A: OK, I’ve got an up-to-day map. Let’s check the route from here to the airport.

B: Where are we? Oh, here we are. So we drive to the A120 and turn left.

A: No, we turn right. Remember that we are coming from this direction.

B: Oh yes! Sorry! Then we drive to the M11 motorway.

A: How far is that?

B: It’s only seven miles. We turn left to join the motorway and drive south.

A: According to the map, we get off the M11 at the second junction and join the M25. That’s the motorway that goes around the edge of London.

B: That’s another 15 miles, so that’s 22 miles total so far.

A: Then we drive west on the M25. We must be careful to turn in the right direction!

B: Then we drive on the M25. It turns south. When we reach exit 15, we turn left and go west along the M4.

A: Then we take the first Heathrow Airport. What’s the total distance?

B: The journey around the M25 is 33 miles and then 3 extra miles to get to the airport. So how many miles is that together?

A: 22 miles to the M25, 33 miles on the M25, and 3 after that. That’s a total of 58 miles, isn’t it?

B: It shouldn’t take us very long to cover that distance. Remember that we can go quite fast on the motor way.

A: We can only go fast on the motor ways if there isn’t much traffic. I think we should allow ourselves plenty of time to get there. Being early is much better than being late.