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Recently, a new shared micromobility service has become popular in cities. The service is supplied by a new vehicle, the e-scooter, which is equipped with a dockless security system and electric power assistance. The relatively unregulated proliferation of these systems driven by the private sector has resulted in numerous research questions about their repercussions. This paper reviews scientific publications as well as evaluation reports and other technical documents from around the world to provide insights about these issues. In particular, we focus on mobility, consumer perception and environment. Based on this review, we observe several knowledge needs in different directions: deeper comprehension of use patterns, their function in the whole transport system, and appropriate policies, designs and operations for competitive and sustainable shared e-scooter services.

Autonomous vehicles (AVs) are becoming a reality and may integrate with existing public transport systems to enable the new generation of autonomous public transport. It is vital to understand what are the alternatives for AV integration from different angles such as costs, emissions, and transport performance. With the aim to support AV integration in public transport, this paper takes a typical European city as a case study for analyzing the impacts of different AV integration alternatives. A transport planning model considering AVs is developed and implemented, with a methodology to estimate the costs of the transport network. Traffic simulations are conducted to derive key variables related to AVs. An optimization process is introduced for identifying the optimal network configuration based on a given AV integration strategy, followed by the design of different AV integration scenarios, simulation, and analyses. With the proposed method, a case study is done for the city of Uppsala with presentation of detailed cost results together with key traffic statistics such as mode share. The results show that integrating AVs into public transport does not necessarily improve the overall cost efficiency. Based on the results and considering the long transition period to fully autonomous vehicles, it is recommended that public transport should consider a gradual introduction of AVs with more detailed analysis on different combination and integration alternatives of bus services and AVs.

The arrival of automated vehicles could significantly reduce the operating cost of mobility services. This fact has encouraged researchers to propose door-to-door services instead of the current fixed routes. However, a comparison between these two alternatives is required in order to identify when (depending on the development degree of the automated vehicles) and where (depending on the characteristics of the area of service) the implementation of each service is the most competitive solution. This research compares the two types of transit services to supply first/last-mile solutions in suburban areas. By means of an analytical approach, the results show that fixed routes remain the most efficient alternative unless the new technology reaches a certain degree of development that allows a high reduction of operating costs. In this case, the applicability of door-to-door services will significantly increase under certain circumstances: small areas of service, short distance trips and high values of time.

This paper analyzes the new operations induced by the energy range limitation in battery electric bus (BEB) systems to ensure the service provision along the whole day. An operating model has been developed to estimate the number of resources to be deployed (extra vehicles and charging facilities) for two charging schemes: charging at bus garage facility and opportunity charging at on-street chargers. Firstly, the model calculates the entrance and exit time of buses in service assuming an unlimited battery capacity, caused by demand and headway variations in different time periods along day. Then, based on the previous results, the model estimates the moment when vehicles will run out of energy and proposes a charging schedule as well as new vehicle movements between chargers, bus garage and routes to maintain the targeted headway. Consequently, the model is able to calculate the number of resources needed and the total cost for a given route and battery size, allowing cost and performance comparison to diesel and hybrid powertrains. The estimated results in two bus routes in Barcelona indicate that the purchasing cost of BEB vehicles (670,000 euros/veh for articulated, 500,000Euros/veh for standard vehicles, both depreciated over a lifetime of 15 years), battery packs (231 Euro/kWh purchased, depreciated over a lifetime of 10 years), as well as the investment in chargers, are still high to clearly justify their cost-competitiveness against diesel or hybrid counterparts. Nevertheless, if the acquisition cost of both vehicles and battery pack are only reduced by 9%, the BEB technology may present cost savings for transit agencies. It only happens if the fleet size is as large as the corresponding to diesel and hybrid technologies. Opportunity charging is resulted to be more cost- efficient than charging at bus garage for small battery packs, routes with acceptable time headway adherence and, specially, when fast chargers are located very close to terminal stops. Nevertheless, when the real bus route design and operation do not fulfill these standards, charging scheme at bus garage is preferable. This research was partly developed within the ZeEUS project framework. ZeEUS was co-funded by the European Commission under the 7th Research and Technological Development Framework Programme (FP7), Directorate-General for Mobility and Transport under grant agreement n°605485. Peer Reviewed Objectius de Desenvolupament Sostenible::13 - Acció per al Clima Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant

This paper evaluates the impact of vehicle automation and electrification on the applicability of fixed routes and door-to-door services to supply a feeder transit solution in suburban areas. These technologies will modify the current cost structure of the bus system depending on how mature they are, reducing operating costs and increasing capital costs. By means of a continuum approximation model, we evaluate the performance for users and agency of the two feeder strategies in different scenarios of technological development. The results show that automation has the main impact on the applicability between the two feeder alternatives while the effects of electrification are considerably smaller. The future applicability of door-to-door trips reaches wider ranges, although this change is especially significant under some circumstances of technology, service area and users. The expansion of this range is relevant in case the automated bus is mature enough (high reduction of operating cost and low vehicle acquisition price), the areas are small, the trips are short and the value of time is high. However, the results reveal that fixed routes will remain a competitive feeder solution in a wide range of scenarios. We identify that the demand density threshold grows sharply in front of any reduction of agency costs once its value is around 200–300 pax/km2-h. Therefore, flexible services will gain applicability especially in environments that allow reaching this threshold. The research was funded by Stockholm County Council (grant no. 20170901), KTH Integrated Research Lab (ITRL) and TRENoP Strategic Research Area.

This paper extends the discussion about the bus network design in face of the mobility patterns associated with different degrees of urban dispersion. Based on an analytical approach, a comparison of total costs among different network structures is made for a ring-radial city, which is the other most common regular city layout. The results clarify what structure is the best solution for different scenarios of dispersion and city and transport characteristics. Simultaneously, the effect of the street pattern on the applicability of each structure is evaluated comparing these results to a previous research for a grid city. Three basic structures are analyzed: a radial scheme, a direct-trip-based network, and a hybrid structure as a transfer-based alternative. Each structure is dominant for a specific range of dispersion: radial networks for scenarios of high concentration, direct-trip-based systems for intermediate degrees of dispersion, and transfer-based structures when the activities are decentralized. However, constraints on stop capacity modify these ranges. Each structure presents a different distribution of travel time in the transit chain and agency costs that determine the most competitive alternative. In addition, the behavior of the structures and the evolution of costs regarding urban decentralization are practically the same for both street patterns: system costs grow with increasing mobility dispersion, the range of applicability for each structure is the same, and changes in their applicability when main input parameters vary are very similar. Therefore, these results make it possible to generalize about the conclusions obtained independently of the street layout.

Recent studies through simulation and empirical data have shown that a Network Macroscopic Fundamental Diagram (NMFD or MFD) exists for multi-modal urban networks. However, more investigation should be conducted to explore the properties of multi-modal NMFD. In particular, the effects of operational characteristics of public transit like the number of lines, bus stop type, and bus stop location on multi-modal NMFD needs to be discussed. This paper discusses the effects of the near-side bus stop (those located before the intersection) and far-side bus stop (i.e. located after the intersection) on the NMFD of a bi-modal urban network in which cars and buses share the same space, i.e. there is no dedicated lane for buses. Results show that the NMFD in case of having far-side bus stops leads to a bigger range of critical density (density corresponded to maximum flow) for the car, while network capacity is almost the same. This results in a bigger optimal operational regime. Our findings, which are consistent with previous studies, yield that the far-side bus stop is superior to the near-side bus stop from the network operation perspective.

We analyze the efficiency of semi-autonomous platooning vehicles as an alternative to conventional vehicles in bus and BRT (bus rapid transit) systems. For each service type, optimal bus size, service headway and platoon length are obtained by minimizing total generalized cost, which includes passengers’ and the service provider’s costs. Results show that as the demand level increases, semi-autonomous vehicles can be introduced to enable a better service in both traditional bus and BRT systems. The benefits of semi-autonomous buses become more significant as the capacity upper bound decreases.

EWGT 2018, Euroworking Group on Transportation, Braunschweig, ALLEMAGNE, 17-/09/2018 - 18/09/2018; The paper develops a structural model and a design methodology for transit system planning in an urban area. Transit "components" are modelled by subarea and by sub-mode in terms of line length, station spacing, and fleet size, in order to determine both quality of service and production costs. Roadway networks are modeled with a Macroscopic Fundamental Diagram that relates speed to network capacity and vehicle demand. Local and global environmental impacts are considered. Travel demand includes both mode-dependent users and mode-choosers able to adopt the mode that offers higher utility. The design methodology involves a mathematical program of welfare optimization with respect to transit factors and fares. Two definitions of welfare are given, one that takes into account only demand surplus and supply profit, the other including environmental impacts. An example of application to Greater Paris shows that there is room for system optimization under current subsidy conditions, and that the explicit inclusion of environmental impacts brings about a significant shift in the "optimal" policy package.

Conventional wisdom states that transit riders are averse to transfers and that consequently bus networks should be designed to limit their number. Probably as a result of this belief, many real bus systems try to connect as many origins and destinations as possible without transfers, so they are usually composed of long, circuitous routes with redundant overlapping sections – and the resulting bus map is hard to understand. If coverage is extensive, many routes are needed. Economics then prevents an agency from populating all routes with sufficient buses to provide attractively frequent service. This low frequency and the complicated circuitous map discourage transfers, perpetuating the belief that people are averse to transferring. Not surprisingly, the percentage of bus trips that includes a transfer has been reported to be: 1.5% for Boston, 3% for New York, 13% for London, and 16% for Melbourne. The Nova Xarxa in Barcelona was designed with a different paradigm. It was designed and deployed to cover the whole city on the belief that if a bus map is easy to understand, and has direct lines with frequent service and ubiquitous transfer points then the bus system would become more appealing, people would transfer more freely and become users of the network rather than its single lines. With this design paradigm, a city can be covered with fewer lines, which can be depicted on a simple map. The lines can in turn be economically populated with sufficient buses to deliver the high frequency required to encourage transfers. Could this work? To answer this question and see whether there is truth in the beliefs underlying the new paradigm, this paper examines data from the first three deployment phases of the Nova Xarxa (from 2012 to 2015). It is found that the Nova Xarxa is already attracting more demand than the network it replaced. This attests to its appeal. Furthermore, this demand has increased disproportionately with the number of lines opened for service in each phase, revealing that some people are using the Nova Xarxa as a network. The paper further shows that this growth is underpinned by transfers -- at the end of 2015, the percentage of trips that involved a transfer was approximately 26%, and it reached a maximum of 57% for line V7. These numbers should increase considerably (to 44% and 66%, respectively) once the Nova Xarxa is completed in 2018 and passengers have even more opportunities for transferring. The numbers disprove the conventional wisdom. They strongly suggest that transit providers can attract more demand by providing transfer-friendly networks that can be used as such and not as an inefficient aggregation of individual lines.

This paper presents a reformulation of the hybrid model developed by Daganzo (2010) to extend its applicability to a greater number of cities, especially those characterized by a radial street pattern. The new transit network structure is also composed of two types of schemes: radial/circular in the central area and hub and spoke in the periphery. This analytical model defines the optimal network layout through minimizing its objective function, which is composed of agency and user costs. Its decision variables are central area size, headway, line spacing, and stop spacing. In this reformulation, stops with single coverage, those only served by one line, are introduced in the hybrid model to improve spatial accessibility to avoid an increase in agency investment. This model is a tool to design competitive transit systems topologically characterized by simple schemes adapted to the urban structure and concentrated transit flows, and also operatively by high frequencies and speeds. Ultimately, all this allows for easy use and management of transit networks. The model’s robustness with regard to input parameters and decision variables reinforces its results and estimates what implementations on real road networks would be like. It presents coherent behavior regarding real-world standards, where high, concentrated and temporally well distributed demands lead to more efficient and effective transit systems. High performance bus (HPB) is the transport technology used throughout this paper because, as has been proved in this paper, it is the best transit mode in urban areas for a wide range of demand values. Main system characteristics have been obtained such as central areas greater than a 25% of the city, low headways of around 2 min, high commercial speeds ranges between 14 and 17 km/h, and suitable spatial accessibility, where stop spacing moves between 350 and 550 m.

This paper presents and tests a method to design high-performance transit networks. The method produces conceptual plans for geometric idealizations of a particular city that are later adapted to the real conditions. These conceptual plans are generalizations of the hybrid network concept proposed in Daganzo (2010) . The best plan for a specific application is chosen via optimization. The objective function is composed of analytic formulae for a concept’s agency cost and user level of service. These formulae include as parameters key demand-side attributes of the city, assumed to be rectangular, and supply-side attributes of the transit technology. They also include as decision variables the system’s line and stop spacings, the degree to which it focuses passenger trips on the city center, and the service headway. These decision variables are sufficient to define an idealized geometric layout of the system and an operating plan. This layout-operating plan is then used as a design target when developing the real, detailed master plan. Ultimately, the latter is simulated to obtain more accurate cost and level of service estimates. This process has been applied to design a high performance bus (HPB) network for Barcelona (Spain). The idealized solution for Barcelona includes 182 km of one-way infrastructure, uses 250 vehicles and costs 42,489 €/h to build and run. These figures only amount to about one third of the agency resources and cost currently used to provide bus service. A detailed design that resembles this target and conforms to the peculiarities of the city is also presented and simulated. The agency cost and user level of service metrics of the simulated system differ from those of the idealized model by less than 10%. Although the designed and simulated HPB systems provide sub-optimal spatial coverage because Barcelona lacks suitable streets, the level of service is good. Simulations suggest that if the proposed system was implemented side-by-side with the current one, it would capture most of the demand.

This study discusses which transit network structure is the best option to serve urban mobility. As a consequence of the evolution of urban form, cities have undergone a process of dispersion of their activities that has caused a change in mobility needs in the last few decades. Mobility networks and services should progressively adapt to the new demand patterns, especially the bus transit network, which has more flexibility to absorb the changes. We compare four base transit network structures: a radial scheme, a direct trip-based network, and a transfer-based system by means of either a complete grid or a hybrid structure. An analytical model is used to estimate the behavior of these structures for idealized monocentric mobility patterns with several degrees of concentration. The purpose is to determine the right range of situations for the applicability of each bus transit structure, and to determine guidelines about the transit network planning process. It turns out that the best structure is not always the same, and depends on the mobility spatial pattern. A radial network is the best alternative in very concentrated cities; however, a direct trip-based system is more suitable for intermediate degrees of dispersion. A transfer-based structure is the best option when the activities are more decentralized. Nevertheless, the decentralization degree that justifies a specific transit structure is not constant. This degree depends on the characteristics of the city, transport technology and users.