Personal navigation devices (PNDs) provide geolocation, maps, turn-by-turn directions, and, in some newer models, real-time traffic and weather updates. PNDs make up one of the largest consumer markets for GPS enabled devices. Currently there are an estimated 114 million PNDs in use worldwide, but that number is expected to remain relatively flat over the next few years while turn-by-turn navigation systems on smartphones are expected to increase and overtake sales of PNDs by 2013.
All PNDs work essentially the same way. They store map data locally on the device, which must be updated with some frequency (quarterly or annually). In some cases, additional map data must be purchased and loaded for areas outside of the default geography loaded on the device. Some newer PNDs provide some real-time weather and traffic data via a data connection over a cellular network. The TomTom Live service, for example, runs on AT&T’s wireless network and provides a range of services including a TomTom Buddies service that is similar to the friend finder services in smartphones, described above.
Smartphone based personal navigation applications can work in one of two ways. Some applications use the network to access map and directional information while others work by downloading the map data to the phone and only use the GPS for location and network access for traffic and other real-time updates.
Both of these systems have advantages and disadvantages. The network-based navigations systems rely on network access for map data. These systems include Google Maps Navigation, Bing Maps, and MapQuest 4 Mobile. Network-based navigation systems offer many of the same features as the PND-based applications, including turn-by-turn navigation and real-time updates of traffic and adverse conditions, but some offer features not available in the PND-based systems like the Street View display in Google Maps Navigation.
For occasional users of GPS navigation, network-based navigation apps are an attractive, free alternative to the more expensive PNDs or PND-based applications. The significant drawback, however, of network-based navigation applications is the reliance on the network. Once outside of the data network coverage area, these systems are unusable.
PND-based navigation apps download and store the map data on the smartphone, ensuring access to the maps even when network signal is unavailable. This is especially important outside of major metropolitan areas or anywhere where network coverage is unpredictable. The cost for these applications is roughly on par with the cost to purchase map data for PNDs. While this may be a barrier for infrequent users, it is more likely that infrequent users would choose network-based navigation and anyone considering PND-based navigation would be choosing between a dedicated PND and a PND-based smartphone application.
The advantage of having a dedicated PND is that you don’t commit the smartphone to performing multiple purposes while driving, thus keeping it available for entertainment and communication. Also, for someone who drives a lot and relies heavily on the GPS navigation, having a dedicated device might make more sense.
The PND-based smartphone applications, however, have their own unique advantages. For someone who needs a navigation device in more than one car, having it integrated with the smartphone enhances the convenience significantly. Additionally, the applications can also make use of other functions in the smartphone, such as the ability to email your destination, itinerary, and directions to friends.