What are the measures to deal with the accumulated water in railways and overpasses?

For pedestrians, the water in railways and overpasses is to avoid wading risks, and the sections with unknown water depth should be bypassed; For motor vehicles, the countermeasures are: to know the safety and limit wading depth of the vehicle, wading slowly, recovering the braking performance after wading, not following the car and not starting again.

1. Understand vehicle safety and limit the wading depth.

Every car has a safe wading depth and a limit wading depth. The safe wading depth is less than the height of the exhaust pipe, which is generally half of the hub. The water level at this height can be easily passed.

The limit wading depth is close to the automobile air inlet, but it cannot exceed the air inlet. This requires everyone to know the air intake of their car in case of emergency. Air intakes are generally located at the two sides or front end of the engine compartment, and can be found along the thick air intake pipe and air cleaner box.

If the water depth is between the safe and the limit wading depth, then the driver needs to pass carefully, use low gear, pass slowly and keep the throttle steady. And be sure to wait for the front car to pass through the stagnant water before letting the rear car pass. Observing the driving trajectory of the preceding vehicle can avoid accidents and increase the difficulty of operation, and avoid the water level rising caused by the mutual interference between the two vehicles.

Step 2 wade slowly

Generally speaking, it is best not to drive more than 20 km/h on the road with accumulated water. Be sure to shift to a low gear, keep the speed above 3000 rpm, and control the steering wheel to avoid being affected by the current.

Automatic transmission models can shift to manual 1 or L gear, because people are used to driving in D gear, but D gear will automatically shift according to the vehicle speed and speed, and the automatic upshift speed will inevitably decrease when driving in water, so that the pressure in the exhaust pipe will suddenly decrease, resulting in back pressure, which will lead to water being sucked into the exhaust pipe, leading to poor exhaust and flameout.

Of course, such flameout will not damage the engine. As long as the water in the exhaust pipe is drained and the exhaust is smooth, the vehicle can be restarted. But it's best to check the three-way catalytic converter after the event, because it is likely to be damaged by blisters.

3. Restore braking performance after wading

When the car is wading, the surface of the brake pad will be slippery. When the brakes are used after wading, there is often a phenomenon of "can't stop", which leads to traffic accidents.

In order to avoid this short-term brake failure, you should lightly step on the brake pedal after wading, let the car grind while walking, and then accelerate until it is about to stop. It is advisable to step for 8 to 10 second each time, and repeat for five or six times. If the braking distance is still very long, you need to brake several times before driving a certain distance, and then check it again until the braking performance is fully restored before accelerating.

4. Don't follow the car.

When you encounter a wading road, you must first observe it. Because the water is dirty and turbid, you often don't know the depth of the water, especially on some bumpy roads. Don't drive in front of the car at this time. If the front car displaces some water, the backflow of water will splash a lot. If we follow up at this time, the wading depth will be greatly increased. In addition, it can also prevent the front car from stopping due to fault, forcing the rear car to stop in the water, causing two piles of advance and retreat.

5. Don't start wading again.

Because the engine speed is low when the vehicle passes through the accumulated water, water enters the exhaust pipe, which makes the engine exhaust poorly and causes flameout. Don't try to ignite again at this time. Call a tow truck for rescue as soon as possible. Because water is likely to enter the engine cylinder at this time, once the engine is forced to run, it will cause more serious failures.