Navigation device and method for early instruction output

A method, comprising:

• determining, during travel of a navigation device along a travel route, when a GPS signal is received by a navigation device and determining when a GPS signal was not received by the navigation device for a period of time exceeding a threshold;
• and
• outputting a navigation instruction to a user of the navigation device, for travel along the route, upon determining that a GPS signal was not received by the navigation device for a period of time exceeding the threshold.

A navigation device, comprising:

• a processor to determine, during a route of travel of a navigation device, entry of the navigation device into a tunnel;
• and
• an output device to output a navigation instruction to a user of the navigation device within the tunnel, for travel along the travel route, upon the processor determining, subsequent to determining entry of the navigation device into the tunnel, at least one of the tunnel being longer than a first threshold distance, a navigation instruction being due to be output within a second threshold distance of an exit of the tunnel and the navigation instruction being due to be output within the tunnel.

A navigation device, comprising:

• a processor to determine, during travel of a navigation device along a travel route, when a GPS signal is received by a navigation device and to determine when a GPS signal was not received by the navigation device for a period of time exceeding a threshold;
• and
• an output device to output a navigation instruction to a user of the navigation device, for travel along the route, upon the processor determining that a GPS signal was not received by the navigation device for a period of time exceeding the threshold.