‘Attention!’ the voice intruded. ‘Your route has been changed.’

I was driving south along the A1 expressway in the UK, driving from my birthplace, Boston in the East Midlands, to Heathrow to the west of London – to catch my flight home to Kenya. (Editor, this time please note that I am talking about Boston in the UK, the original Boston of medieval fame and not the upstart one in the US!)

It was Friday 20 July, and it was raining like it rarely rains in Europe – a heavy and persistent monsoon rain like we get here in the tropics. But I was comfortable on the expressway, maintaining a steady speed and trusting other drivers to keep their distances.

Also, I was enjoying the Sat-Nav on my hire car. It was the first time I had used the system and I had been both impressed and intrigued as I had driven around the English countryside.

This is how it works…. You press the Nav button on the dashboard and enter your destination in the display. Like on that Friday, I had entered’ Raddison Hotel, Heathrow’ – where I was intending to meet a friend for a long lunch chat before returning the hire car at the airport.

A voice says ‘Calculating route.’ It was a woman’s voice – but flat, almost robotic. But she was my driving companion for a couple of weeks, so I got quite used to her. I certainly got to trust her.

On that last day, she came up with three possible routes. I chose the quickest and the most familiar: a winding county road to the A1, turning off to the M25 and finally the M4 motorways. Easy, it should have been; and the stated ETA – estimated time of arrival – was nicely 30 minutes before my lunch date.

What happens is that to the left of the steering wheel there is a map showing your progress along the chosen route – a map whose scale you can adjust. In front of the wheel is a display in which a broad red arrow indicates what you should be doing – going straight on, turning left or right, taking an exit from a roundabout. It also shows the distance travelled, the distance to your destination, the ETA, and evn the distance before you will next hear ‘the voice’.

But it is the voice that really does the business. ‘Proceed along this road for 15 miles,’ she says. ‘Prepare to approach a roundabout.’ ‘Take the second exit onto the A16.’ ‘In 200 yards bear slightly left.’

The precision is amazing. When I pulled over to a small supermarket to for a ‘relief stop’, she warned, ‘You are off route – Recalculating route.’ But when I stopped at a petrol station that she recognised, the display neatly showed the three sides of a small square I would be doing to negotiate the station forecourt. I am told that the precision is because you are being tracked by at least three satellites.

Sometimes, though, the system notices many stopped cars and decides to intervene. Like on the Friday, the day of the big floods in England.

‘Attention!’ the voice said. ‘Your route has been changed.’ And she took me off the motorways and into territories where I had never been before – through the outskirts of London and along backstreets of Wembley, Acton and Ealing.

Again and again she changed my route. ‘To avoid traffic congestion,’ she kindly explained.

Eventually I arrived at the Raddison Hotel, Heathrow – three hours after the original ETA. It was only later that I realised that the Sat-Nav had saved me from certainly a missed flight and, perhaps, a cold night marooned in my car. Because, left to my own devices, I would have stuck to the motorways and driven up to the deeply flooded M25 and into some of the worst traffic jams England has known for many years.

Now, back home, I’m wondering how Sat-Nav, when it comes to Kenya, will cope with the Nairobi traffic. How many times a day will the robotic voice have to say, ‘Attention! Your route has been changed because of traffic congestion’? Will it ever find a route through?

And how will it manage the up-country hazards? How will it respond to the mud-holes, the flash-floods and the herds of cows?

Published in Kenya’s Sunday Nation