A public transport route planner is an intermodal journey planner , Typically accessed via the web That Provides information about available public transport services. The application prompts a user to input a origin and a destination, and then uses algorithms to find a good road between the two on public transit services. Time of travel may be constrained to either time of departure or arrival and other routing preferences may be specified as well.
An intermodal journey planner supports intermodal journeys ie using more than one modes of transport , such as cycling, rapid transit , bus , ferry , etc. Many road planners supporting door-to-door timetable while others only work entre stops on the transportation network , Such As stations, airports or bus stops .
One of the first digital public transport was developed by Eduard Tulp, a student at the University of Amsterdam at Atari PC.  He was hired by the Dutch Railways to build a digital journey planner for the train services. In 1990 the first digital day-to-day planner for the Dutch Railways (on diskette) was sold to be installed on PC’s and computers for off-line consultation.        This paper describes the evolution of the state of the art.
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. The first published version was sold for the timetable period 1989/1990.   
Other European countries soon followed with their own day planners.
Data exchange standards
For transit route planners to work, transit schedule data must always be kept up to date. To facilitate data exchange and interoperability between different trip planners, several data formats have emerged.
The General Transit Feed Specification , developed in 2006,  is now used by hundreds of transit agencies around the world.
In the European Union all public transport passengers have the obligation to provide information under the EU railway timetable data exchange format.    In other parts of the world there similar exchange standards. 
- Google Transit
- Transport Direct
- Jump up^ Trouw, 05/06/1998
- Jump up^ 175 years of travel information, chapter: Wel of geen vervoer?
- Jump up^ http://kinkrsoftware.nl/contrib/Artikel16b.2a/tulp.pdf, Tulp, Eduard,Searching time-table networks, proefschriftVrije Universiteit Amsterdam, 1991
- Jump up^ Tages-Anzeiger, 14 February 2009, p. 14,Hans-Jakob Tobler gestorben. Source:Argus Medienbeobachtung (through archive.org)(PDF file; 70 kB).
- Jump up^ Alexandria. Entry Finajour 1.02 Sommer 1989.
- Jump up^ Computerwoche:Schweiz: Fahrpläne im Videotex, 22 September 1989 («Schon auf den Fahrplanwechsel in diesem Frühjahr war die PC-Schweizerischen version Zugfahrplans von der Firma Finajour veröffentlicht worden Inzwischen wurden gut tausend Exemplare zu einem Stückpreis von hundert Franken verkauft .“)
- Jump up^ “Pioneering Open Data Standards: The GTFS Story” . Beyondtransparency.org . Retrieved 2017-05-10 .
- Jump up^ NeTEx
- Jump up^ SOA architecture for complying with EU railway timetable data exchange format (link in chapter Präsentationen)
- Jump up^ Transnational exchange of timetable and GIS data as a basis for cross-border ITS services
- Jump up^ Transit Schedule Data Exchange Architecture