Living in LA, it feels natural that the summer sun is strong and that there is no rain for months on end.

However, when the seemingly endless summer passes and it suddenly starts to rain, the number of traffic accidents in the city reportedly spikes.

The reason for the increase in traffic accidents on rainy days in LA is due to the slippery roads created by this "first rain."

LA has a dry season for more than half of the year, allowing various pollutants to accumulate on the roads for a long time.

Rubber dust from car tires, metal dust from brake pads, oil residues like engine oil or coolant, and dust and exhaust from the air stick to the road surface.

On sunny days, these substances adhere to the asphalt like a thin film. They may not be visible, but the surface has already become greasy.

When the first rain arrives after months, it creates a fine layer of oil on top.

Particularly in LA, due to the city's structure, there are many areas where water tends to pool when it rains. In places like old road surfaces, low hills, and intersections, water accumulates, making the oil film thicker.

Drivers may apply the brakes as usual, but the car can slide, or they may experience the rear wheels slipping while turning. The tire grip drops sharply. This phenomenon is most dangerous during the first 15 minutes after it starts to rain.

After a while, when the rain pours down heavily, the oil and dust are washed away, making the roads somewhat safer.

Another reason lies in LA's driving culture itself. The weather is so nice that most people are not accustomed to driving in the rain. When it suddenly rains, visibility decreases and brake response changes, but the body does not remember that.

As a result, many drivers maintain their speed or do not reduce their following distance, leading to accidents. Moreover, LA's wide roads and long straight sections can create a false sense of security, making it easy to think, "This should be fine," but that is the most dangerous thought during the first rain.

When it rains, if you look closely at the road, the white paint on the lane markings shines particularly brightly. The reason this area is especially slippery is that the fine plastic components in the paint lose almost all friction when they come into contact with water.

Similarly, metal drainage grates, manhole covers, and iron covers on the road are also very slippery. Therefore, it is important to maintain your driving line to avoid stepping on lane markings and to avoid sudden acceleration or hard braking when the first rain falls. In fact, in the city of LA, the number of traffic accidents on the day of the first rain increases by two to three times compared to usual.

Ultimately, the reason the roads are slippery on rainy days in LA is not just because of the rain, but because of the "dust and oil accumulated during the long dry season" melting away all at once.

 The first rain in LA is romantic, but it also signals the hidden dangers the city holds. Until the roads are cleaned as the sky is washed away, it is wise to drive cautiously during that time.