In a vehicle driving assist system, an obstacle detection device detects
an obstacle present in each of two obstacle detection directions with
respect to a subject vehicle; and a TTC calculation device calculates a
TTC between the subject vehicle and each of obstacles based on detection
results of the obstacle detection device. A lateral reaction force
control device controls a reaction force generated at a vehicle operation
equipment for drive operation in a lateral direction of the subject
vehicle based on a first TTC which is smaller in the TTCs calculated in
the TTC calculation device; and a longitudinal reaction force control
device controls a reaction force generated at a vehicle operation
equipment for drive operation in a longitudinal direction based on a
second TTC which is larger in the TTCs.