A travel control system suitable for a construction machine having: left and right traveling devices ; an engine as a power source for the left and right traveling devices ; left and right manipulators for traveling that are operated to drive the left and right traveling devices respectively; a work device for executing work other than traveling; and a manipulator for work that is configured to be operated to drive the work device , the travel control system comprising: a switch for traveling that is provided separately from the left and right manipulators for traveling and configured to output a signal to drive and stop both the left and right traveling devices , a manipulator for steering that is configured to output a signal to change a direction of travel of the traveling devices that are being driven based on an operation of the switch for traveling , and travel control means configured to control the left and right traveling devices based on operation signals output from the switch for traveling and the manipulator for steering , characterised in that the travel control means is further configured to perform steering control by reducing a speed of either the left or right traveling device in accordance with an operation position and operation amount of the manipulator for steering , and lowering a speed of the engine in accordance with the operation amount of the manipulator for steering . left and right traveling devices ; an engine as a power source for the left and right traveling devices ; left and right manipulators for traveling that are operated to drive the left and right traveling devices respectively; a work device for executing work other than traveling; and a manipulator for work that is configured to be operated to drive the work device , the travel control system comprising: a switch for traveling that is provided separately from the left and right manipulators for traveling and configured to output a signal to drive and stop both the left and right traveling devices , a manipulator for steering that is configured to output a signal to change a direction of travel of the traveling devices that are being driven based on an operation of the switch for traveling , and travel control means configured to control the left and right traveling devices based on operation signals output from the switch for traveling and the manipulator for steering , characterised in that the travel control means is further configured to perform steering control by reducing a speed of either the left or right traveling device in accordance with an operation position and operation amount of the manipulator for steering , and lowering a speed of the engine in accordance with the operation amount of the manipulator for steering . a switch for traveling that is provided separately from the left and right manipulators for traveling and configured to output a signal to drive and stop both the left and right traveling devices , a manipulator for steering that is configured to output a signal to change a direction of travel of the traveling devices that are being driven based on an operation of the switch for traveling , and travel control means configured to control the left and right traveling devices based on operation signals output from the switch for traveling and the manipulator for steering , characterised in that the travel control means is further configured to perform steering control by reducing a speed of either the left or right traveling device in accordance with an operation position and operation amount of the manipulator for steering , and lowering a speed of the engine in accordance with the operation amount of the manipulator for steering . reducing a speed of either the left or right traveling device in accordance with an operation position and operation amount of the manipulator for steering , and lowering a speed of the engine in accordance with the operation amount of the manipulator for steering . <EOS>