This includes the planning phase before embarking on a journey as well as the journey itself, starting with entering the vehicle and continuing through any necessary connections (including between public and individual transport) until the destination is reached.
DPI systems can deliver the most up-to-date information possible on current operating conditions and the predicted course of a journey, providing passengers with reliable data for planning and travelling their route. They provide information on
- the next departures,
- the destination,
- intermediate stops and
- special operational circumstances and services.
- They can warn in advance of foreseeable delays,
- suggest alternative routes (detours) and additional transit services,
- and give passengers and drivers information on connections.
Passengers with reduced mobility depend on receiving special information, since it is unusual for all parts of the transit network to provide disabled access. The internet (stationary or mobile, e.g. smart phone) provides passengers access to such information.
In addition, visual media at (larger) stops and station access points (e.g. in department stores and public buildings that offer direct access to public transport) can provide up-to-date information.
DPI is only possible when data on current operating conditions and their magnitude of influence are continuously fed into the system.
For each vehicle about which information is provided, data on its current location must be captured (e.g. using GPS – Global Positioning System) in order to give accurate arrival and departure times.
This is done, for example, using an intermodal transport control system (ITCS), one of whose basic functions is the ongoing comparison of scheduled and actual arrivals and departures.
On-site DPI components must be continuously supplied with correct and up-to-date data, optimally placed, designed for good visibility and legibility, able to offer the passenger clearly formulated information, and integrated in a technical system for equipment monitoring and a corresponding (easily implemented) servicing and repair scheme.
Intermodal travel planning with an intelligent combination of different modes of transport is especially important in advance of a journey – in addition to current arrival and departure times, passengers need to know about the capacity of park-and-ride lots, for instance, or the availability of car and bicycle sharing programs. And this information must be continuously and automatically updated in the course of the journey. Here it is essential that mobile devices and stationary information systems offer reliable, identical information that corresponds with the current transport situation. Only when this is achieved will an intermodal navigation system truly meet the needs of customers.