If you don't have a car, taxis are the most reliable way to get around Johannesburg, usually. Following the late-night trip back from Potchefstroom I was waiting in the lobby of my colleague's hotel, on the lookout for the taxi that the reception had called to take me to my own accommodation.

As the minutes ticked by, there was no sign of the cab. Not to worry, said the hotel porter. A security guard named Stevie was doing his nightly rounds and he was heading in the right direction and would happily give me a lift. I knew there would be a fee required but the alternative was sleeping in the lobby, so I gladly took him up on the offer.

As he pulled out of the hotel driveway I noticed that something wasn't quite right. The driver's side window had been smashed out and replaced by a plastic sheet, whose most alarming characteristic was that it was not transparent. When you're turning across traffic, it's good to have at least a vague idea of what's coming your way.

Fortunately, we made it onto the main road without incident, although Stevie appeared to be having some trouble staying awake. To his credit, his eyes stayed open at the crucial moments and he was knowledgeable enough to get me to my hotel without needing directions.

But I got the distinct impression that Stevie, the sleepy security guard, would not be overexerting himself on the security side of his job tonight. Not when there's a handy sideline in unofficial taxi-driving to be had. All in all, I hope my next cab turns up on time.