Method for tracking vehicles which are liable for a toll in a toll system which has at least one data processing apparatus (205, 206) being in communication with an offense database and at least one stationary control apparatus on the road side, wherein in the offense database are stored first toll violation notices associated in each case with number plates of vehicles which are liable for the toll, comprising the steps: - detecting at least one number plate of a vehicle which is liable for the toll by means of the stationary control apparatus on the road side, - forming a control data set, which comprises the number plate of the detected vehicle which is liable for the toll and its point in time of detection, on the part of the control apparatus on the road side, - detecting on the part of the data processing apparatus (205, 206) whether in the offense database for the detected number plate a first toll violation notice, detected prior to the point in time of detection, is present, wherein the toll violation notices stored in the offense database are specified by prior detection of at least one number plate of a vehicle which is liable for the toll by means of a control apparatus on the road side and the prior determination whether a toll violation of the vehicle which is liable for the toll has occurred, - if a first toll violation notice for the detected number plate is present in the offense database, associating the first toll violation with the control data set on the part of the data processing apparatus, wherein - the control data set and at least the first toll violation notice associated therewith are transmitted to a mobile display device and the control data set and at least the first toll violation notice associated therewith are displayed on the mobile display device, - wherein the mobile display device is comprised by a control vehicle for pursuing detected vehicles which are liable for the toll, is carried therein or is provided thereby and/or the mobile display device is comprised by a mobile device, preferably mobile computer, tablet computer or smart phone. - detecting at least one number plate of a vehicle which is liable for the toll by means of the stationary control apparatus on the road side, - forming a control data set, which comprises the number plate of the detected vehicle which is liable for the toll and its point in time of detection, on the part of the control apparatus on the road side, - detecting on the part of the data processing apparatus (205, 206) whether in the offense database for the detected number plate a first toll violation notice, detected prior to the point in time of detection, is present, wherein the toll violation notices stored in the offense database are specified by prior detection of at least one number plate of a vehicle which is liable for the toll by means of a control apparatus on the road side and the prior determination whether a toll violation of the vehicle which is liable for the toll has occurred, - if a first toll violation notice for the detected number plate is present in the offense database, associating the first toll violation with the control data set on the part of the data processing apparatus, wherein - the control data set and at least the first toll violation notice associated therewith are transmitted to a mobile display device and the control data set and at least the first toll violation notice associated therewith are displayed on the mobile display device, - wherein the mobile display device is comprised by a control vehicle for pursuing detected vehicles which are liable for the toll, is carried therein or is provided thereby and/or the mobile display device is comprised by a mobile device, preferably mobile computer, tablet computer or smart phone.