# Interdisciplinary Urban Tunnel Control within Smart Cities
###### Abstract  
Nowadays, urban road tunnels are considered to be independent entities within a city. Their interactions with the rest of the city and vice versa are usually not considered and, if they are, are only considered in a limited way (for example, through the nearest traffic controller). Typically, only the traffic parameters and not the environmental impacts are considered. This paper has two major objectives. First, we provide a systemic view on a road urban tunnel. The major focus is on the interfaces between the tunnel and the rest of the city and the way they will be managed. We are providing a tool to take into consideration a sustainable development of a tunnel (i.e., not only traffic flow parameters such as average speed, but also environmental and societal characteristics). This model expresses the actual traffic situation in a monetary form (i.e., cost of congestions). The second objective is to provide a new road urban tunnel control approach that follows the original methodology and systemic view described in the paper. If the tunnel is controlled autonomously, which corresponds to the current state-of-the-art in many cities, the algorithm decides to close it based on only local parameters. However, the proposed new algorithm takes into consideration not only the traffic situation in the tunnel (expressed by the parameter traffic density), but also the actual traffic situation within the city (expressed by its level of service (LOS)). This allows more environmentally, socially and economically sustainable oriented road urban tunnel management. The described algorithm is demonstrated on a specific example of the tunnel complex Blanka in Prague. r Article Interdisciplinary Urban Tunnel Control within Smart Cities [PERSON] et al. (2021), [PERSON]; [PERSON] [PERSON] Interdisciplinary Urban Tunnel Control within Smart Cities. 17 November 2021 19 November 2  
The main contribution of this paper is in two aspects. First, the role of an urban road tunnel within a city is discussed. The topic of smart cities looks at quality of life and sustainability usually through better integration of their components [1]. A tunnel is, however, nowadays considered an independent entity. For this reason, we discuss the different dimensions of the interface between a tunnel and a city. We provide a target function as well as a mechanism to express the traffic situation in monetary terms. This allows better integration. The second contribution of this paper is a new tunnel control algorithm based on the systemic approach described above. This algorithm takes into consideration the future state of traffic flow in the tunnel. It is based on the measured parameter traffic density in the tunnel but also as on the level of service (LOS) of traffic in the rest of the city. Thus, the control is adopted based not only on the tunnel performance itself but also on the rest of the city. A parameter cost of congestions is explained and shall be used directly to evaluate the control strategies. This parameter also demonstrates the monetary influence of current tunnel control strategies (namely closing the tunnel for road traffic) on the city. This paper has the following structure. First, we address an urban road tunnel from the system theory perspective. The target function of any control or management strategy is discussed. Also, the topic of complexity and interface to the adjacent (smart) city components and processes is addressed. The influence of tunnel control on the adjacent traffic is supported by results from a project GLOMODO (global model of traffic) on a case study from Prague. The theory of expressing the deterioration of traffic performance indicators is expressed through monetary terms (i.e., cost of congestions). In Section 3, we discuss a new urban tunnel control algorithm. This algorithm is based on the traffic flow theory and aims on keeping the flow stable (fluid) while taking into consideration the outside traffic of the tunnel.