Borja Alonso

Bus Stop Location under Different Levels of Network Congestion and Elastic Demand

Abstract The article analyses optimal bus stop locations under different network congestion levels applying a bi-level optimisation model, covering an upper level minimizing an overall cost function (Social Cost) and a lower level that includes a modal split assignment model. This model is applied to Santander city (Spain) under a range of demand levels, starting from very low to high congestion, representing the evolution of variables in each case and analysing different solutions. The optimal distances between stops obtained for each demand and congestion level indicate that very low demands produce wider spaces. However, as demand increases, accessibility to public transport service should be increased and then spacing between bus stops drops to 360 metres.

Modeling the Service Quality of Public Bicycle Schemes Considering User Heterogeneity

This article proposes a methodology for studying the quality of service perceived by users of a public bicycle scheme. The public is involved from the first phases of the research through their presence in focus groups to identify the relevant variables asked about in the survey. Ordered probit models have been calibrated that consider systematic variations in preference and random parameters. The results highlight the importance of safety and available information above other service variables, as well as the adjustment in perception of overall quality after considering each of the characteristics of the service, as it is proposed in this methodology.

Public Transport Line Assignment Model to Dual-Berth Bus Stops

Bunching at bus stops can be a major problem for traffic and passengers if bus arrivals are not well distributed. Arrivals can be better staggered if bus stops are divided into more than one berth. This article presents a methodology using a bilevel optimization model for assigning public transport routes to bus stops that have been divided to increase their capacity. The upper level minimizes the user costs, and the lower level applies a public transport assignment model under congestion conditions. The model is first applied to an example network to compare different assignment configurations; it is then applied to a real case in the city of Santander, Spain. The quantified benefits of an optimal route-stop assignment show increases of 10% in average bus speed and reductions of 5% in user costs.

A simulation tool for bicycle sharing systems in multimodal networks

This paper presents a methodology for modelling an urban transport system, integrating public bicycles in a multi-modal network. A bike cost function that reproduces the effect of slopes on cycling speeds is proposed. Also, the effect of traffic levels on the attractiveness of cycling routes is taken into account. The model applies the modal split and network assignment phases in a multimodal network with different classes of users. It has been verified over a test network and then validated by applying it to a real case in the city of Santander in Spain. The results obtained make this model a useful decision-making tool to encourage the use of the public bicycle from a sustainable development point of view.

Analytical model for calibrating delay at congested bus stops

Abstract A model is proposed to calculate the overall operating and delay times spent at bus stops due to passenger boarding and alighting and the time lost to queuing caused by bus stop saturation. A formula for line demand at each stop and the interaction between the buses themselves is proposed and applied to different bus stops depending on the number of available berths. The application of this model has quantified significant operational delays suffered by users and operator due to consecutive bus arrival at stops, even with flows below bus stop capacity.

Using O–D matrices for decision making in road network management

Abstract This article uses a real example to demonstrate the importance of mobility modelling (objective criteria) on correctly planned investments in infrastructure. Some radical conclusions are drawn which differ greatly from those suggested by more subjective mental models. Strategic developments on inter-urban networks are evaluated by applying a mobility model including a model for estimating O–D matrices based on traffic counts and a model for the optimal location of traffic counting stations at the same time as a population accessibility model. An important decision making tool is provided for planning investments in road infrastructure by rationalising the high public spending required for this type of work. The models are applied to various possible projects at determined points on a regional road network in the Autonomous Community of Cantabria (Northern Spain) following the proposals and demands of different social and political groups. The models find a 68% reduction in the number of links req...

An Environmental Approach to Optimize Urban Freight Transport Systems

This chapter proposes an optimization-simulation model for planning and managing an urban freight transport system, which has to serve one or more points of the network that receive and/or generate a great volume of cargo, using trucks. This type of transport has special characteristics and generates significant impacts: increased traffic congestion, due to the presence of large vehicles which take up much space and are very slow; and air pollution caused by the extra traffic volume and the extra congestion. Therefore, the purpose of the model is to minimize these negative effects on the environment and on the users of the local road network. To achieve this goal, the authors propose and solve an optimization problem to minimize the total system cost (operating costs of the suppliers, costs supported by private vehicle users and public transport users, operating costs of the public transport, etc.). The proposed optimization problem is a bi-level mathematical programming model, where the upper level defines the total cost of the system, and the lower level defines the behaviour of private and public users, assuming that each of them chooses the route that minimizes his total journey cost. Then, this model is applied to the real case in the city of Santander (Northern Spain) obtaining a series of interesting conclusions from the corresponding sensitivity analysis.

Bus Size and Headways Optimization Model Considering Elastic Demand

This article proposes an optimization model for designing the intervals (headways) and sizes of buses circulating on public transport networks by minimizing the system’s operating and user costs. The proposed model takes into account congestion on the public transport system and works by considering elastic demand, allowing the analysis of the repercussions of modifications made to the operational characteristics of the public transport system on changes in users’ mode of transport. An in-depth sensitivity analysis checks the influence the value of time has on the final model results, and these results are compared with those from a model using inelastic demand. The validity of the proposed model is shown by applying it to the city of Santander, Spain. Finally, the consideration of elastic demand is shown to be beneficial in response to proposed operational changes rather than the assumption of a fixed and known public transport trip matrix.