## 1 Introduction  
Travel time is a derived demand, which can be generated from various activities that travelers can engage in. Traffic congestion has been increasing for a long time, and it is always concentrated in city centers, where all major activities take place. Additionally, the continuous increment in demand for motorized transport modes--especially private cars--has made the condition worse, requiring remedial action. One effective solution that can help city planners to reduce the number of moving cars in the inner streets of a city is making a kind of restriction on the use of cars inside the city center, such as parking pricing. On the other hand, different solutions can be used in the case of travelers who must travel for a long time to reach the city center and are more willing to use their cars, instead of other available transport modes, such as public transport. The park-and-ride (P&R) system involves constructing parking facilities outside of the city center, and these facilities should be located very close to the public transport stops to encourage mass transit and alleviate the number of cars on the road network. The target group of P&R users are travelers who live outside of a city center and use their private cars for travel. They park their cars in the vicinity of public transport and change to a public transport mode. In this case, a traveler saves time and avoids time spent searching for a parking space. In this system, not only can the severity of congestion be solved, but land can also be saved and utilized for several alternative uses. Moreover, travel time can be optimized when travelers use autonomous vehicles (AVs), instead of their private cars, since activities can be conducted on-board AVs, and AVs have the ability to take full control of a car. It has been suggested that the travel time of AVs is less than that of private cars, because people generally can enjoy their travel time in AVs, unlike in private cars. As mentioned in the literature, each traveler tries to maximize their benefit when they conduct a daily activity plan, such as minimizing travel time, minimizing the cost, making the journey more pleasant, choosing the proper transport mode, and choosing their companions.  
In this particular study, the P&R system and AVs were simulated and integrated with public transport to evaluate the impact of P&R integration system on the overall mobility. This is study is the first study of its kind in Hungary regarding studies on P&R and AV. The objectives of this study are: finding the impacts of P&R system on the travel time of certain people using an integrated approach that connects P&R with the daily activity chain plans of travelers, and the impacts of the AVs on the mobility of the travelers in the developed system. Thus, the impact of the availability of P&R facilities on the activity plans of travelers and the availability of AVs, as a replacement for cars, were presented. In this regard, four scenarios were prepared, which are as follows:  
* A simulation of the existing transport modes of the travelers.
* A simulation of their daily activity plans, when their transport modes were changed to AVs.
* A simulation of the travelers, when P&R facilities were included in their activity chain plans.
* A simulation of their daily activity plans, when both P&R and AVs were included in their activity chain plans.  
The contributions of this study are (1) the inclusion of P&R in the activity chain plan framework, and (2) the study of the impact of including P&R and AVs, together and separately, in the activity chain plans of the travelers on their mobility. The overall contributions were summarized in the simulations of four scenarios, where the utility was maximized.