Studying the benefits of carpooling in an urban area using automatic vehicle identification data

Carpooling has been considered a solution for alleviating traffic congestion and reducing air pollution in cities. However, the quantification of the benefits of large-scale carpooling in urban areas remains a challenge due to insufficient travel trajectory data. In this study, a trajectory reconstruction method is proposed to capture vehicle trajectories based on citywide license plate recognition (LPR) data. Then, the prospects of large-scale carpooling in an urban area under two scenarios, namely, all vehicle travel demands under real-time carpooling condition and commuter vehicle travel demands under long-term carpooling condition, are evaluated by solving an integer programming model based on an updated longest common subsequence (LCS) algorithm. A maximum weight non-bipartite matching algorithm is introduced to find the optimal solution for the proposed model. Finally, road network trip volume reduction and travel speed improvement are estimated to measure the traffic benefits attributed to carpooling. This study is applied to a dataset that contains millions of LPR data recorded in Langfang, China for 1 week. Results demonstrate that under the real-time carpooling condition, the total trip volumes for different carpooling comfort levels decrease by 32–49%, and the peak-hour travel speeds on most road segments increase by 5–40%. The long-term carpooling relationship among commuter vehicles can reduce commuter trips by an average of 30% and 24% in the morning and evening peak hours, respectively, during workdays. This study shows the application potential and promotes the development of this vehicle travel mode.     

Estimating the demand for urban bus travel

The disadvantages of conventional transportation study models, in particular their large data requirements and their weaknesses in dealing with changes in trip generation rates have led to a need for a simple model that can quickly and at low cost examine alternative public transport strategies.This paper investigates simple economic models of bus demand, examines alternative variables that can be used and discusses some alternative model forms. It demonstrates the results of a model using data from twelve urban bus operators in Britain and compares the results with those from other types of study. The model utilises fare and service quality elasticities to explain the decline in passengers on urban bus services, and derives an average elasticity with respect to fare changes of –0.31 and with respect to service quality changes of +0.62. It is estimated that fare rises accounted for 13% of the 43% decline in passengers over the last fifteen years, vehicle mileage reductions for 14.3% and that only 15.7% was due to such factors as rising car ownership which are often given as the cause of declining bus patronage.The results, by showing that passengers are far more sensitive to changes in service than they are to fare rises, are a useful guide to the broader public transport policy issues, and the paper concludes that the model does provide a useful method of forecasting public transport demand at a strategic level. Further work is needed, however, to establish more accurate forecasts for different types of passenger and studies are now being undertaken to establish these and to construct an operational forecasting model that can be applied with only limited data requirements     

Some thoughts on competitive tendering in local bus operations

Abstract

This article is derived from a report by Metra Consulting Group for the Dutch Ministry of Public Health and the Environment. The aim of Metra's study was to identify ways of reducing the environmental nuisance of urban traffic without adding excessively to transport costs.

The main theme of the article is that the traditional idea of an inherent conflict between transport efficiency and the environment is mistaken. Both efficiency and the environment are threatened by the same thing: the excessive and indiscriminate use of vehicles. This comes about because of defects in the fiscal and regulatory framework within which people take transport decisions. Suitable reforms in this framework would simultaneously enhance the environment and improve access for all classes of road user.

In the development of this theme, particular attention is paid to transport activities which tend to be neglected by policy makers, such as walking, cycling and urban goods distribution; and to measures which are not always thought of as instruments of policy at all, such as locational policy and development control, vehicle design, and vehicle taxation, especially of goods vehicles.     

Integrated optimization of bus priority operations in connected vehicle environment

Most previous works associated with transit signal priority merely focus on the optimization of signal timings, ignoring both bus speed and dwell time at bus stops. This paper presents a novel approach to optimize the holding time at bus stops, signal timings, and bus speed to provide priority to buses at isolated intersections. The objective of the proposed model is to minimize the weighted average vehicle delays of the intersection, which includes both bus delay and impact on nearby intersection traffic, ensuring that buses clear these intersections without being stopped by a red light. A set of formulations are developed to explicitly capture the interaction between bus speed, bus holding time, and transit priority signal timings. Experimental analysis is used to show that the proposed model has minimal negative impacts on general traffic and outperforms the no priority, signal priority only, and signal priority with holding control strategies (no bus speed adjustment) in terms of reducing average bus delays and stops. A sensitivity analysis further demonstrates the potential of the proposed approach to be applied to bus priority control systems in real‐time under different traffic demands, bus stop locations, and maximum speed limits. Copyright © 2016 John Wiley & Sons, Ltd.     

Cost benefit analysis of three different urban bus drive systems using real driving data

One of the CIVITAS-ELAN project measures in Ljubljana, Slovenia, was the introduction of alternative city bus propulsion systems (CNG, hydraulic hybrid buses) into the public transport and comparison of their performance in terms of costs and benefits with conventional (diesel) buses. A cost-benefit analysis was conducted to provide a model for identifying the most attractive alternative, with aim of aiding the decision making process for future rational up-scaling of the alternative propulsion technologies in PT fleet in Ljubljana. This paper focuses on presenting the key findings of this CBA, using real driving data, while demonstrating the sensitivity/variance of different parameters of a CBA, as well as the differentiation between uncertainties of parameters in an ex-ante analysis versus an ex-post analysis.     

A cost-competitiveness analysis of charging infrastructure for electric bus operations

This study investigates the cost competitiveness of different types of charging infrastructure, including charging stations, charging lanes (via charging-while-driving technologies) and battery swapping stations, in support of an electric public transit system. To this end, we first establish mathematical models to investigate the optimal deployment of various charging facilities along the transit line and determine the optimal size of the electric bus fleet, as well as their batteries, to minimize total infrastructure and fleet costs while guaranteeing service frequency and satisfying the charging needs of the transit system. We then conduct an empirical analysis utilizing available real-world data. The results suggest that: (1) the service frequency, circulation length, and operating speed of a transit system may have a great impact on the cost competitiveness of different charging infrastructure; (2) charging lanes enabled by currently available inductive wireless charging technology are cost competitive for most of the existing bus rapid transit corridors; (3) swapping stations can yield a lower total cost than charging lanes and charging stations for transit systems with high operating speed and low service frequency; (4) charging stations are cost competitive only for transit systems with very low service frequency and short circulation; and (5) the key to making charging lanes more competitive for transit systems with low service frequency and high operating speed is to reduce their unit-length construction cost or enhance their charging power.     

A fuzzy multicriteria model to evaluate the privatization of the public bus operations

A double model based on fuzzy synthetic decision and a fuzzy multicriteria decision is presented for this study. In a basic level decision, we use a fuzzy synthetic decision to reduce the sub-criteria calculation work. In a higher level decision, the approximation reasoning allows the decision maker to make his best choice. These methods are more in accordance with the thinking processes of the human mind when complex issues are involved. Therefore, this paper will use a fuzzy linguistic approach, instead of the traditional approach to avoid the interference of the numerical estimates for weight and performance of alternatives. In the end, a heuristic algorithm for the evaluating process is developed and demonstrated in a case study.     

Are urban bus services natural monopolies?

Although Britain's local bus services have been open to free competition for more than three years, most have continued to be operated as monopolies by the original incumbents. Some competition has occurred, but the incumbents have usually driven off entrants. This paper uses findings from case-studies of competition and from deregulation generally to consider whether monopoly operation has inherent advantages over competitive operation. If so, urban bus routes would be natural monopolies. The evidence suggests that they may be, because single-operator services are more convenient for users.     

An assessment of the benefits of the walking school bus in Christchurch,New Zealand

A Walking School Bus involves parents or other adults escorting a group of children on a set route to school. The first one was established in 1996 in Canada. They can now be found in a variety of countries, including New Zealand. Many of the benefits associated with them are based on the general benefits of affecting a modal shift away from cars in favour of walking. However, there is still relatively little known about the less quantifiable benefits of them, and there has been some suggestion that they can adversely affect children’s independent mobility. This research examined the perceived benefits of Walking School Buses by interviewing people involved in the day to running of the scheme in Christchurch, New Zealand. The results suggest that walking school buses have many social benefits and that if anything; they encourage children’s independent mobility.     

Analysis and simulation of an urban bus route

A highly developed and flexible simulation model of an urban bus route in peak hour traffic is described. The simulation program is presented, with particular emphasis on the facilities for interactive control of the simulation run and for presentation of overall and detailed statistics from the simulation. An independent statistical program system, based on the mathematical models underlying the simulation model, has been used to provide input parameters for the simulation. This program is applied to the analysis of a bus route in central Stockholm; in this connection the mathematical models are discussed.     

Productive efficiency and ownership of urban bus services

The established ownership mix of urban bus operations in Australia provides a unique opportunity to investigate the productivity differences between public and private bus service supply. Using duality theory in economics which links economic indices of factor productivity to the cost structure of a firm, we develop empirical measures of total and partial productivity of inputs, and adjust the differences for the effects of ownership status and operating environment. The evidence supports the notion that private supply of public passenger transport in general has performed more efficiently in the past than public supply, although the differences in productivity need not continue in the future.     

A model of stoppings on urban bus routes

The amount of time required to pick up and discharge passengers is an important issue in the planning and modeling of urban bus systems. Several past studies have employed models of this component of bus travel time which are based, in part, on a model of the number of stoppings the bus makes to pick up or discharge passengers. Most past versions of this model have assumed that expected demand does not vary from stop to stop or from trip to trip, but that the number of passengers demanding service at any given stop during any given trip follows a Poisson distribution. An alternative model is derived, based on the assumption that expected demand varies among stops and times of day but is fixed from day to day at any given stop and time of day. Boarding and alighting survey data are used to verify that the “average-demand” Poisson model consistently overestimates the number of stoppings and to calibrate an approximate version of the alternative model. A stop-spacing optimization model previously developed by Kikuchi and Vuchic is reevaluated using the alternative stopping model in place of the average demand model used in the original version. The results are found to be considerably different, thus indicating that transit route optimization models are sensitive to the way in which stopping processes are modeled.     

Cost benefit analysis of urban minibus operations

Earlier work by the Transport Studies Group of the Polytechnic of Central London on minibus development in Britain for the Transport and Road Research Laboratory provided a financial analysis of intensive urban minibus operation. This is taken as the basis for the application of cost-benefit analysis. Unit operating cost savings and passenger benefits are taken into account, using typical demand elasticities derived from earlier work. Particular attention is paid to the problem of evaluating passenger benefits for which waiting time at the roadside is not necessarily an adequate proxy. A direct survey of passenger waiting times indicates that these do not necessarily decrease when a higher-frequency minibus service replaces a conventional bus service but the improved convenience produces an increase in ridership which may be assessed in terms of a demand curve shift to estimate benefits obtained.     

The effects of non-contingent free bus tickets and personal commitment on urban bus ridership

To compare the effects of free rides and commitment to a performance goal on increasing bus ridership in an urban setting, 83 non-bus riding automobile drivers were exposed to one of the following conditions. (1) Control where route and schedule information were provided. (2) Commitment, where subjects agreed to ride the bus twice a week during the treatment period. (3) Free Tickets, where an unlimited supply of free bus tickets were provided. (4) Free Tickets Plus Commitment, where the free transit and commitment conditions were combined. While there were no systematic differences between the experimental conditions, each of them produced significantly higher levels of ridership than the no-treatment control group during the 4 week treatment period and two subsequent follow-up periods. These results suggest that both free rides and agreement to a specific performance goal can overcome many of the obstacles which prevent individuals from initiating and maintaining regular patterns of bus ridership.     

The development of urban bus regulatory policy in Korea reviewed

The urban bus industry in Korea used to be controlled to provide stable transport services and enable operators to secure proper profits, but there were adverse effects within the industry such as inadequate business management and a downward spiral of low quality services resulting from lower fares. The government began easing restrictions on entry, operation, fares, and some conditions and procedures for licensing in the late 1980s, until in 1993, the government published a package of deregulatory measures that were considerably more drastic than those previously seen, such as freely adjusting the number of vehicles within 10%, easing the restrictions and requirements for operators’ employing staff and drivers, and improving the fare system. However, these measures seem to have been introduced too late and too luke‐warmly to encourage new entrants to the industry. Therefore, to gain the desirable effects of deregulation and to secure the development of the urban bus sector, there needs to be provision of a market atmosphere and greater scope for free competition; a positive attitude among operators for efficient business management and new services; and alert observation and monitoring by passengers.     

Modeling schedule recovery processes in transit operations for bus arrival time prediction

Many existing algorithms for bus arrival time prediction assume that buses travel at free‐flow speed in the absence of congestion. As a result, delay incurred at one stop would propagate to downstream stops at the same magnitude. In reality, skilled bus operators often constantly adjust their speeds to keep their bus on schedule. This paper formulates a Markov chain model for bus arrival time prediction that explicitly captures the behavior of bus operators in actively pursuing schedule recovery. The model exhibits some desirable properties in capturing the schedule recovery process. It guarantees provision of the schedule information if the probability of recovering from the current schedule deviation is sufficiently high. The proposed model can be embedded into a transit arrival time estimation model for transit information systems that use both real‐time and schedule information. It also has the potential to be used as a decision support tool to determine when dynamic or static information should be used.     

Reforming the urban public transport bus system in Malta: Approach and acceptance

The islands of Malta have joined the European Union in 2004 and have for the past decade suffered a decline in the patronage of its public transport service. Offered under a monopoly by an Association of individual owner drivers, the public transport service has not changed dramatically since its start in the early 1900s. Instead, an organic growth alongside the main routes linking new areas to the public transport network and a declining level of service pushed even more the local population to switch to private mobility. This has classified the islands amongst the countries in the world with the highest levels of motorisation. In 2008, following a general election and a general strike held by the public transport operators over the Government’s intentions to remove monopolies, the new Minister for Transport published his intentions to reform public transport from its roots. This reform included the removal of the monopolies protecting the incumbents as well as developing a new network of services which cater more effectively to the public’s travelling demands. This paper deals with the public transport reform and through direct observation details the processes involved in the regulation of public transport as well as the design of the new public transport network. The paper concludes with the critical factors which led to implementation of the reform and how this is applicable to cities worldwide.