Peak-Load Pricing of a Bottleneck with Traffic Jam

This paper generalizes the model of bottleneck congestion such that formation and development of traffic jams is explicitly formulated. The model is applied to the peak-load problem for the morning rush hour: every morning, a fixed number of commuters travel across a roadway, and each of them chooses departure time to minimize commuting cost consisting of travel time cost, scheduling cost, and toll. Equilibrium and optimal patterns of departure are solved and optimal peak-load toll is derived. Incorporating traffic jams alters the earlier results in the literature. That is, road users may be better off from paying the optimal peak-load toll. Conditions under which such a result is obtained are identified by simulations.     

Road congestion: A reconsideration of pricing theory

In this paper, the effect of congestion tolls upon the pattern of traffic flows is examined. Congestion tolls influence the individual commuter's decision of when to make a trip, inducing him to travel at less congested times. When all commuters are taken together, congestion tolls and the individual consumers' decisions lead to an efficient reorganization of traffic flows relative to a non-toll situation. In fact, for the same total number of commuters, per person costs of travel including the toll may decline with the imposition of tolls and efficient reorganization of traffic flows.     

Travel time and transportation policy

This paper examines the relationship between traffic congestion and travel time. A model is developed where both travel time and the number of peak-hour trips are simultaneously determined. The model is estimated by two-stage least squares using traffic data from the Boston metropolitan area. The estimates are used to generate implications for transportation policy. The paper suggests that commuters are substantially more responsive to changes in travel time than to changes in price.     

公交实时信息化服务对乘客出行行为意向影响

为了解城市公交信息化服务对公交乘客出行方式转移的影响,以上海市杨浦区为例,进行关于公交信息化服务下乘客出行方式转移的调查,获取个人属性、公交出行经历、公交出行评价、出行方式转移意向以及公交信息服务需求等信息。从公交信息使用者角度,重点关注公交信息化服务对乘客出行方式转移的影响,分别构建信息化服务情境下(公交到站时间与计划出发时间相差过大和车辆未在提示的时间内到达)的公交出行方式转移二项logit模型。模型结果表明:乘客平均候车时间、是否经常使用公交到站服务、是否有道路拥挤车辆未按时进站等原因而产生出行延误的经历、公交信息准确性评价与是否有必要提示同公交线路连续班次的到站时间等因素对不同情景下的乘客出行方式转移具有显著影响。     

Understanding peak avoidance commuting by subway: an empirical study in Beijing

Congestion is a major problem for peak-hour commuters in the Beijing subway system, as it leads to long queuing times and overcrowded vehicles. This paper explores to what extent peak travel can be reduced by providing incentives for peak avoidance. In a stated preference study, travellers’ responses to two financial and two non-financial incentives were measured, and factors increasing or limiting the response were identified. Our results suggest that all four incentives can be reasonably effective tools and the financial incentives seem to have a slightly stronger effect than the services and credit-for-gifts-based scenarios. Ordered logit models indicate that various factors influence people’s receptiveness of incentives for peak avoidance which relate to the ease of change or presence of alternatives and receptiveness to incentives. Both theoretical and policy implications are concluded that the proposed factors and incentive system can help solving the subway congestion in Beijing.     

Does public transit reduce car travel externalities? Quasi-natural experiments' evidence from transit strikes

One of the unanswered questions in the field of urban economics is to which extent subsidies to public transit are justified. We examine one of the main benefits of public transit, a reduction in car congestion externalities, the so-called congestion relief benefit, using quasi-natural experimental data on citywide public transit strikes for Rotterdam, a city with mild congestion levels. On weekdays, a strike induces travel times to increase only marginally on the highway ring road (0.017 min/km) but substantially on inner city roads (0.224 min/km). During rush hour, the strike effect is much more pronounced. The congestion relief benefit of public transit is substantial, equivalent to about 80% of the public transit subsidy. We demonstrate that during weekends, travel time does not change noticeably due to strikes. Furthermore, we show that public transit strikes induce similar increases in number of cyclists as number of car travelers suggesting that bicycling-promoting policies to reduce car congestion externalities might be attractive in combination with first-best congestion pricing.     

Timing Equilibria in an Urban Model with Congestion

All spatial urban models with congestion assume that the departure (arrival) time of commutes is exogenously determined and assume that travel speed at a given time and location depends upon the traffic density at that point in time and space. This paper presents a framework that encompasses such models, but allows workers to choose the time at which they leave home (arrive at work). This paper then proves that in general only one equilibrium exists for urban models with traditional congestion technology: a commuting pattern in which commuting is continuous and the rush hour never ends, which is unrepresentative of traffic patterns anywhere. This paper concludes by discussing alternative general equilibrium urban models with congestion that may have more realistic equilibria.     

Trip-timing decisions with traffic incidents

This paper analyzes traffic bottleneck congestion when drivers randomly cause incidents that temporarily block the bottleneck. Drivers have general scheduling preferences for time spent at home and at work. They independently choose morning departure times from home to maximize expected utility without knowing whether an incident has occurred. The resulting departure time pattern may be compressed or dispersed according to whether or not the bottleneck is fully utilized throughout the departure period on days without incidents. For both the user equilibrium (UE) and the social optimum (SO) the departure pattern changes from compressed to dispersed when the probability of an incident becomes sufficiently high. The SO can be decentralized with a time-varying toll, but drivers are likely to be strictly worse off than in the UE unless they benefit from the toll revenues in some way. A numerical example is presented for illustration. Finally, the model is extended to encompass minor incidents in which the bottleneck retains some capacity during an incident.     

Optimal density of radial major roads in a two-dimensional monocentric city with endogenous residential distribution and housing prices

This paper proposes an analytical urban system equilibrium model for optimizing the density of radial major roads in a two-dimensional monocentric city. The proposed model involves four types of agents: local authorities, property developers, households and household workers (i.e. commuters). The local authorities aim to maximize the total social welfare of the urban system by determining the optimal density of radial major roads in the city. The property developers seek to determine the intensity of their capital investment in the land market to maximize the net profit generated from the housing supply. The households choose residential locations that maximize their utility within a budget constraint, and the commuters choose the radial major roads that minimize their individual costs of travel between home and workplace. A heuristic solution procedure is developed to find the urban system equilibrium solution. A system optimum model is also proposed to optimize the density of radial major roads that maximizes the social welfare of the urban system. The proposed model can endogenously determine household residential distribution and land values across the city, along with the housing market structure in terms of housing prices and space. Numerical comparative static analyses of congestion pricing and road infrastructure investment (adding a new radial major road) are carried out together with evaluation of the effects of the service level of radial major roads, urban population size, and household income level on the urban economy.     

居民出行信息服务水平评估方法——以昆明市为例

良好的出行信息服务能够便于出行者制定出行计划,减少其出行过程中的时空消耗。为了科学评价居民出行信息服务水平并提出合理的优化对策,从出行者角度对居民出行信息服务水平进行了详细的分析,将出行信息服务分为出行前信息服务、静态出行信息服务和动态出行信息服务三大类。依据出行行为特征建立出行信息服务水平评价指标,通过居民出行信息服务调查来采集实际数据,并利用AHP法确定指标权重,通过模糊综合评价对昆明市居民的出行信息服务水平进行了评估。评价结果表明昆明市的出行信息服务水平较差,并基于评价结果提出了具体的优化措施。     

Insights into the effect of traffic congestion on distribution network characteristics – a numerical analysis based on navigation service data

This research studies effects that the average increase in travel times due to road traffic congestion has on characteristics of an existing distribution network. It presents the most detailed estimate of ‘on-the-road’ effects on distribution network characteristics up to now, from the network modelling perspective and from the processed data point of view. A concrete network model allowing for the representation of all relevant transportation flows is presented. The processed traffic information relies on navigation service data. The use of such data allows the requirements that arise for the traffic analysis of a whole distribution network to be met. It is shown that this data source may considerably contribute in forthcoming research. The effects of traffic congestion are quantified to get insights into the extent to which regular traffic congestion affects distribution network characteristics and to understand the mitigating effect when the number of distribution centres is increased.     

Parcel distribution timetabling problem

In this paper we propose a model to generate an effective timetable for time definite parcel distribution companies operating a hierarchical hub-and-spoke network. The model, referred to as parcel distribution timetabling problem, provides the departure times from each serviced city and each servicing facility in order to minimize the travel times of all shipments from their origin cities to their destination cities. Although the problem is faced by every parcel distribution company, it is rarely addressed in the literature. There is no evidence that parcel distribution companies, including the international ones, are developing operational research models in generating their timetables. The application of the model to a real-world case led to a decrease of more than 11% in the average travel time of the shipments. The company was even more delighted by the rapidity of the model in generating the timetable; this task that used to take weeks is decreased to just minutes.     

斯德哥尔摩内城交通拥挤收费政策述评

在回顾斯德哥尔摩内城地区"交通拥挤收费"政策出台背景的基础上,从收费时间、收费区域、收费标准、收费对象、付费方式等方面,概括了其交通拥挤收费政策的主要内容;从交通流量、出行时间、出行方式等方面分析了交通拥挤收费政策的治理效果;对斯德哥尔摩"交通拥挤收费"政策的探索历程进行了政策评判。认为拥挤收费政策带有强烈的政治色彩,是政党联盟与政治妥协的产物;拥挤收费政策是一套囊括诸多措施、相互间配合严密的一揽子方案;拥挤收费政策采取了政府引导、公众参与的审慎推进策略;拥挤收费政策构建了科学的信息沟通、反馈机制以及决策支持系统;拥挤收费政策虽取得较好的效果,但仍然可能存在一系列负面效应;拥挤收费政策的运行主体多元,相互间展开了有序分工与密切协作。     

Stochastic Route Choice Equilibrium Assignment for Travelers with Heterogeneous Regret Aversions

Most route choice models assume that people are completely rational. Recently, regret theory has attracted researchers’ attentions because of its power to depict real travel behavior. This paper proposes a multiclass stochastic user equilibrium assignment model by using regret theory. All users are differentiated by their own regret aversion. The route travel disutility for users of each class is defined as a linear combination of the travel time and anticipated regret. The proposed model is formulated as a variational inequality problem and solved by using the self-regulated averaging method. The numerical results show that users’ regret aversion indeed influences their route choice behavior and that users with high regret aversion are more inclined to change route choice when the traffic congestion degree varies.     

(When) Do hub airlines internalize their self-imposed congestion delays?

Specification tests using stochastic bottleneck models of airport congestion investigate whether dominant airlines internalize or ignore self-imposed delays at twenty-seven major US airports. Data on flight times determine the airport's landing and takeoff delays for every minute of operation during peak travel days. Dynamic congestion functions based on stochastic-queuing theory separately identify delays that aircraft experience directly, impose internally on their airline's other aircraft, or impose externally on other airlines. Specification tests largely reject internalization and fail to reject non-internalization by dominant airlines. Optimal pricing should value all time using non-dominant aircraft time values and treat all delays as external.     

Optimal highway design and user welfare under value pricing

This paper investigates the optimal design of highways operated under a form of congestion pricing called value pricing. Value pricing involves dividing a highway into free and priced lanes so that in equilibrium the highway effectively operates at two levels of service, with those users placing a higher value on travel time savings selecting the faster, priced route. A tractable analytical framework is developed which allows analysis of equilibrium and welfare on value priced highways when users vary in their value of time. The model is used to characterize optimal toll and capacity policies, as well as investigate the fiscal implications of value pricing. The analysis concludes with results on how welfare changes induced by value pricing are distributed over the population of users when the government finances any funding shortfall through a non-discriminatory taxing mechanism. A realistic numeric example is used to illustrate how the model can be applied to evaluation of actual and proposed value pricing implementations.     

Congestion in a city with a central bottleneck

We consider dynamic congestion in an urban setting where trip origins are spatially distributed. All travelers must pass through a downtown bottleneck in order to reach their destination in the CBD. Each traveler chooses departure time to maximize general concave scheduling utility. We find that, at equilibrium, travelers sort according to their distance to the destination; the queue is always unimodal regardless of the spatial distribution of trip origins. We construct a welfare maximizing tolling regime, which eliminates congestion. All travelers located beyond a critical distance from the CBD gain from tolling, even when toll revenues are not redistributed, while nearby travelers lose. We discuss our results in the context of acceptability of tolling policies.     

Fuzzy modelling of static system optimum traffic assignment problem having multi origin-destination pair

Traffic congestion is an unpreventable problem to avoid in a transportation network and it has negative effects on traffic accident, time wasting, traffic delay and safety problem. Besides, in transportation networks, drivers do not want to deal with traffic jam while traversing between specified origin-destination pair. Therefore, traffic assignment (TA) is imperative to improve traffic management, transportation safety, time, and cost savings. System Optimum Traffic Assignment Problem (SOTAP) is a kind of TA model which aims to minimize the total system travel time on the network, and satisfies the flow conservation constraints. To model the SOTAP more realistically, the imprecise parameters can be taken as fuzzy. Therefore, in this paper, we focus on converting the conventional SOTAP to a fuzzy quadratic programming problem (QPP) which is named System Optimum Fuzzy Traffic Assignment Problem (SOFTAP). Here, link travel time is expressed with BPR function as generally used in the literature by converting to fuzzy except link-dependent parameters. Thus, the nonlinear objective function of SOFTAP is expressed in terms of fuzzy link flows and fuzzy link travel times. A solution approach from the literature is modified to the reconstructed SOFTAP.     

Evacuation based on spatio-temporal resilience with variable traffic demand

The efficient evacuation of people from dangerous areas is a key objective of emergency management. However, many emergencies give little to no advanced warning, leading to spontaneous evacuation with no time for planning or management. For large emergencies, destinations become less certain, with traffic demand imbalanced and concentrated on a few oversaturated routes familiar to evacuees. Ultimately, this leads to rapid congestion and delay on some routes, while others remain barely used, extending clearance times with an accumulating population at risk. In this study we address these issues through incorporating spatio-temporal traffic resilience dynamics into a destination choice model utilizing the available capacity of the overall network. We validate our model through a post-concert egress event. The results suggest that our method can reduce total egress times and average travel time by 20%–43% over the no-guidance condition. Our method can be used to estimate and quantify emergency conditions to optimally guide destinations and routing choice for evacuees and/or autonomously moving vehicles during evacuations.     

Mathematical analysis applied to school attendance areas

The objective of this paper is to develop a generalized mathematical model of pupil assignment within school districts. This model can then be used to examine various policies of student integration. Proposed bussing schemes, school location policies, educational parks, attendance boundaries, etc., can be tested for cost, travel time or other measures of efficiency. Extension to other areas of educational planning is feasible.

Mathematical programming techniques are used to assign resources (say school children) to facilities (say schools) subject to restrictions on facilities (say capacity limits) and resources (say a maximum travel time or a desirable range of school “mixtures”) so that a measure of performance, the “objective function” (say total cost or total time of travel) is optimized. The model is intended to allow examination of a wide range of objective functions and system constraints.