Control device and method for controlling traveling speed of a vehicle

A method, performed by a control device, for controlling traveling speed of a vehicle for the purpose of maintaining a vehicle speed equal to or lower than a pre-set downhill speed,

• the vehicle comprising:
• one or more auxiliary brake systems configured to brake the vehicle;
• the method comprising the following steps:
• simulating a vehicle speed profile for an upcoming road section if braking at a pre-identified power level by usage of the one or more auxiliary brake systems would currently be requested, thereby obtaining a predicted maximum vehicle speed for the upcoming road section and a predicted time until the vehicle reaches a vehicle speed equal to or within a pre-selected interval of the pre-set downhill speed for said pre-identified power level,
• if the predicted maximum vehicle speed is equal to or below the pre-set downhill speed and the predicted time is below a preselected threshold time limit, requesting braking of the vehicle by the one or more auxiliary brake systems at the pre-identified power level or at an adjusted power level,
• wherein the adjusted power level is derived by adjusting the pre-identified power level to compensate for a difference between said predicted maximum vehicle speed and the pre-set downhill speed.