fix #14621

src/microsim/cfmodels/MSCFModel_IDM.cpp

@@ -135,13 +135,27 @@ MSCFModel_IDM::insertionFollowSpeed(const MSVehicle* const v, double speed, doub
 }
 
 
+double
+MSCFModel_IDM::insertionStopSpeed(const MSVehicle* const veh, double speed, double gap) const {
+    // we want to insert the vehicle in an equilibrium state
+    double result = MSCFModel::insertionStopSpeed(veh, speed, gap);
+    int i = 0;
+    while (result - speed < -ACCEL2SPEED(myDecel) && ++i < 10) {
+        speed = result;
+        result = MSCFModel::insertionStopSpeed(veh, speed, gap);
+    }
+    return result;
+}
+
+
 double
 MSCFModel_IDM::stopSpeed(const MSVehicle* const veh, const double speed, double gap, double decel, const CalcReason /*usage*/) const {
     applyHeadwayPerceptionError(veh, speed, gap);
     if (gap < 0.01) {
         return 0;
     }
     double result = _v(veh, gap, speed, 0, veh->getLane()->getVehicleMaxSpeed(veh), false);
+    //std::cout << SIMTIME << " stopSpeed speed=" << speed << " gap=" << gap << " decel=" << decel << " result=" << result << "\n";
     if (gap > 0 && speed < NUMERICAL_EPS && result < NUMERICAL_EPS) {
         // ensure that stops can be reached:
         //std::cout << " switching to krauss: " << veh->getID() << " gap=" << gap << " speed=" << speed << " res1=" << result << " res2=" << maximumSafeStopSpeed(gap, speed, false, veh->getActionStepLengthSecs())<< "\n";

src/microsim/cfmodels/MSCFModel_IDM.h

@@ -137,6 +137,16 @@ class MSCFModel_IDM : public MSCFModel {
      */
     double insertionFollowSpeed(const MSVehicle* const veh, double speed, double gap2pred, double predSpeed, double predMaxDecel, const MSVehicle* const pred = 0) const;
 
+    /** @brief Computes the vehicle's safe speed for approaching an obstacle at insertion without constraints
+     *         due to acceleration capabilities and previous speeds.
+     * @param[in] veh The vehicle (EGO)
+     * @param[in] speed The vehicle's speed
+     * @param[in] gap The (netto) distance to the the obstacle
+     * @return EGO's safe speed for approaching a non-moving obstacle at insertion
+     * @see stopSpeed() and insertionFollowSpeed()
+     *
+     */
+    double insertionStopSpeed(const MSVehicle* const veh, double speed, double gap) const;
 
     /** @brief Returns the minimum gap to reserve if the leader is braking at maximum (>=0)
      * @param[in] veh The vehicle itself, for obtaining other values