| ride comfort index at time t |

| peak value of acceleration in T = (t − 3,t) (3 seconds just before time t) |

| peak absolute value of deceleration in T |

| average value of jerk in T |

| effective value of jerk in the case of positive value of j(T) |

| effective value of jerk in the case of negative value of j(T) |

| error term |

| constant term |

| partial regression coefficient |