diff --git a/simulator/autoware_simple_planning_simulator/include/autoware/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.hpp b/simulator/autoware_simple_planning_simulator/include/autoware/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.hpp
index d878ef01c0536..fa3eafa78a710 100644
--- a/simulator/autoware_simple_planning_simulator/include/autoware/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.hpp
+++ b/simulator/autoware_simple_planning_simulator/include/autoware/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.hpp
@@ -79,7 +79,6 @@ class SimModelDelaySteerVel : public SimModelInterface
   const double steer_lim_;       //!< @brief steering limit [rad]
   const double steer_rate_lim_;  //!< @brief steering angular velocity limit [rad/s]
   const double wheelbase_;       //!< @brief vehicle wheelbase length [m]
-  double prev_vx_ = 0.0;
   double current_ax_ = 0.0;
 
   std::deque<double> vx_input_queue_;     //!< @brief buffer for velocity command
diff --git a/simulator/autoware_simple_planning_simulator/src/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.cpp b/simulator/autoware_simple_planning_simulator/src/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.cpp
index 66d42d4719bf0..89d9b573fa96d 100644
--- a/simulator/autoware_simple_planning_simulator/src/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.cpp
+++ b/simulator/autoware_simple_planning_simulator/src/simple_planning_simulator/vehicle_model/sim_model_delay_steer_vel.cpp
@@ -83,9 +83,9 @@ void SimModelDelaySteerVel::update(const double & dt)
   delayed_input(IDX_U::STEER_DES) = steer_input_queue_.front();
   steer_input_queue_.pop_front();
   // do not use deadzone_delta_steer (Steer IF does not exist in this model)
+  const double prev_vx = state_(IDX::VX);
   updateRungeKutta(dt, delayed_input);
-  current_ax_ = (input_(IDX_U::VX_DES) - prev_vx_) / dt;
-  prev_vx_ = input_(IDX_U::VX_DES);
+  current_ax_ = (state_(IDX::VX) - prev_vx) / dt;
 }
 
 void SimModelDelaySteerVel::initializeInputQueue(const double & dt)