# Multi-Objective Routing and Categorization of Urban Network Segments for Cyclists
## 1 Introduction  
### Purpose of the Study  
Cycling is becoming an increasingly popular transport mode in urban environments because of its health benefits for users and its competitive door-to-door travel times for short distances [1]. It is also proposed by many [2] as a solution to the energy crisis and the rising cost of conventional vehicles. However, many cities provide inadequate infrastructure for safe, fast, and pleasant cycling, forcing travelers to opt for private cars [3]. The European Commission has proposed a review of urban infrastructure to encourage walking and cycling in cities [4]. In a recent meeting, EU transport ministers highlighted cycling as an environmentally friendly mode of transportation. The meeting also noted that cycling is considered an efficient way of land use in urban areas, as it is healthy, eco-friendly, and inexpensive. In addition, guidance has been developed to support cycling development projects within the EU [5]. However, cyclists commuting to work face several challenges when using the city's road network. According to a survey conducted by Cycle2 Work [6], some of the most common challenges that cyclists face are the driving behavior of conventional vehicles, inadequate road conditions, lack of bicycle infrastructure, extreme weather conditions, and lack of motivation among others. In some cities, bicycle users are not welcomed due to the lack of dedicated bike lanes and other infrastructure that supports their needs [7]. Given these considerations, this study will analyze how cyclists categorize urban streets and what elements encourage them to choose their route choices with the goal being to create a cyclists' navigation model within urban networks. Given the several factors that can impact the route decisions of cyclists, this model will be solved using multi-objective optimization techniques. This analysis and the definition of cyclists' route choice characteristics in a systematic way is timely for several reasons:  
* Safety: Many urban roads are designed for cars, with a limited focus on the safety of cyclists and pedestrians. By categorizing roads and designating routes in a way that prioritizes cyclist safety, cities can help reduce the risk of accidents, making cycling a safer and more attractive transport option [8]. * Access: For many people, cycling is a convenient and economical way to travel, particularly in urban areas where parking and traffic can be a challenge [5]. By providing clear and well-defined routes designed with cyclists in mind, cities can make it easier for cyclists to reach their destinations efficiently [9]. * Sustainability: Encouraging more people to cycle can also support sustainability efforts by reducing greenhouse gas emissions [1]. By designing cities in a way that supports cycling and other sustainable modes of transport, we can work towards a more sustainable future. * Traffic congestion: Dealing with the constant influx of car users on the urban network by constantly upgrading it has been shown to feed a vicious cycle of congestion problems [10]. In contrast, improvements in micromobility and public transport can reduce traffic congestion in densely populated urban areas. This study develops a method for computing the optimal routes for cyclists when traveling from an origin to a destination point in an urban network. The study focuses first on understanding the road characteristics that cyclists give more importance to when choosing their route. A study area (Athen's city center) and two points of origin and destination are used for testing purposes. For this study area, all the accessible points are identified based on the criteria that have been explored. It is noted that in this study, the choice of cyclists among all the elements of the urban network (roads, sidewalks, pedestrian crossings, and cycle lanes) will also be investigated. For all these points, data on travel characteristics are collected.