In the 90s on the business trip, I was caught in one of those I-10 floodings....traffic just stopped, and the water kept rising. I could see water flowing down the on and off ramps, the levees having overflowed.... I drove my rental Caprice up the side up the embankment to the access road above. Not straight up, but at an angle and I went slow but didnt stop.... There were thousands of cars under water that day...and people seemed frozen in what to do.
Might've been a flood in '92 (not the Oct '93 one) or ... who knows. I just remember needing to be at Westheimer and West Loop at a restaurant for a meeting about 4PM and it was impossible to get there.
But most places in Houston, except near Sims or way up NE, if you wait 30 minutes, it will all be gone. Most of the time!