Abstract
Keywords
Latest advancements in the Internet of Things (IoT) domain enable real-time transmission of data that can be used to monitor the location, status, and behavior of a vehicle or fleet of vehicles (
The growing availability of such telematics data is transforming the automotive insurance industry. In particular, the information extracted from telematics devices and smartphones allows insurers to provide usage-based insurance (UBI) policies that are based not only on mileage and other contextual driving factors (e.g., time of day or road type), but also on driving behaviors (
Insurance policies that are based on telematics data can be classified into two main categories: those based on pay-as-you-drive (PAYD) models and those based on pay-how-you-drive (PHYD) models. While rates in PAYD are calculated mostly based on mileage, rates in PHYD originate from a multitude of trip-related factors, including measures of vehicle control such as speed and acceleration/deceleration rates. However, implementing usage-based rates can be challenging in certain industries. For example, one of the long-standing challenges in the car rental industry is the inability to differentiate pricing based on a user’s accident history or driving behavior. Rental fees are stratified primarily by factors such as age and gender, which fail to reflect individual risk levels. As a result, some high-risk drivers of private vehicles may shift to long-term rentals to avoid elevated insurance premiums, placing additional burden on rental companies. The possibility for rental companies to align insurance premiums with measures of driver behavior offers many benefits to both insurers, who can provide more accurate pricing, and customers, who can have more control on their premiums and are incentivized to adopt safer driving behaviors (
Ensuring customized insurance policies for corporate vehicles requires the investigation of additional business-related variables that are out of the drivers’ control (
Crash Risk Factors among Commercial Drivers
Drivers who regularly drive a company-owned or -financed vehicle for business purposes are commonly referred to as “commercial” drivers (
Machine Learning Approaches to Predicting Crash Risk
Using machine learning to analyze naturalistic driving data can help inform the risk assessment process in the insurance industry as well as accurately estimate the insurance premium that rental companies could charge to their corporate customers. Existing studies on private vehicles have used a variety of classification methods for collision risk assessment. Among the most common methods, logistic regression (LR) has been used to analyze driving data and assess critical factors related to collisions (
The studies presented above reveal two limitations that offer the opportunity to further investigate collision risk for informing UBI policies. The first limitation is the lack of classification approaches that focus on corporate driving settings, where business-related factors that do not depend directly on drivers’ behavior can affect collision risk. The issue of isolating business-related factors was already acknowledged by Downs et al., but the authors lacked information on how business-related factors were distributed across exposure variables such as mileage and trip frequency (
Methods
We were provided in-kind with a large fleet telematics dataset by our partner organization. The dataset included both
Data
We gained access to the fleet dataset through a collaboration with SK Networks, one of the largest car rental companies in South Korea. SK Networks collected naturalistic driving data as a by-product of equipping their vehicles with an advanced fleet management system (FMS) to optimize operating efficiency and manage emergencies. The FMS devices generating the data consisted of five major parts: 1) an On-Board Diagnostics (OBD) connector, 2) a GPS device that recorded location and speed information every 10 s, 3) a long-range (LoRa) modem, 4) a gravity sensor to monitor speed changes, and 5) a Bluetooth chipset connected with drivers’ smartphones. This was one of the first fleet applications of LoRa technology, which is becoming the leading IoT solution for connecting sensors to an online network and enabling real-time transmission of information across that network. The power of LoRa technologies mainly lies in their capacity, a relative low power consumption, and secure data transmission (
The original dataset included information from 9,412 drivers across 141 businesses completing 5,025,867 trips. A “trip” is defined as the period of driving activity that begins when the vehicle’s engine is turned on (ignition-on) and ends when the engine is turned off (ignition-off). Drivers in our sample drove more than one vehicle during the test period. Thus, we matched all trip data with drivers’ ID by Bluetooth pairing with their smartphone and aggregated the trip data by driver. For example, drivers could have completed 50% of their trips using a compact car, another 25% using a sedan, and another 25% using a recreational vehicle. SK Networks allowed drivers to rent their fleets for personal use at cost price outside working hours. The variable
List of Preliminary Predictor Variables and Summary Statistics
Drivers consented to having their data used for academic research. However, their demographic information (i.e., age and gender) was not released to the authors to ensure privacy protection. SK Networks agreed to share information about the age and licensure of 247 drivers who participated in a survey. These respondents were between the ages of 27 and 60 years (
To remove unreliable GPS data, we excluded trips that 1) lasted less than 10 min, 2) had an average speed of over 150 km/h (highest speed limit in South Korean highways is 110 km/h; usual highway speed limit is 100 km/h), and 3) were less than 1 km or more than 600 km long. Then, we removed drivers whose total mileage was less than 1,000 km, as this threshold is usually considered as a minimum requirement to assess driver behavior and underwrite a UBI contract (
Dependent Variable
Collision involvement was used as a dichotomous dependent variable. Drivers who had experienced any collision in 2018 with a fleet vehicle were assigned a value of 1; otherwise, 0. Most of the collisions involved another vehicle (66.2%), followed by collisions with objects (23.5%) and people (2.0%). In this study, collisions were defined based on SK Networks corporate customer (i.e., businesses) reports that indicated the need of vehicle repair. Damage cost of collisions was used to assess the severity of collisions. The monetary threshold used to differentiate between non-severe and severe collisions was set at 2,000,000 South Korean won (KRW) (∼1,617 USD) based on data reported by the Korea Insurance Development Institute (
Predictor Variables
Predictor variables were selected based on previous research that utilized naturalistic data to identify factors affecting collision risk. For example, elevated gravitational force events (i.e., acceleration and deceleration) were found to have high correlation (r = 0.60) with both crash and near-crash involvement (
The first group of variables related to the drivers’ business and driving environment. Drivers could exercise little control over these variables, as they were mainly dictated by the context of their business. These business/environment variables characterize how much drivers traveled, in what type of vehicle, on what types of road, and during what times of the day. We adopted our time zone and road type categories from Aarts and Van Schagen (
The second group of variables related to driving behavior, including speeding, percentage of uninterrupted driving exceeding 2 h (to capture fatigue), rapid speed changes, and violations of traffic regulations. Under the “Speed” heading (Table 1), the variables
Analysis
We selected the predictors to train our classification models based on whether any of the preliminary variables listed in Table 1 differed significantly (

The correlation matrix of significantly tested explanatory variables.
Although multicollinearity did not pose a problem to the analysis, we decided, for practical reasons, to exclude variables when multicollinearity was present: this way, we avoided considering too many variables in the models, which may be hard to track in real world applications. Variables from the “Travel” category were highly correlated with each other, except for
Finally, given the limited number of observations for each type of violation, we grouped the variables from the “Violation” category into two new variables:
The modeling was conducted in the programming environment R version 3.5.3, using the package
Results
Table 2 reports the performance metrics for each classification algorithm under the four sampling strategies, with the highest value per metric highlighted in bold. The highest AUROC for the algorithms ranged from 0.773 to 0.823, indicating a 77%–82% probability of correct discrimination between collision-free and collision-involved drivers. Concerning trade-offs between precision and recall, the highest AUPRCs for the algorithms ranged from 0.362 to 0.417, with a baseline of 0.133. RF (sampling: none) showed the highest performance for both AUROC (0.823) and AUPRC (0.417).
Performance of Classification Models
High recall may be prioritized over high precision if the objective is to protect against potential losses that the insurance or rental companies would face by giving lower insurance rates to risky drivers who are misclassified as non-risky (i.e., false negatives). This may particularly be the case for rental companies given that they are not privy to historical crash records of individual drivers as insurance companies are, missing an important piece of information to identify risky drivers. Figure 2 illustrates the areas under the ROC and precision-recall curves of the five models that had the highest recall values; all were down-sampled, except for kNN (up-sampled). It can be observed how, at low levels of recall (up to about 15%), down-sampled GBT was the only model holding high levels of precision (75%–100%), indicating that at this cut-off, the rate of false positives was low. However, the five classifiers reached high levels of recall only at low levels of precision, and thus correctly classified many collision-involved drivers only at the cost of misclassifying many collision-free drivers as collision-involved. Confusion matrices for the five models with highest recall are included in the Appendix.

(
Relative Variable Importance and Sensitivity Analysis
We further analyzed the contribution each predictor made to the classification performance. Figure 3 illustrates the contribution of each predictor variable to the performance of the classification models. For the sake of visual clarity in the variable importance graph, we only included the three models with the highest recall. Since kNN does not provide a value for variable importance, we replaced it with the next model with highest recall (i.e., GBT down-sampled). Thus, the three models illustrated in Figure 3 are GBT, LR, and RF (all down-sampled). The variables with highest relative importance belonged to both the

Relative variable importance.
The LR model (down-sampled) was further analyzed by conducting a sensitivity analysis and by observing changes in the probability of collision involvement. Table 3 summarizes the LR outcomes for the down-sampled dataset, showing odds ratios for each predictor and sensitivity analysis based on a 50% increase from mean values. Significant predictors are highlighted in bold. These results were obtained from non-standardized data to aid the reader in the interpretation of odds ratios and the sensitivity values. We increased each of the predictor variables by 50% from their mean values while controlling for other variables to calculate the changes in expected probability. The results of the sensitivity analysis were generally consistent with the effects observed in Figure 3.
Down-Sampled Logistic Regression Results and Sensitivity Analysis
Precision-at-k
In contrast to precision over the entire test sample, precision-at-k analysis assesses precision when the models are used to identify k cases that belong to a particular class (e.g., collision-involved drivers, or collision-free drivers) from the test sample. The five models with the highest precision reported earlier were used for this analysis for both the collision-involved and collision-free classes. Figure 4 compares the precision-at-k metrics for the five models with the highest overall precision scores. Unsurprisingly, precision was generally lower for collision-involved drivers across all models. The two models with highest precision for the collision-involved class were GBT and RF. With k set at less than 5, only GBT held a precision of 100%, but it decreased gradually toward 55% with k set around 50. RF was also the best-performing model for the collision-free class, although all five models held high precision at all levels of k, indicating that 90%–100% of the drivers predicted to be collision-free were actually collision-free. Precision-at-k analysis enables the selection of models that are better at detecting highest-risk drivers and models that are better at detecting lowest-risk drivers; use of multiple models to identify the extremes can then be used to instate penalties or incentives.

Precision-at-k comparison of top five models for (
Discussion
The results of this study are in line with previous naturalistic studies investigating factors related to collision involvement. Running driving time, trip frequency, and rapid speed changes emerged as important factors according to both the relative variable importance and the sensitivity analysis. We also found that critical factors associated with collision involvement related to both drivers’ behavior (e.g., rapid speed changes and safety violations) and business requirements (e.g., running driving time and trip frequency). While business-related variables can inform insurance and fleet rental companies on how to instate insurance and rental rates for their corporate customers, variables that indicate risky driver behaviors can inform both the design of driver feedback systems incorporated to fleet telematics devices and training programs aimed at correcting drivers’ specific hazardous behaviors (
With regard to classification performance, the models in this study showed higher accuracy and AUROC than previous classification studies for collision risk assessment with telematics data. For example, all our five models showed higher accuracy (ranging from 0.86 to 0.87) than the models in Wang et al. (up to 0.83), possibly because of the lower number of drivers in their sample (i.e., 64) (
While all five classifiers achieved relatively high recall, this came at the cost of lower precision: the models correctly identified many collision-involved drivers but also misclassified a substantial number of collision-free drivers (see Appendix). This tradeoff has important implications for real-world use. In PAYD/PHYD insurance schemes, a high rate of false positives may reduce customer trust and lead to unfair premium adjustments. To mitigate these issues, insurers could integrate model predictions with domain-specific rules or enrich the input data with additional contextual variables to better discriminate between high- and low-risk drivers. Ensemble approaches or post-prediction calibration techniques applied in other high-risk domains such as healthcare may also help balance precision and recall more effectively (
The results in this paper suggest that IoT-connected fleet rental companies could become a useful resource of naturalistic driving data for collision risk assessment. Currently, although both insurance and rental companies offer PAYD premiums (e.g., based on mileage), only insurance companies offer PHYD premiums based on telematics data and driver behavior. Generally, fleet rental companies pay the insurance premiums for all their vehicles in advance to insurance companies, and then charge their corporate customers with rental fees that include the average insurance premium costs. In case the crash rate of a fleet rental company exceeds the cost coverage paid in advance, the insurance company increases their premiums. Therefore, the fleet rental company either increases the rental fees in their next contract with their corporate customers or rejects high-risk customers.
The insights from this study can inform the calculation of UBI premiums for different markets and countries. First, this study suggests the possibility for fleet rental companies to also offer PHYD premiums. Although we noted that there could be differences in the data of insurance and rental car companies, we propose that more customized PHYD premiums could originate from cooperative efforts between insurance and rental car companies. The possibility for rental car companies to offer PHYD premiums would allow for better customization of their fees based on their customers’ driving behavior. For drivers with sufficient behavioral data, rental companies could calculate premiums by applying risk multipliers proportional to the predicted collision probabilities generated by statistical or machine learning models, enabling a tiered premium structure reflecting individual risk. For users with limited or no driving history, such as first-time renters, rental companies can implement an initial premium determined by demographic information, coupled with a short-term monitoring period using telematics devices or driving apps. Once sufficient behavioral data is collected during this monitoring phase (e.g., a minimum threshold of driving hours), premiums can be updated to reflect the individual risk profile. In cases where telematics data is unavailable, proxy measures such as driving scores from navigation apps may serve as preliminary indicators.
Second, this study shows that collision risk in corporate driving is not exclusively determined by driving behavior, but also by business-related factors. The calculation of insurance premiums for corporate drivers, in South Korea and worldwide, should consider that some variables related to collision involvement can be outside of drivers’ control. In addition, results from the precision-at-k analysis suggest that our models performed better at identifying drivers with a higher probability of being collision-free, rather than the opposite (i.e., identifying drivers with higher probability of being collision-involved). GBT showed high precision in identifying drivers with high probability of being collision-free, and RF showed high precision in identifying drivers with high probability of belonging in each collision group, which suggests that—at least in this sample—tree-based models might be more reliable than similarity-based models (e.g., kNN and SVM).
Limitations
SK Networks’ privacy protection policy prevented us from including drivers’ demographic data in our analysis. Since collision rates follow different patterns across different age groups and genders, including this kind of information could have offered the opportunity to control for these variables while assessing the impact of others, such as traffic violation records and trip frequency. Additionally, since we lacked specific information on drivers’ education levels, there remains uncertainty about how representative our sample is in this regard. This limitation is acknowledged in interpreting the transferability of our findings. In addition, because the vehicles were corporate-owned and not privately owned by the drivers, behavior may differ from that of private vehicle owners. On the one hand, this may reduce personal investment; on the other hand, drivers could be more cautious because of potential monitoring or reprimand from their employers. This dual possibility is noted as a limitation when considering the transferability of our findings to broader driving populations.
Second, this study considered drivers who were involved in only one collision the same as those who were involved in more than one. The 1 year period considered in this analysis was not considered to be long enough to build models that could further classify drivers who were involved in more than one collision, or who were involved in more-severe collisions. Future studies using samples collected over longer time periods could explore models that predict, for example, individual collision counts or the collision rate per 1,000 km. At the same time, while the proposed models were trained on long-term driving, we have not yet validated their performance on short-term driving data. This is an important area for future work, as accurately classifying high- and low-risk drivers based on limited mileage is critical for UBI applications. Future research will focus on evaluating and adapting the models to ensure applicable risk assessment when only short-term driving data is available. Finally, while our dataset does not include the detailed trajectory or interaction data necessary to compute surrogate safety measures such as time-to-collision, future research could leverage such data to simulate crash risk and complement analyses based on observed collision outcomes (
Conclusions
We conducted a classification analysis with the objective of investigating collision risk factors in a corporate driving sample and informing UBI policies for corporate customers. This paper suggests the possibility for fleet rental companies to offer PHYD premiums based on measures of their customers’ driving behavior, but also noted that variables affecting collision risk are based on both business- and driver-related factors. We found that running driving time, rapid speed changes, and trip frequency had a consistent effect on the probability of collision involvement across the different models built. Our results from the precision-at-k analysis suggest that low-risk drivers can be identified more effectively than high-risk drivers. Insurance and rental companies could use this information to give lower rates to low-risk drivers, while charging the rest of the customers with fixed fees. When analyzing naturalistic data, insurance and rental companies should be mindful of differentiating between factors that are directly under drivers’ control and those that depend on their business requirements. Future studies could investigate the implications of model interpretability in the context of naturalistic data and automotive insurance. In conclusion, the analysis presented here suggests not only a way to reduce high collision rates in corporate driving settings, but also an opportunity for fleet rental companies to charge their corporate customers based on the adoption of safe driving behaviors.
Supplemental Material
sj-docx-1-trr-10.1177_03611981251372464 – Supplemental material for Assessing Risk of Collision with Fleet Telematics for Usage-Based Insurance: Case Study from South Korean Car Rental Operations
Supplemental material, sj-docx-1-trr-10.1177_03611981251372464 for Assessing Risk of Collision with Fleet Telematics for Usage-Based Insurance: Case Study from South Korean Car Rental Operations by Davide Gentile, Birsen Donmez, Dongsoon Min and Trevor Waite in Transportation Research Record
Footnotes
Author Contributions
Declaration of Conflicting Interests
Funding
Supplemental Material
References
Supplementary Material
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