Method for cooperatively generating and managing a travel plan for a vehicle by means of at least two user devices (2.1, 2.2, 4), wherein (a) a starting position and a destination position are sensed by a first of the at least two user devices (2.1, 2.2, 4) and the travel plan is generated, wherein the travel plan comprises at least one route from the starting position to the destination position and a list of planning objects which are assigned to the route, (b) a participant enquiry is generated for all the further of the at least two user devices (2.1, 2.2, 4) and transmitted to the respective further user device (2.1, 2.2, 4), wherein the participant enquiry is outputted by the respective further user device (2.1, 2.2, 4) and a user input is sensed as an acceptance, wherein the first user device (2.1, 2.2, 4) and the further user devices (2.1, 2.2, 4), for which an acceptance has been sensed, are participant devices (2.1, 2.2, 4), (c) a display is generated and outputted by a participant device (2.1, 2.2, 4) on the basis of the travel plan, wherein the display comprises a user interface, and travel plan supplementary data are acquired by means of an input unit (2.1b, 2.2b, 4) of the participant device (2.1, 2.2, 4), wherein the route is assigned at least one further planning object or a planning object assigned to the route is removed, (d) step (c) is repeated for as long as further travel plan supplementary data are acquired, wherein the acquired travel plan supplementary data are updated, and until publication of a proposal by the user, (e) the travel plan is updated on the basis of the acquired travel plan supplementary data, wherein the route and/or the list of the planning objects are newly generated, (f) a control signal is generated on the basis of the updated travel plan and transmitted at least to a navigation device of the vehicle and (g) steps (c) to (f) are repeated with the updated travel plan as long as further travel plan supplementary data are acquired in step (c) and (d), characterized in that a specific participant device (2.1, 2.2, 4) is operated as a driver device (2.1, 2.2, 4) and the other participant devices (2.1, 2.2, 4) are operated as passenger devices (2.1, 2.2, 4), on the basis of the travel plan supplementary data, a confirmation enquiry is generated and outputted by the driver device (2.1, 2.2, 4), an acceptance of the confirmation enquiry is sensed by the driver device (2.1, 2.2, 4) and in step (e) the travel plan is updated subject to the sensed acceptance. (a) a starting position and a destination position are sensed by a first of the at least two user devices (2.1, 2.2, 4) and the travel plan is generated, wherein the travel plan comprises at least one route from the starting position to the destination position and a list of planning objects which are assigned to the route, (b) a participant enquiry is generated for all the further of the at least two user devices (2.1, 2.2, 4) and transmitted to the respective further user device (2.1, 2.2, 4), wherein the participant enquiry is outputted by the respective further user device (2.1, 2.2, 4) and a user input is sensed as an acceptance, wherein the first user device (2.1, 2.2, 4) and the further user devices (2.1, 2.2, 4), for which an acceptance has been sensed, are participant devices (2.1, 2.2, 4), (c) a display is generated and outputted by a participant device (2.1, 2.2, 4) on the basis of the travel plan, wherein the display comprises a user interface, and travel plan supplementary data are acquired by means of an input unit (2.1b, 2.2b, 4) of the participant device (2.1, 2.2, 4), wherein the route is assigned at least one further planning object or a planning object assigned to the route is removed, (d) step (c) is repeated for as long as further travel plan supplementary data are acquired, wherein the acquired travel plan supplementary data are updated, and until publication of a proposal by the user, (e) the travel plan is updated on the basis of the acquired travel plan supplementary data, wherein the route and/or the list of the planning objects are newly generated, (f) a control signal is generated on the basis of the updated travel plan and transmitted at least to a navigation device of the vehicle and (g) steps (c) to (f) are repeated with the updated travel plan as long as further travel plan supplementary data are acquired in step (c) and (d),