There are three major demonstrations within the CityMobil project the Castellón demonstrator (Hybrid transport system) is explained below.

Castellón (Hybrid transport system) - Guided bus/tramway system

The objective of the Castellón Demonstrator is the implementation of a hybrid transport system connecting the cities of Castellón – the university and city centre – and Benicassim, at the seaside. At this moment the connection between the University and the city centre if fully operational
The system is structured around two corridors, with more than 40 kilometres, in which a reserved platform for the public transport vehiclesis built. On this platform: an hybrid system of guided bus/tramway combination of cargo capacity, accessibility, speed and regularity of a railway-based solution with the flexibility, adaptability and smaller costs of a road-based system. the vehicles travel through a reserved platform combined with shared infrastructure. at intersections, the bus/tramway is given priority over the private traffic.
The guided vehicle systems involve taking the steering of the bus away from the bus driver in the case of Castellón, part of the route. This eliminate the need for any lateral movement of the bus within a lane of traffic. A bus is generally approximately 2.5 m wide, but a bus lane is usually 3.75 m or even 4 m wide to allow for this lateral movement. A guided bus system, provides opportunities to implement dedicated bus ways where road space is in short supply and, where conventional bus lanes could be impractical. It also provides opportunities – by means of automated docking - to improve physical access to the bus by minimising the vertical and horizontal gaps between the bus stop and the bus.  The Castellón demonstration makes use of electrical traction vehicles with guidance systems to circulate over a reserved platform. The vehicles are powered through a tramway catenary, having in addition another secondary power supply system to be used in the historical centre of the city, where it is not possible to have an aerial power supply system.