Road Not Shown

I have just purchased a new Navman pin 570. I am very pleased with the performance but I am surprised to note that some local road alterations which are in place over two Years are not recognised. It tries to send me down a street that is now one way and the new street which takes the alternate traffic is not shown.

How often are these maps updated?

Maybe you could try the website of the GPS software, they may have downloads available of the latest updates