with a total of 15 rides during Phase 2 of operation. In addition to the 

above riders, unscheduled riders and Soldiers who responded to email 

requests for feedback made up most of the respondents. However, specifics 

as to the amount of total riders and rides were not recorded. These 

limitations in sample size limited the type of statistical analysis that could 

be conducted and directly influenced the potential outcomes of this work. 

2) Trust: Subjective assessment of trust in an autonomous vehicle is not 

restricted to the engineering technologies of the vehicle alone. Trust is 

assessed with respect to a whole system. For the ARIBO vehicle this system 

included a driver or safety operator, the users or potential users at the WTB 

complex, and the direct support of the command staff for vehicle integration 

and use. Therefore, it is possible that the respondents assumed that the larger 

Army would not allow a technology that was not safe or function 

appropriately to be used by the WTB Soldiers. Therefore, based on the 

current questionnaire design, it is not possible to vet the trust-related 

responses without additional follow-up research. 
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23

7. Conclusions

Although this user perception study had far less participation than anticipated, a 

number of areas for future research were highlighted that are relevant to robotic 

vehicle deployment in the Army. In general, individuals have limited or no 

experience with robotic technologies, such as driverless vehicles, but minimal 

exposure to these technologies can positively impact trust ratings, as found in the 

study. This finding could be specific to the vehicle capabilities and design for the 

use of personnel transport, but could also be influenced by the larger operations 

space. For example, trust in the vehicle could be directly influenced by direct access 

to the driver or safety operator. How this trust changes when a safety operator is 

removed from the vehicle is a future line of research. These findings may have also 

been influenced by reputation of the larger Army such that individuals may feel 

that the Army would not allow nor encourage ridership if the design and equipment 

were not safe—this is a thought that will have to be tested with data collected in the 

future. 

While the ARIBO shuttle vehicles were rated positively across the trust and 

acceptability questions, specific design guidelines were provided to improve trust 

and comfort by passengers, pedestrians, and other road users. Most of the feedback 

supported the need for increased communication either prior to use or during 

operations. Increased communication for passengers and pedestrians would include 

education on the vehicles technology and capabilities. Increased communication 

for vehicle-to-vehicle interactions would include ways of letting other vehicles 

know that the vehicle had detected the other vehicle and its plan of action. Overall, 

these findings support the advancement of robotic technology and start to show that 

such technology may provide major advantages for the Army in the area of 

manned–unmanned teaming. 
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24

8. References

Duffy BR. Anthropomorphism and the social robot. Robotics and Autonomous 

Systems. 2003;42:177–190.

Groom V, Nass C. Can robots be teammates? Benchmarks in human-robot teams. 

Interaction Studies. 2007;8(3):483–500.

Hancock PA, Billings DR, Schaefer KE, Chen JYC, Parasuraman R, de Visser E.

A meta-analysis of factors affecting trust in human-robot interaction. Human 

Factors. 2011;53(5):517–527.

Lussier B, Gallien M, Guiochet J. Fault tolerant planning for critical robots. 

Proceedings of the 37th Annual IEEE/IFIP International Conference on 

Dependable Systems and Networks; 2007 June 25–28; Edinburgh, UK.

Washington (DC): IEEE Computer Society; c2007. p. 144–153.

Schaefer KE. The perception and measurement of human-robot trust [dissertation]. 

[Orlando (FL)]: University of Central Florida; 2013.

Schaefer KE, Brewer R, Putney J, Mottern E, Barghout J, Straub ER. Relinquishing 

manual control: collaboration requires the capability to understand robot 

intent. Proceedings of the 9th International Workshop on Collaborative 

Robotics and Human Robot Interaction; 2016 Oct 31–Nov 4; Orlando, FL. 

2016. Los Alamitos (CA): IEEE Computer Society; c2016. p. 359–366.

Schaefer KE, Sanders TL, Yordon RE, Billings DR, Hancock PA. Classification of 

robot form: factors predicting perceived trustworthiness. Proceedings of the 

56th Annual Human Factors and Ergonomics Society; 2012 Oct 22–26; 

Boston, MA. Santa Monica (CA): Human Factors and Ergonomics Society, 

Inc.; 2012. p. 1548–1552.

Schaefer KE, Straub E. Will passengers trust driverless vehicles? Removing the 

steering wheel and pedals. Proceedings of the 6th Annual IEEE International 

Multi-Disciplinary Conference on Cognitive Methods in Situation Awareness 

and Decision Support (CogSIMA); 2016 Mar 21–25; San Diego, CA.

Straub E. The impact of autonomy-enabled vehicles and system controls on nonusers in semi-controlled environments. Proceedings of the NDIA Ground 

Vehicle Systems Engineering and Technology Symposium; 2015 Aug 4–6; 

Novi, MI. 
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Straub ER, Schaefer KE. Applied robotics for installations and base operations 

(ARIBO): passenger trust and non-user impact. Unmanned Systems 

Integration Workshop and Technical Exchange. Dahlgren (VA): Naval 

Surface Warfare Center; 2015.

Straub ER, Schaefer KE. It takes two to tango: Automated vehicles and human 

beings do the dance of driving – four social considerations for policy. 

Transportation Research Part A, Special Issue on Autonomous Vehicle Policy. 

In press. 
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INTENTIONALLY LEFT BLANK.
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Appendix A. Previous Simulation Study Findings
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Previous findings recommended 4 areas of design recommendations to increase 

situation awareness to engender trust in the Applied Robotics for Installations and 

Base Operation (ARIBO) vehicle.

1

1. External Environmental Awareness: Passenger wants to know that 

the vehicle knows what is going on in the environment

• 13 out of 20 participants provided 14 design recommendations

• Examples include obstacle detection indicators on an onboard 

user display, response time indicator for vehicle behavior, and 

visual/auditory pedestrian safety warnings and alerts. 

2. Navigation-based Autonomy: Passenger wants to know where the 

vehicle is currently located and where it is going

• 15 out of 20 participants provided 26 recommendations

• Examples include: pickup and drop-off locations on an onboard 

or mobile display, estimated time of arrival indicator, and 

visual indicators such as turn signals to communicate changes 

in vehicle direction 

3. System Awareness: Passenger wants to know that the vehicle is aware 

of its current state

• 9 out of 20 participants provided 11 recommendations

• Examples include activation lights, speed indicator, display 

that shows changes in vehicle behaviors, vehicle health status 

such as fuel or battery life, and countdown until a specific 

vehicle action

4. Passenger Awareness and Safety: Passenger wants to make sure the 

vehicle is aware of those onboard

• 6 participants provided 7 recommendations

• Examples include auditory or visual safe boarding or exiting 

alerts, notice of engagement of safety features, weather 

indicators 

 1 Schaefer KE, Brewer R, Putney J, Mottern E, Barghout J, Straub ER. Relinquishing manual 

control: collaboration requires the capability to understand robot intent. Proceedings of the 9th

International Workshop on Collaborative Robotics and Human Robot Interaction; 2016 Oct 31–Nov 

4; Orlando, FL. 2016. Los Alamitos (CA): IEEE Computer Society; c2016. p. 359–366.
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Appendix B. Questionnaires 

 

This appendix appears in its original form, without editorial change.
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30

ARIBO Driverless Vehicle: Phase 1 Questionnaire

1. Circle the most appropriate description of your interaction with the vehicle:

Driver Passenger Observer (not riding on vehicle)

2. How many times have you been a passenger on this vehicle? _______________

3. Is this your first time filling out this questionnaire (circle one)?

Yes No

4. Have you seen the vehicle operate autonomously without a driver controlling it (circle 

one)? 

Yes No

Directions: Please rate your agreement with each item based on your beliefs about the 

FUTURE capabilities with the vehicle.

5. The vehicle will be intelligent (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

6. The vehicle will control itself (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

7. The vehicle will be used regularly by Soldiers at Ft. Bragg (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

8. The vehicle will be safe (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

9. The vehicle will be trustworthy (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree
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Directions: Please rate acceptability of each item based on your beliefs about the FUTURE 

capabilities of the vehicle.

10. The vehicle will be able to navigate throughout the medical facilities without human 

intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable

11. The vehicle will be able to avoid other vehicles, obstacles, and pedestrians without 

human intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable

12. The vehicle will be able to respond to traffic rules (e.g., road signs, road rules) without 

human intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable

Directions: The following questions are open-ended questions that will allow you provide 

recommendations specific to the future design of the vehicle. 

13. Please provide any recommendations for the design of the vehicle in order to increase the 

comfort of a passenger onboard. 

14. Please provide any recommendations for the design of the vehicle in order to increase the 

comfort of nearby pedestrians.

15. Please provide any recommendations for the design of the vehicle that would increase 

trust in the vehicle. 

16. Should we provide passengers with a cell phone app or onboard display that provides 

vehicle information (circle one)? 

Yes No
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32

ARIBO Driverless Vehicle: Phase 2 Questionnaire

1. Circle the most appropriate description of your interaction with the vehicle:

Safety Operator Passenger Observer (not riding on vehicle) Other

2. How many times have you been a passenger on this vehicle? _______________

3. Is this your first time filling out this questionnaire (circle one)?

Yes No

4. Have you seen the vehicle operate autonomously without a driver controlling it (circle 

one)? 

Yes No

Directions: Please rate your agreement with each item based on your PAST/CURRENT 

experiences with the vehicle.

5. The vehicle is intelligent (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

6. The vehicle controls itself (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

7. The vehicle will be used regularly by Soldiers at Ft. Bragg (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

8. The vehicle is safe (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

9. The vehicle is trustworthy (circle one)

Strongly 

Disagree

Disagree Somewhat 

Disagree

Neither 

Agree nor 

Disagree

Somewhat 

Agree

Agree Strongly 

Agree

Directions: Please rate acceptability of each item based on your PAST/CURRENT experiences 

with the vehicle.

10. The vehicle navigates throughout the medical facilities without human intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable
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33

11. The vehicle avoids other vehicles, obstacles, and pedestrians without human intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable

12. The vehicle responds to traffic rules (e.g., road signs, road rules) without human 

intervention.

Totally 

Unacceptable

Unacceptable Slightly 

Unacceptable

Neutral Slightly 

Acceptable

Acceptable Perfectly 

Acceptable

Directions: The following questions are open-ended questions that will allow you provide 

recommendations specific to the future design of the vehicle. 

13. Please provide any recommendations for the design of the vehicle in order to increase the 

comfort of a passenger onboard. 

14. Please provide any recommendations for the design of the vehicle in order to increase the 

comfort of nearby pedestrians.

15. Please provide any recommendations for the design of the vehicle that would increase 

trust in the vehicle. 

16. Should we provide passengers with a cell phone app or onboard display that provides 

vehicle information (circle one)? 

Yes No

If so, what type of information should be provided to help increase a passenger’s trust in 

the vehicle?
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INTENTIONALLY LEFT BLANK.
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35

List of Symbols, Abbreviations, and Acronyms

ARIBO Applied Robotics for Installations and Base Operations

GPS global positioning system

ODOA obstacle detection and obstacle avoidance

TARDEC US Army Tank Automotive Research, Development and 

Engineering Center

WAMC Womack Army Medical Center

WTB Warrior Transition Battalion
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1 DEFENSE TECHNICAL

(PDF) INFORMATION CTR

DTIC OCA

2 DIR ARL

(PDF) IMAL HRA 

RECORDS MGMT

RDRL DCL

TECH LIB

1 GOVT PRINTG OFC

(PDF) A MALHOTRA

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BLDG 5400 RM C242

REDSTONE ARSENAL AL 

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(PDF) SFC PAUL RAY SMITH

CENTER

RDRL HRO COL H BUHL

RDRL HRA I MARTINEZ

RDRL HRR R SOTTILARE

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RDRL HRA B G GOODWIN

RDRL HRA A C METEVIER

RDRL HRA D B PETTIT

12423 RESEARCH PARKWAY

ORLANDO FL 32826

1 USA ARMY G1

(PDF) DAPE HSI B KNAPP

300 ARMY PENTAGON 

RM 2C489

WASHINGTON DC 20310-0300

1 USAF 711 HPW

(PDF) 711 HPW/RH K GEISS

2698 G ST BLDG 190 

WRIGHT PATTERSON AFB OH 

45433-7604

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(PDF) ONR CODE 341 J TANGNEY

875 N RANDOLPH STREET

BLDG 87 

ARLINGTON VA 22203-1986

1 USA NSRDEC

(PDF) RDNS D D TAMILIO

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NATICK MA 01760-2642

1 OSD OUSD ATL

(PDF) HPT&B B PETRO

4800 MARK CENTER DRIVE

SUITE 17E08

ALEXANDRIA VA 22350

1 TARDEC

(PDF) AMSRD TAR R

A JIMENEZ

1 MEDCOM WAMC

(PDF) MCXC WTB CO

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1 THE AMERICAN CENTER FOR

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D HEADLEY

RDRL HRB C

J GRYNOVICKI

RDRL HRB D

C PAULILLO

RDRL HRF

B LANCE

RDRL HRF D

C LENNON

S HILL

A FOOTS

K SCHAEFER-LAY

A MARATHE