A vehicle comprising: an engine including an ignition device, a fuel injection device, and an electronically controllable throttle valve; an automatic clutch disengageable and engageable in accordance with a rotation speed of the engine; a driving wheel arranged to be driven by the engine; a driving wheel detection sensor arranged to detect a rotation speed of the driving wheel; a vehicle speed detection sensor arranged to detect a vehicle speed; a traction control device including a slip detection section arranged and programmed to detect a slip of the driving wheel based on the rotation speed of the driving wheel detected by the driving wheel detection sensor and the vehicle speed detected by the vehicle speed detection sensor, and an engine control section arranged and programmed to perform control to decrease an output of the engine when the slip of the driving wheel is detected by the slip detection section; and a clutch state detection device (96,105) arranged to detect a state of the automatic clutch; wherein when the automatic clutch is in an engaged state and the slip of the driving wheel is detected, the engine control section of the traction control device is adapted to execute at least one of ignition retarding control on the ignition device and fuel injection amount decreasing control on the fuel injection device, and also adapted to control to decrease an opening of the throttle valve; characterized in that when the automatic clutch is in a half clutch state and the slip of the driving wheel is detected, the engine control section of the traction control device is adapted to not execute either the ignition retarding control on the ignition device or the fuel injection amount decreasing control on the fuel injection device, and adapted to execute the control to decrease the opening of the throttle valve. an engine including an ignition device, a fuel injection device, and an electronically controllable throttle valve; an automatic clutch disengageable and engageable in accordance with a rotation speed of the engine; a driving wheel arranged to be driven by the engine; a driving wheel detection sensor arranged to detect a rotation speed of the driving wheel; a vehicle speed detection sensor arranged to detect a vehicle speed; a traction control device including a slip detection section arranged and programmed to detect a slip of the driving wheel based on the rotation speed of the driving wheel detected by the driving wheel detection sensor and the vehicle speed detected by the vehicle speed detection sensor, and an engine control section arranged and programmed to perform control to decrease an output of the engine when the slip of the driving wheel is detected by the slip detection section; and a clutch state detection device (96,105) arranged to detect a state of the automatic clutch; wherein when the automatic clutch is in an engaged state and the slip of the driving wheel is detected, the engine control section of the traction control device is adapted to execute at least one of ignition retarding control on the ignition device and fuel injection amount decreasing control on the fuel injection device, and also adapted to control to decrease an opening of the throttle valve; characterized in that when the automatic clutch is in a half clutch state and the slip of the driving wheel is detected, the engine control section of the traction control device is adapted to not execute either the ignition retarding control on the ignition device or the fuel injection amount decreasing control on the fuel injection device, and adapted to execute the control to decrease the opening of the throttle valve.