Prevent submerged vehicle crashes
Of course, the best solution to prevent casualties of submerged vehicle crashes is to make it impossible for vehicles to end up in the water. Firstly, by not planning roads along waterways. If there is no alternative, the distance between the road and the water should be maximised. In this, the obstacle-free zone recommended by CROW could serve as a guideline.
In addition, a well-positioned barrier may help prevent submerged vehicle crashes. A Swedish 2008 study showed that in 46% of submerged vehicle crashes no barrier was present. In 23% of them, the barrier was not correctly positioned, and/or inadvertently functioned as a ramp because of an inadequate layout. The barrier ends often sloped to the ground, which guided or catapulted cars to the wrong side of the guard rail.
Finally, all measures that prevent submerged vehicle crashes may help, such as road signs and (profiled) road marking, rumble strips and a load-bearing roadside [2] [10] [11]. In-vehicle systems such as Lane Departure Warning (LDW)or Lane Keeping (LKS) may prevent a vehicle going off the road. For more information, see SWOV fact sheet Intelligent transport and advanced driver assistance systems (ITS and ADAS).
Ensuring a speedy exit from submerged vehicles
To increase chances of survival, vehicle occupants should exit their submerged vehicles as soon as possible. The preferred method is by rolling down the window (if possible) or breaking the window with an emergency hammer [12]. and exiting that way. These actions should be carried out without delay. A vehicle sinks in three phases: floating, sinking and submersion. The vehicle will remain afloat until the water outside the car reaches the bottom of the windows, and during this phase it is virtually impossible to open the door because of the external water pressure. During the floating phase, an escape through the window increases the chance of survival. As soon as the water is above the bottom of the windows and the water level outside is higher than inside, the vehicle will start to sink. By breaking the window in this phase, the glass will wash into the vehicle, which may cause serious injuries. In the final phase, the vehicle is completely under water and submerged, which minimises chances of survival [12].
