How to fix C++ object slicing in a mixed array?

Question

In my C++ I would like to print out cars and lorrys (derived from the vehicle class). Here are the definitions of the classes:

class Vehicle
{
    int speed;
    int entryTime;
    int currentPositionInLane;
    int minimumFollowingDistance;
public:

    virtual void print() const {
        std::cout << "speed: " << speed << std::endl;
        std::cout << "entryTime: " << entryTime << std::endl;
        std::cout << "currentPositionInLane: " << currentPositionInLane << std::endl;
        std::cout << "minimumFollowingDistance: " << minimumFollowingDistance << std::endl;
    }
};
 
class Car : public Vehicle
{
    int currentLane;
public:
    Car(int, int, int, int, int);
    void pass(const Vehicle&);
    void print() const {
        Vehicle::print();
        std::cout << "currentLane: " << currentLane << std::endl;
    }
};
class Lorry: public Vehicle
{
public:
    Lorry(int speed, int entryTime, int currentPositionInLane, int minimumFollowingDistance): Vehicle(speed, entryTime, currentPositionInLane, minimumFollowingDistance){}
};

class Road
{
    double updateFrequency;
    double currentTime;
    Vehicle* vehicles;
    int vehicleCount;
public:
    Road();
    void update();
    bool checkIfFinished();
    void checkForUserInterrupt();
    void saveToFile();
    bool setCurrentTime(double);
    bool setUpdateFrequency(double);
    void addVehicle(const Vehicle& vehicle);

    void print();
};

The print method of the Road class:

void Road::print() {
std::cout << "updateFrequency: " << updateFrequency <<std::endl;
std::cout << "currentTime: " << currentTime << std::endl;
std::cout << std::endl << "The vehicles on the road: " << std::endl << std::endl;
for (int i = 0; i < vehicleCount; i++)
{
    vehicles[i].print();
    std::cout << std::endl;
}

}

My problem is that despite the print method of the base class being virtual, the print method of the car class never gets called. As far as I understand the problem is object slicing. That's why I pass the Lorry or Car as a Vehicle reference in the addVehicle method, however that doesn't fix the issue. I suspect that the problem is in the addVehicle function and somehow I should overwrite the = operator:

void Road::addVehicle(const Vehicle& vehicle) {
if (vehicles == nullptr) {
    vehicles = new Vehicle[1];
    vehicles[0] = vehicle;
    vehicleCount = 1;
}
else {
    Vehicle* temp = new Vehicle[vehicleCount + 1];
    for (int i = 0; i < vehicleCount; i++) {
        temp[i] = vehicles[i];
    }
    temp[vehicleCount] = vehicle; // I think this is the line causing the issue
    vehicleCount++;
    delete[] vehicles;
    vehicles = temp;
}

}