Not sure how often it rains in your area.

So anytime you have not had rain for more than a week and you get a light rain, not enough to really wash down the road you end up with very slippery road surfaces. Sometimes almost like ice conditions.

Also you never know if there was anything spilled on the roadway where you were driving.

One early Saturday this Summer I was driving about 90 minutes to an event. We had had a dry week and it had rained lightly about an hour earlier but it was too early and cloudy for the sun to dry off the roadways. I think in the 90 minutes I saw 8 or more accidents due to the slippery road conditions.

I am guessing that the curving freeway on ramp has a speed limit more in the 30 MPH range. You probably need to adjust your speed and driving habits to the conditions.