Journey planner

A journey planner, trip planner, or route planner is a specialized search engine used to find an optimal means of travelling between two or more given locations, sometimes using more than one transport mode. Searches may be optimized on different criteria, for example fastest, shortest, fewest changes, cheapest. They may be constrained, for example, to leave or arrive at a certain time, to avoid certain waypoints, etc. A single journey may use a sequence of several modes of transport, meaning the system may know about public transport services as well as transport networks for private transportation.

Trip planning or journey planning is sometimes distinguished from route planning, which is typically thought of as using private modes of transportation such as cycling, driving, or walking, normally using a single mode at a time. Trip or journey planning, in contrast, would make use of at least one public transport mode which operates according to published schedules; given that public transport services only depart at specific times (unlike private transport which may leave at any time), an algorithm must therefore not only find a path to a destination, but seek to optimize it so as to minimize the waiting time incurred for each leg. In European Standards such as Transmodel, trip planning is used specifically to describe the planning of a route for a passenger, to avoid confusion with the completely separate process of planning the operational journeys to be made by public transport vehicles on which such trips are made.

Trip planners have been widely used in the travel industry since the 1970s, by booking agents. The growth of the internet, the proliferation of geospatial data, and the development of information technologies generally has led to the rapid development of many self-service app or browser-based, on-line intermodal trip planners.

A trip planner may be used in conjunction with ticketing and reservation systems. As an example, the largest single use of journey planning technology is used in Great Britain in railway booking systems, often referred to as RTJP (Real Time Journey Planner), which processes the data between two or multiple points. This can be viewed on National Rail's official website.

In the late 1980s and early 1990s, some national railway operators and major metropolitan transit authorities developed their own specialized trip planners to support their customer enquiry services. These typically ran on mainframes and were accessed internally with terminals by their own staff in customer information centers, call centers, and at ticket counters in order to answer customer queries. The data came from the timetable databases used to publish printed timetables and to manage operations and some included simple route planning capabilities. The HAFAs timetable information system developed in 1989 by the German company Hacon, (now part of Siemens AG) is an example of such a system and was adopted by Swiss Federal Railways (SBB) and Deutsche Bahn in 1989. The "Routes" system of London Transport, now TfL, in use before the development of the on-line planner and covering all public transport services in London, was another example of a mainframe OLTP journey planner and included a large database of tourist attractions and popular destinations in London.

In the 1990s with the advent of personal computers with sufficient memory and processor power to undertake trip planning (which is relatively expensive computationally in terms of memory and processor requirements), systems were developed that could be installed and run on minicomputers and personal computers. The first digital public transport trip planner systems for a microcomputer was developed by Eduard Tulp, an informatica student at the Amsterdam University on an Atari PC. He was hired by the Dutch Railways to build a digital trip planner for the train services. In 1990 the first digital trip planner for the Dutch Railways (on diskette) was sold to be installed on PC's and computers for off-line consultation. The principles of his software program was published in a Dutch university paper in 1991 This was soon expanded to include all public transport in the Netherlands.

Another pioneer was Hans-Jakob Tobler in Switzerland. His product Finajour, which ran for PC DOS and MS-DOS was the first electronic timetable for Switzerland ^{[citation needed]}. The first published version was sold for the timetable period 1989/1990. Other European countries soon followed with their own journey planners.

A further development of this trend was to deploy trip planners onto even smaller platforms such as mobile devices, a Windows CE version of Hafas was launched in 1998 compressing the application and the entire railway timetable of Deutsche Bahn into six megabytes and running as a stand-alone application.