###### Abstract  
The general approach in the previous studies was to ignore the driver's steering contribution to a vehicle while investigating the interactions between crosswind and vehicle. Therefore, the goal of this study is to find out how steering inputs by drivers affect a heavy-ground vehicle's dynamic reaction to crosswinds. In the investigation, a two-way interaction between vehicle dynamics and aerodynamic simulations was employed. The steering inputs of drivers were modelled using a driver model taken from the previous literature that is able to reproduce the steering responses of a human driver. The study's findings demonstrated that the steering inputs made by drivers significantly impacted how the vehicle responded to crosswinds. For instance, the greatest lateral displacement of the least skilled driver (Driver 1) was around 1.53 times the greatest lateral displacement of the most skilled driver (Driver 3) at the delay time of \(t_{\delta,delay}=0.5\) s in the steering input. Additionally, the maximum lateral displacement results of Driver 1 and Driver 3 at \(t_{\delta,delay}=1.0\) s became 1.39 and 1.56 times greater than their maximum lateral displacement results at \(t_{\delta,delay}=0.5\) s. Similarly, the total steering inputs of Driver 1 and Driver 3 at \(t_{\delta,delay}=1.0\) s were 1.4 and 2.2 times greater than their total steering inputs at \(t_{\delta,delay}=0.5\) s, respectively. In general, the results of a driver who is more skilled than Driver 1 (Driver 2) fall in between the respective results of Driver 1 and Driver 3. On the other hand, each driver's total steering inputs at \(t_{\delta,delay}=0.5\) s were roughly the same as their total steering inputs at \(t_{\delta,delay}=0\) s. In all delay scenarios for the start of the driver's steering inputs, the drivers' steering inputs amplified the yaw moment applied to the vehicle. Meanwhile, they diminished the lateral force and roll moment. coupled simulation; crosswind; driver model; driver behaviour; heavy-ground vehicle +
Footnote †: journal: Applied  
0000-0002-2300-3000]L.A.  
and the comparatively elevated positioning of the centre of gravity in contrast to passenger cars [3]. [PERSON] et al. [4] asserted that safety-critical situations in heavy ground vehicle accidents, such as loss of control leading to roll-overs and compromised lateral stability, represent a significant portion of all reported incidents involving heavy vehicles. [PERSON] and [PERSON] [5] investigated the directional stability of buses subjected to crosswinds. They determined that the key factors include the extent of the yaw moment overshoot upon entering a gust and the inherent characteristics of a bus, such as weight distribution, coupled with the position of the aerodynamic pressure centre. Consistent with the aforementioned studies, the current investigation focused on examining the dynamic characteristics of heavy-ground vehicles when they are subjected to crosswinds. When a crosswind hits a vehicle, a complex interaction between the crosswind, vehicle, driver, and on-road conditions occurs, in which the characteristics of each can have important effects. For example, the frequency or maximum velocity magnitude of crosswinds, types of vehicles, driver's skills, and floating bridges or winter roads can exert a significant impact on the response of a vehicle to crosswinds. Inherently, a multidisciplinary approach is required to comprehensively understand the effects of each characteristic. Thus, the number of studies aimed at elucidating the knowledge of the effects of crosswinds on vehicles has increased in recent years [6; 7; 8; 9; 10; 11; 12; 13; 14; 15]. For instance, [PERSON] [6] investigated the effects of various crosswind frequencies. Additionally, [PERSON] et al.