Figure 38: AIPV system layout [97

Figure 38: AIPV system layout [97]

The first AIPV program in the USA was launched by the Colorado DOT in 2017 [98]. The positive experience led to an autonomous maintenance technology pool fund including 12 paid state DOT members [99]. The Pool Fund currently has 14 State DOT members, including Alabama, California, Colorado, Illinois, Indiana, Kansas, Minnesota, Nevada, North Dakota, Ohio, Oklahoma, Texas, Virginia, and Washington DOTs. The Missouri DOT awarded a contract to purchase two AIPV vehicles for work zone maintenance in 2018 [87]. The following year, the University of Tennessee Center for Transportation Research announced an AIPV pilot demonstration. In Florida, the University of Florida in collaboration with the Florida DOT is also initiating plans to evaluate AIPV [95]. Aside from these states, California. Minnesota and North Dakota have purchased AIPV systems and vehicles indicating that the interest for this technology is increasing fast among the country’s DOTs. The details of the initial experience of these states and research institutions with AIPV will be discussed later.

3.3.1.1 Advantages and Disadvantages

As mentioned before, the main benefit of the AIPV system is removing the driver from harm’s way, which includes potential death or lifelong injury. According to a 2021 study, developers also point out other advantages of the AIPV [96]:

58

• Removing psychological trauma: there is a psychological impact upon the driver since the worker is considered to be a “sitting duck” waiting to be hit. In addition, the fear of potential catastrophe also affects the worker’s family and community of support. • Repurposing of worker: with an autonomous process, the IPV truck driver can operate another vehicle in safer conditions or even be trained to monitor the autonomous vehicle’s operation from the leader truck. Since this worker has experience with moving working zones and IPV, they can effectively assess the performance of the AIPV. • Removing human error: automated vehicles maintain the designed gap distance with great accuracy; human drivers will often, unconsciously, vary the gap distance coming too close to their protected vehicle or work zone endangering them with a secondary impact. In addition, safety and trust can be improved because the AIPV will remain on track even in extremely dangerous situations. The human basic instinct for selfpreservation is removed with the driver. Moreover, the AIPV will automatically brake the vehicle upon impact, an action that sometimes is overlooked by human drivers. • Removing financial hazards: Using a AIPV eliminates insurance claims of lifelong injury, including huge medical expenses and worker compensation payments in cases of accidents mitigating liability. In addition, considering the 2016 US Department of

Transportation “economical value of a statistical life” of 9.6 million dollars, if the AIPV system avoids a single death, the investment will be a huge financial success.

From the perspective of workers, the pool fund study developed an initial research into the perception and acceptance of AIPV by work zone workers. The study surveyed 13 workers from the Colorado and California DOTs on their experiment with AIPV. In total, 13 DOT workers responded to the survey. Based on worker level of AIPV experience, they were classified as High and Low experience. Results showed that, overall, workers have a positive acceptance of the AIPV technology indicating that it was a safety improvement, as compared to having a human driving the IPV. High experienced AIPV workers reported significant greater trust in AIPV when compared to less experienced workers suggesting that trust and acceptance increase with experience and proper training [95].

59

Nevertheless, workers expressed concerns regarding reduction in crash frequency and project duration. Some workers also have doubts concerning the AIPV ability to safely change lanes and maneuver in horizontal and vertical curves as well as operation during several adverse conditions like poor visibility, adverse weather, and denser traffic volumes [95]

AIPV are suited for fast-track technology development programs which are common in many US states due its deployment being based on highly controlled mobile work zone environments. State DOTs are encouraged to test the technology in a closed and controlled environment before real life situation environments [96]. Testing can be conducted following the criteria developed by a 2021 study in which the AIPV system’s performance is evaluated as follows [86]:

• Statistical indicators: For each test, the overall statistical indicators are selected and tested to assure that the system meets basic requirements of operation. • Probability Distribution: For each test, an analysis was made do disclose the probabilities of errors within a certain range. • Consistency: The performance must remain the same for different scenarios

Several tests based on different scenarios were conducted to evaluate the performance of an AIPV [96]. Results are in Table 5. Tests that achieved successful results are highlighted in green. Tests that were not consistent in achieving adequate results are in yellow. Failed tests are highlighted in red.

60