Systems and methods for improved vehicle navigation using mobile communication device (e.g., phone) technology as a means for transmitting vehicle route data that has been updated as a result of changed or changing traffic conditions. A mobile communication device is connected between a vehicle and a remote server. Traffic information from both broadcast and mobile network sources is analyzed by the server, a difference(s) therebetween is detected, and the difference(s) is compared to a predetermined difference value. If the detected difference exceeds the predetermined difference value, difference information is extracted and used to produce updated route data, which is then transmitted via the mobile communication device to the vehicle. The transmission of updated route data is limited to only situations where there is a sufficient change in traffic conditions, and the data transmitted is preferably limited to only difference data so as to avoid exceeding mobile communication device plan limits.