## 4 Results
### Breakdown of Change in Cost Factors  
Figures 3-6 each provide a breakdown of the change in each cost factor for a 1-ton, 5-ton, 12-ton, and 25-ton truck, respectively, under the current status (i.e., no ATs) and five scenarios. In general, the patterns for the four different types of trucks are quite comparable to one another. The reduction of driver costs, which accounted for around half of TCO for an operational truck in the current logistics business, was the primary factor behind the cost savings that will be realized. Additionally, the new cost component for the remote operation turned out to be the most significant contributor to the overall cost rise across all five scenarios. TCO for ATs increased due to rising acquisition expenses, and the acquisition costs increased the proportion of TCO for ATs.  
In Figure 3, while the monthly wage for a driver of a 1-ton HDT was USD 2430, the driver cost was eliminated in all five scenarios. The acquisition cost of a 1-ton HDT was USD 611 per month, and the cost increased by USD 153 in scenario 1 (the most pessimistic scenario) and USD 61 in scenario 2 (the pessimistic scenario). Scenario 5 (the most optimistic scenario) results in a monthly TCO saving of USD 53 due to lower fuel consumption.  
Figure 3: Breakdown of the cost structures for a 1-ton truck under the current status (i.e., no ATs) and five scenarios in the case study of the route (unit: USD per month).  
Figure 2: Percent change in the total cost of operation for autonomous trucks under the five scenarios (unit: percent).  
The findings of Figure 4 reveal that the cost of a 5-ton AT will be reduced by USD 2835 per month, while the cost for remote operations of ATs will increase by USD 1134, USD 567, USD 284, USD 198, and USD 142 per month for scenario 1, 2, 3, 4, and 5, respectively. The costs for regular checks and maintenance showed a significant reduction, which amounted to USD 277 per month in scenario 5.  
Figure 4: Breakdown of the cost structures for a 5-ton truck under the current status (i.e., no ATs) and five scenarios in the case study of the route (unit: USD per month).  
Figure 5: Breakdown of the cost structures for a 12-ton truck under the current status (i.e., no ATs) and five scenarios in the case study of the route (unit: USD per month).  
Figure 6: Breakdown of the cost structures for a 25-ton truck under the current status (i.e., no ATs) and five scenarios in the case study of the route (unit: USD per month).  
Figure 5 shows that the driver cost of a 12-ton HDT was USD 3240 per month, which was equivalent to around 40.6% of TCO for a 12-ton truck. However, ATs will be able to eliminate this cost and offer considerable operation cost saving for freight transport operators. However, remote operations and acquisition costs significantly increased, by USD 1296 per month in total in scenario 1 (the most pessimistic scenario).  
In Figure 6, a 25-ton AT will save USD 3645 per month due to the presence of a driver on an HDT. The acquisition cost increased by USD 382 and USD 153 per month in scenarios 1 and 2, respectively. The environmental improvement fee, which accounted for 10.6% of TCO, was an important cost element for a 25-ton truck. Since driving automation will be able to improve pollution emissions [27], the cost factor may be an additional significant cost component that will offer TCO savings for freight transport operators. However, this economic factor was not considered in this study because previous literature has not provided a clear indication of how much of a cost reduction there would be in terms of the improvement fee for the environment.