Road map displaying system for automotive vehicle

A road map displaying system for an automotive vehicle for displaying road information transmitted by fixed transmitters on a display unit of an automotive vehicle, which comprises:

• (a) means for receiving road information including position data and traffic snarl data transmitted by the fixed transmitters;
• (b) means for storing a plurality of road maps;
• (c) means for selecting a current road map from those stored in said storing means on the basis of the received position data;
• (d) means for displaying traffic snarl information on the selected road map on the basis of the received traffic snarl data;
• (e) means for measuring time elapsed after the road information from the fixed transmitter has been received by said receiving means;
• and
• (f) means for deleting the traffic snarl information displayed on the selected road map, when a predetermined distance-related condition is satisfied after the road information has been received;
• wherein the predetermined distance-related condition is a predetermined vehicle travel distance.

A method of displaying road information transmitted by fixed transmitters on a display unit for an automotive vehicle, which comprises the steps of:

• (a) checking whether road information including position data and traffic snarl data is received from a fixed transmitter;
• (b) if received, storing the received road information;
• (c) displaying a road map on the display unit on the basis of the received position data;
• (d) displaying traffic snarl information on the displayed road map on the basis of the received traffic snarl data;
• (e) if road information is not received a predetermined time period, calculating vehicle positions by a vehicle position detecting unit to display a new road map on the display unit;
• (f) checking whether a predetermined time-related condition is satisfied after the last road information has been received;
• (g) if not satisfied, keeping the last traffic snarl information displayed on the road map;
• and
• (h) if satisfied, deleting the last traffic snarl information from the road map.

A method of displaying road information transmitted by fixed transmitters on a display unit for an automotive vehicle, which comprises the steps of:

• (a) checking whether road information including position data and traffic snarl data is received from a fixed transmitter;
• (b) if received, storing the received road information;
• (c) displaying a road map on the display unit on the basis of the received position data;
• (d) displaying traffic snarl information on the displayed road map on the basis of the received traffic snarl data;
• (e) if road information is not received during a predetermined time period, calculating vehicle positions by a vehicle position detecting unit to display a new road map on the display unit;
• (f) checking whether a predetermined distance-related condition is satisfied after the last road information has been received;
• (g) if not satisfied, keeping the last traffic snarl information displayed on the road map;
• and
• (h) if satisfied, deleting the last traffic snarl information from the road map.