CRUISE CONTROLLER

A computer system (100) comprising processing circuitry (110) is presented. The processing circuitry (110) is configured to evaluate, based on topography data (27) of an upcoming road segment (21, 22), use of upcoming topography to achieve a target speed range (232) of a vehicle (10) operating in a topography fuel efficiency mode. The processing circuitry (110) is further configured to determine all trailing vehicles within a predetermined range are operating in a fuel efficiency mode corresponding to the topography fuel efficiency mode and responsive to determining that all trailing vehicles (30) within the predetermined range are operating in a propulsion mode (33) corresponding to the topography fuel efficiency mode, permit a current speed (242) of the vehicle (10) to temporarily deviate below the target speed range (232) of the vehicle (10) and to use the upcoming topography to achieve the target speed (232).