Before I start to describe my experience, I’d like to say the purpose of this post is to help everyone, including myself, understand the safety features of our beloved Teslas. As such, let’s try not to get distracted by the moral of my driving behavior or other things that are not directly related to the design/behaviors of the car and physics.
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This past weekend was a rainy one probably for many living along the east coast of USA. NYC was no exception. In the early Sunday morning I drove through Brooklyn with my wife. My incident happened when we were on BQE (I278). If you are familiar with NYC highways you'd know how narrow the lanes can be and how bad the road condition is. The part where it happened probably had about 2 foot gap from side of the Model S (a very wide sedan) to the lines on each side. And NO shoulder.
I was traveling maybe 70~75 mph at the moment (not smart) while it was steady raining (not pouring but more than just dripping). And I was shifting from center lane to right lane trying to go around a slow moving car. I remember that was a pretty big SUV. The right lane had a wall next to it without any shoulder. Shortly after I got to the right side of the SUV, I found myself hitting a pot of water (which I couldn't see before I changed lane) and started hydroplaning. It still puzzles what actually happened the next few seconds so here I am seeking help from the crowd wisdom.
(A little background of myself as a driver. I have been driving move than 15 year and have always been an aggressive driver. I have certainly had my shares of hydroplaning in the past. In almost all cases it was easy to recover from it except once a few years ago my hydroplaning in a different car resulted in it spinning and ultimately flipping over. So I'm very familiar with the feeling of hydroplaning. )
As the hydroplaning started happening on Sunday morning, I first felt a shock in my steering wheel probably from the uneven resistance the front tires experienced from the water. Then the car start to slide a little. My first instinct was trying to keep the car going straight through that tight channel between the SUV and the wall to my right. And I did that by slightly steer it in the opposite direction of the sliding. All of a sudden I started to feel strong torque coming from my Model S' steering wheel that's much stronger and sharper than the typical force you'd feel from water. What was even more weird was in the next few seconds the direction of the force kept on changing btwn left and right and did so many times. The whole time I was fighting it and still try to steer the car straight. This must have lasted more than 5 seconds which felt like eternity (my wife later recalled it to be 30 seconds
. During the whole time I was concerned about applying brake could make the situation worse so I kept my speed and eventually slowly passed the SUV as the car regained stability.
Although visually I didn’t see myself hitting either that SUV or the wall, I swear I heard a dull knocking sound from the back during that process. After it was all over, I thought I must have hit something on one side but continued driving as I didn’t otherwise feel the car was damage in a way that would affect its driving. When we got to our destination about ½ hour later, I got out and checked the car and did a walk around. Nothing. No scratch or whatsoever.
As much as I’d like to give myself the credit for a perfect handling of the situation, I honest thought the chance of that is very slim given how narrow the available path was and how fast the car was traveling. As such, I was trying hard to think whether some part of the car’s intelligence helped. My car is a late 2015 version 85D with autopilot. I recently upgraded to version 8.0. So here are a couple of my theories:
1. Basic stability control kicked in and helped straighten the car by braking on each side as it was sliding. Each brake plus my steering probably overdid it and required a counter-reaction from both the machine and me until the tires eventually regained grip of the ground. I think this was the most likely case.
2. I believe the car has side impact detection using its parking sensors (sonnet?) and maybe the radar in the front. If that was properly designed it could potentially increase the precision of the correction it applies to the wheels and the brakes.
What do you think? Anyone had similar experience? Any Tesla engineer here?
****************
This past weekend was a rainy one probably for many living along the east coast of USA. NYC was no exception. In the early Sunday morning I drove through Brooklyn with my wife. My incident happened when we were on BQE (I278). If you are familiar with NYC highways you'd know how narrow the lanes can be and how bad the road condition is. The part where it happened probably had about 2 foot gap from side of the Model S (a very wide sedan) to the lines on each side. And NO shoulder.
I was traveling maybe 70~75 mph at the moment (not smart) while it was steady raining (not pouring but more than just dripping). And I was shifting from center lane to right lane trying to go around a slow moving car. I remember that was a pretty big SUV. The right lane had a wall next to it without any shoulder. Shortly after I got to the right side of the SUV, I found myself hitting a pot of water (which I couldn't see before I changed lane) and started hydroplaning. It still puzzles what actually happened the next few seconds so here I am seeking help from the crowd wisdom.
(A little background of myself as a driver. I have been driving move than 15 year and have always been an aggressive driver. I have certainly had my shares of hydroplaning in the past. In almost all cases it was easy to recover from it except once a few years ago my hydroplaning in a different car resulted in it spinning and ultimately flipping over. So I'm very familiar with the feeling of hydroplaning. )
As the hydroplaning started happening on Sunday morning, I first felt a shock in my steering wheel probably from the uneven resistance the front tires experienced from the water. Then the car start to slide a little. My first instinct was trying to keep the car going straight through that tight channel between the SUV and the wall to my right. And I did that by slightly steer it in the opposite direction of the sliding. All of a sudden I started to feel strong torque coming from my Model S' steering wheel that's much stronger and sharper than the typical force you'd feel from water. What was even more weird was in the next few seconds the direction of the force kept on changing btwn left and right and did so many times. The whole time I was fighting it and still try to steer the car straight. This must have lasted more than 5 seconds which felt like eternity (my wife later recalled it to be 30 seconds
. During the whole time I was concerned about applying brake could make the situation worse so I kept my speed and eventually slowly passed the SUV as the car regained stability. Although visually I didn’t see myself hitting either that SUV or the wall, I swear I heard a dull knocking sound from the back during that process. After it was all over, I thought I must have hit something on one side but continued driving as I didn’t otherwise feel the car was damage in a way that would affect its driving. When we got to our destination about ½ hour later, I got out and checked the car and did a walk around. Nothing. No scratch or whatsoever.
As much as I’d like to give myself the credit for a perfect handling of the situation, I honest thought the chance of that is very slim given how narrow the available path was and how fast the car was traveling. As such, I was trying hard to think whether some part of the car’s intelligence helped. My car is a late 2015 version 85D with autopilot. I recently upgraded to version 8.0. So here are a couple of my theories:
1. Basic stability control kicked in and helped straighten the car by braking on each side as it was sliding. Each brake plus my steering probably overdid it and required a counter-reaction from both the machine and me until the tires eventually regained grip of the ground. I think this was the most likely case.
2. I believe the car has side impact detection using its parking sensors (sonnet?) and maybe the radar in the front. If that was properly designed it could potentially increase the precision of the correction it applies to the wheels and the brakes.
What do you think? Anyone had similar experience? Any Tesla engineer here?
