Satellite navigation systems

Alice: Hello, I’m Alice.
Stephen: And I’m Stephen.
Alice: And this is 6 Minute English! This week we’re talking about sat navs.
Stephen: Sat navs – that’s short for satellite navigation systems.
Alice: They’re the gadgets people put in their cars to help give them directions. Engineers have been asking if we’re becoming too reliant on them. Before we find out more, here’s a question for you, Stephen:
Stephen: Ok – I’m ready and waiting.
Alice: When we talk about ‘satellite navigation’ in English, there is an abbreviation we use called GPS. Do you know what it stands for? I’ll give you some choices. Is it:
A) greater place signal
B) global positioning signal, or
C) global positioning system
Stephen: I’m pretty sure I know the answer – but I won’t spoil it for everyone else. I’ll tell you at the end of the programme.
Alice: That’s fine. Sat navs using GPS have become very popular in recent years. But they can sometimes get people into trouble. The BBC News website has lots of examples about people driving into rivers or getting stuck on roads which are too narrow. This woman is talking about the lorries which keep getting stuck under a 15th century stone archway in her town because they’re following directions on their sat navs.
Insert 1: Woman
The amount of lorries that we see nearly every day – they get to that point and there’s no signs anywhere. At the bottom of the road, it doesn’t say: “Don’t go down there – there’s a bridge.” And they get to this point here and every one of them have to reverse – and there’s cars everywhere. It’s just absolute mayhem.
Alice: Oh dear – she says it’s mayhem. Lorries either get stuck under the bridge or they cause lots of problems trying to turn around –

or to go backwards, to reverse – on a very narrow road. She says it’s absolute mayhem.
Stephen: Mayhem – chaos.
Alice: In another incident, a car got stuck on the edge of a steep hill when its sat nav directed it down a path which wasn’t suitable for vehicles any more. Antony Chmarny, who works for a satellite navigation manufacturer, says the gadgets should only be used as an aid to driving:
Insert 2:
Sat nav voice: Turn around when possible – then turn right.
Antony Chmarny: If it doesn’t look suitable, don’t drive down it, don’t drive down a one-way street the wrong way if a sat nav tells you to do that.
Alice: I think he means, use your common sense – don’t drive down a one-way street the wrong way even if a sat nav tells you to do it!
Stephen: I like the sat navs which you can programme with different voices – so you can have your favourite singer or actor with you in the car as your navigator!
Alice: What a good idea! Let’s hear now from an engineer who is worried that we’re becoming too reliant on sat nav and GPS technology. Professor Martyn Thomas from the Royal Academy of Engineering says the weak radio signal it uses can easily be messed up.
Stephen: Messed up – that’s interfered with, or destroyed.
Insert 3:
Professor Martyn Thomas: You can get interference – either deliberate or accidental interference, because it is a very weak radio signal. BBC interviewer Justin Webb: Yes, it’s quite easy, isn’t it, to mess it up?
Professor Martyn Thomas: Oh, extremely, yes. The radio signal is about the strength… in light terms, it’s like looking at a 100 watt bulb from 12,000 miles away.
Justin Webb: So someone who really wanted to put out a large area – satellite navigation systems, could do so?