Every few years, the DC region suffers an epic transportation failure when a small storm puts down a light coating of ice or snow on roads -- and catches the local governments of two states and the nation's capitol by surprise. That's what happened Wednesday night.

You may be wondering why this occurs, given the amount of technology dedicated to watching weather patterns. The answer is simple: Humans, not machines, were at fault.

Computer models accurately predicted Wednesday night's snowfall. But forecasters focused way too much on this weekend's blizzard. Word about Wednesday's storm didn't get out from the media. And the region's governments didn't put out enough salt trucks.

Without chemicals, cars could not get off the highways because many exit ramps slope upward and were too slick even for SUVs with four-wheel drive. The crashes that littered icy neighborhood streets could not be cleared quickly because crews were initially focused on the Interstates. Roads backed up everywhere. Drivers were stranded for as long as six hours in their cars.

Here's a glimpse of what roads around D.C. were like at 8:30 pm Wednesday night. There was no way to get anywhere.

I made it as far as downtown McLean. And then, because car crashes were blocking every road to my home, I had to abandon my car in a church parking lot and walk the last mile.

It was a beautiful stroll through dark, snow-covered paths. My iPhone battery had died, likely drained by my overuse of Google Maps during my four hour drive home (usually it takes less than 25 minutes).

With no smartphone and no car, I had not a single bit of working tech on me -- a small consequence of what happens when humans at the switch fail to heed the warnings technology delivers to us.