Years ago I was going northbound on 45S in afternoon rush hour. Ended up in the far left lane right behind an old blue van with a ladder on top. We're cruising along and hit an overpass or some bumps or something and that's when I realized the ladder isn't tied down. The ladder pivots exactly 90 degrees such that half of it is over the van and the other half is extending out in free space and may have been in the next lane over. The ladder sits there perfectly balanced on the rack on tp of the van, waving gently with road. I freaked out, cars start evacuating the are around the van. Ladder stayed perched on top of the van long enough for me to get by him. Last I saw he must have realized the ladder was loose as he was signaling and moving over. Of course, maybe that was just his exit and he was clueless.
More recently while driving East on the South Beltway, I passed two cars parked on the shoulder on top of an overpass, somewhere around Mykawa or another closeby road. I notice the front car has it's hood up and there is a guy in the engine bay, another guy looking under the car, and a woman standing between the cars / guardrails. As I pass by them, I hear what I can only compare to a gunshot. I start scanning and carch sight of an airborne debris cloud. An F150 had drifted onto the shoulder and rammed the cars at near full speed. I saw at least one person bailing over the guard rail and down the overpass, but I was sure I had just seen someone die. Never even saw anything about it on the news.
Caught a red eye into IAH one night and get in my truck to drive home. Get on Beltway West headed South and can clearly see thick black smoke rising up in the sky. Keep driving and eventually realize I'm going to pass right by this. Come up to 90 and realize the fire is right next to the Beltway. There are 2-3 cop cars on the overpass, cops are looking at the fire from the guardrail, and I can see flames shooting up past the height of the guardrail. Checked and that one made the news. Gasoline tanker was on the surface street turning left, somehow rolled the rig in the turn, gas leaked, lit off, and burned everything up. Luckily, some passerby pulled the driver out of the truck so he lived!
Those are my top 3. Not nearly as crazy most of the others on here. Except that ladder, I can still pull a vacuum on my chair just thinking about that thing spinning around while I was 6' behind that van.