Good news! I didn't crash into the cruiser!

On the way to work this morning, in a steady cold drizzle, I saw flashing blue lights on the bridge not far from my job. I slowed down and saw a state police cruiser, a pickup truck in a diagonal postion on the bridge, and another vehicle after that, all in my lane. The trooper was standing next to some scattered debris, on the other side of the bridge, and I assumed he was directing traffic, since we were now down to a one-lane situation.
At first I thought he was waving me through - he was swinging his arm back and forth, not making the universal the-cop-says-stop gesture with a straight-arm open palm. But then I realized he was swinging his arm with palm outward - an awkward, non-standard, ambiguous gesture. At the last moment, I decided he wasn't waving me through, after all, so put on the brakes.
The brakes didn't catch. I just kept going, at least another car-length. Finally, finally, I came to a stop just a couple of feet behind the parked cruiser's rear bumper. I thought my brakes had failed. I had an adrenaline surge that could have powered up a small city. I gasped with relief when the car stopped moving.
The trooper came walking toward my car. "Don't tell him your brakes failed," I said to myself. "That's a ticket for defective equipment."
I rolled down my window.
"I didn't think you were going to stop," he said.
I stammered something to the effect that I'd been a little concerned, myself, while the voice in the back of my head was saying "Don't mention the brakes. Don't mention the brakes." And I was hoping he'd been too far away to notice the look of terror on my face.
"Everyone else seemed to see my blinking blue light and slow down," he said.
I started to say something about the ambiguity of his gesturing, but then thought "Don't criticize the cop. They don't like that. They write tickets for that."
Now I had two things whirling around in my head that I was trying not to blurt out. Smiling seemed like a good response. Silent smiling, with no talking whatsoever.
"Try to slow it down. It's icy out there," he said.
Icy? It's icy? No wonder I couldn't stop. Not my brakes. Ice. (That also explained why the pickup was diagonal in the road ahead...)
"Yes, sir!" I piped up as he walked away.
He let a couple more cars come through from the other direction, then finally waved me through.
I drove slowly that last little bit to work.