Driving assistance system

A driving assistance system that executes deceleration assistance of a host vehicle when a relative state between the host vehicle and a deceleration object ahead of the host vehicle satisfies a preset deceleration assistance start condition, the driving assistance system comprising:

• a brake operation detection unit configured to detect whether a brake operation is performed by a driver of the host vehicle during the deceleration assistance;
• a deceleration gradient setting unit configured to, when a brake operation is performed by the driver during the deceleration assistance, set a deceleration gradient to stop the deceleration assistance based on at least one of presence or absence of a forward obstacle ahead of the host vehicle, a relative state between the host vehicle and the forward obstacle, and a road environment in which the host vehicle travels;
• and
• a deceleration assistance stop unit configured to, when a brake operation is performed by the driver during the deceleration assistance, stop the deceleration assistance of the host vehicle along the deceleration gradient set by the deceleration gradient setting unit.