It couldn't have happened at a worse time. It was day three of a four day, eight presentation road trip with one day to go. I had wrapped up a wonderful morning keynote at the Growing Rural Tourism conference in Camrose, Alberta to an enthusiastic audience, flown back to Kelowna and was now driving to my next destination.

The plan was to make the two and a half hour drive, check into my hotel and get about six hours snooze time before getting ready to deliver two half day presentations.

About thirty minutes into the drive on a very windy mountain highway I started to hear a light knocking noise and feel a slight tapping coming from the front of the car. After a quick inspection I concluded it must be a flap on the front bra that covers the hood. By an hour later the shaking had gotten so bad I decided to turn around (I'd now been driving for 90 minutes), head home, switch cars and head out again. It was going to be one very long night, but at least it would be safer than continuing.

On the return trip the shaking continued to get worse to the point where I was becoming convinced that this was a serious engine breakdown. About an hour later and now some forty five minutes from home I had to pull over. The shaking was terrible and the car felt very unsafe. As I got out of the car a thought came to mind.

The last servicing done on the car was just before I flew out of town. I had the summer tires put on. "It's got to be about the wheels!" was the thought I had as I knelt down by the front left wheel. And that's when I saw it.

Actually that's when I didn't see them - the wheel lugs that is. The five lugs that hold the wheel on had become two and even they were only finger tight. The wheel had be spewing wheel lugs and getting progressively looser as I drove. Twenty minutes more and I would have surely been doing the demolition car derby across highway 33.

So how does this happen? The owner of the shop explained "We do have procedures. But," he added "we are dealing with humans." A bit lame, but I understand. Stuff comes up: the phone rings, someone calls you over for advice, a customer walks in, whatever. But these are wheels on vehicles that are travelling at high speed full of live bodies that want to get to their destination in the form they started in.

Pilots have check lists, surgeons have multiple sets of eyes watching their work and first aid attendants rely on practiced acronyms (think ABC: Air, Breathing, Circulation) to help them in stressful situations. These safeguards are there to cover for the inevitable lapse in human attention.

My father in law tells the story of reluctantly agreeing to fly with a fellow doctor who had recently received his pilot's license. Just before take off the single engine on the plane suddenly stopped. "Damn!" exclaimed the rookie pilot "I forgot to turn the fuel on." What if there had been enough fuel in the lines for ten more minutes? (I don't think he'd be saying 'Damn' then).

We're not all doing open heart surgery, but we all have responsibilities. What is your one last check? Surely that tire shop could have a check list the worker has to check off, or a second person does a quick inspection. Just as it doesn't take much to be distracted it doesn't take much to catch and correct a mistake.

"This is our worst nightmare." the shop owner told me. Great, now do something about it.