考虑二次停车的公交驻站时间分布拟合

公交车驻站时间是刻画公交站点服务状况的重要指标,也是影响交通网络运行效率的重要因素。在我国大多数城市,公交车在站点进行服务时常常会有二次停车的情况发生。想要改进站点服务状况,首先需要对公交驻站时间进行准确分析。本文研究有二次停车的公交车驻站时间分布,在实测数据的基础上,分别对第一次服务时间和第二次服务时间进行分布拟合,然后依据概率论的相关理论由两次服务时间的分布计算出公交车总服务时间(驻站时间)的概率分布。进一步由公交驻站时间概率密度函数推导出单辆公交平均在站服务时间的表达式,并且通过分析二次停车发生比例与公交第一次服务时长之间存在的制约关系,求解最佳二次停车比例。     

停车管理的基本理念与国际经验

本文从分析交通拥堵症结之一的停车问题出发,指出正确的指导理念是强化停车管理的关键,阐述了停车管理应遵循的基本理念,明确了停车立法、停车收费、停车管理机制的重要作用。以翔实的案例为依据,对巴西和日本两个国家的停车管理经验进行归纳,旨在为进一步推动我国停车管理事业提供建设性建议与思路。     

西安市停车现状研究分析与思考

停车管理是静态交通管理中一项非常重要的工作,处理好城市中心区的停车问题,对缓解道路交通拥挤,减少交通事故,提高道路通行能力等方面都有极其重要的意义。文章结合西安市停车现状,对停车管理中存在的问题进行了深入分析,并提出了相应的改善措施及建议。     

东莞市中心区停车改善规划研究

本文以东莞市中心区为案例,对中心区停车发展现状及问题进行了分析,结合东莞市停车发展所处的阶段,提出中心区停车改善目标、改善策略及改善原则,并从停车规划、建设、管理和收费等多个层面,提出东莞市中心区停车改善措施。     

解决城市“停车难”问题的思考与建议——以浙江省为例

当前，大部分国内城市现存泊位供给和有限的新建空间难以满足快速增长的停车需求，停车供给缺口日益扩大，虽然立体化、共享化等停车理念已趋于成熟，但仍需更具体有效的举措加以落实。本文以浙江为例，基于实地调研结果，从供需关系、执法监管、收费政策等方面分析总结城市停车发展代表性问题，进而结合现有典型案例做法，提出停车立体化改造、泊位共享、智慧监管等方面措施建议，为解决城市“停车难”问题提供借鉴参考。     

上海市停车需求管理政策导向及保障机制

本文阐述了停车需求管理的内涵和框架,指出上海市在中心区实施停车需求管理对缓解交通拥挤的必要性。借鉴国内外城市经验,探讨对上海市建立停车需求管理分区,通过差别化的供给、收费、管理实现有效的停车需求管理。     

关于城市智能停车信息系统建设的探讨

随着汽车逐渐走入百姓家庭,城市不仅出现了动态交通的严重阻塞,也出现了停车难、环境恶化等问题,城市停车问题已经成为影响城市交通可持续发展的瓶颈。为了提高停车管理水平,进行智能停车信息系统的研究与建设势在必行。本文通过简述停车信息系统应用情况的基础上,对如何进行城市智能停车信息系统的建设进行了探讨,同时阐明了发展智能停车信息系统的长远意义。     

停车管理信息系统设计研究

随着小汽车进入家庭，城市机动化水平进一步提高，我国大中城市停车难问题越来越严重。在北京、上海、广州等城市，特别是在高峰时段，一方面有大量汽车在拥挤的道路上寻找停车位，另一方面有部分停车场却因为诸多原因利用率很低，这样就造成了：由于寻找停车位而引起附加的不必要的交通出行，进一步加剧城市交通压力；增加燃料消耗和对城市环境产生污染；由此引起的不合法的停车行为，影响道路正常通行，易造成交通隐患；现有的停车场忙闲不均，停车潜力没有得到进一步开发。产生上述现象的原因，一方面是由于停车设施短缺和停车场位置布局…     

我国城市停车供给政策的评价与对策

我国城市高强度的开发模式、能源安全和环境等国情,决定了必须实施较低的停车供给水平,进行严格的停车需求管理,以配建停车为主,公共停车设施为辅,占道停车为补充。各城市及其不同区域,应根据土地使用性质和开发强度、公交发展水平等情况,差别化、精细化确定停车供给水平和政策。     

黄金周期间旅游景区停车管理对策

本文对黄金周期间八达岭长城景区的停车需求、时空分布和车辆类型等特点进行了分析,发现黄金周期间停车问题是临时性、突发性的大量停车需求与有限的停车泊位供应之间的矛盾。针对这种矛盾,具体从停车收费、停车信息服务、限制本市小型车数量和设置短途摆渡车四个方面提出了解决黄金周期间旅游景区的停车交通对策。     

Maximum car ownership under constraints of road capacity and parking space

This paper presents a model for determining the maximum number of cars by zones in view of the capacity of the road network and the number of parking spaces available. In other words, the proposed model is to examine whether existing road network and parking supply is capable of accommodating future zonal car ownership growth (or the reserve capacity in each zone); i.e. the potential maximum zonal car ownership growth that generates the road traffic within the network capacity and parking space constraints. In the proposed model, the vehicular trip production and attraction are dependent on the car ownership, available parking spaces and the accessibility measures by traffic zones. The model is formulated as a bi-level programming problem. The lower-level problem is an equilibrium trip distribution/assignment problem, while the upper-level problem is to maximize the sum of zonal car ownership by considering travellers’ route and destination choice behaviour and satisfying the network capacity and parking space constraints. A sensitivity analysis based heuristic algorithm is developed to solve the proposed bi-level car ownership problem and is illustrated with a numerical example.     

Road pricing — should and might it happen?

This article discusses recent attempts to implement a federally sponsored road pricing demonstration in the United States. It examines reasons for the attempts, pointing to several enduring traffic related problems; the greater effectiveness and flexibility of road pricing compared to other measures; and the proven feasibility of area licenses as in Singapore. The generally negative reaction of city decision-makers to road pricing is specified, particularly concerns about harm to businesses, interference with the right to travel and discrimination against the poor. Some lessons for further attempts at implementation of road pricing include more attention to contingency planning for worst possible outcomes; the design of parking permit programs which might lead the way to road pricing; and the selection of recreational rather than downtown sites for first attempts at innovative parking permit and road pricing schemes.     

A simple reservation and allocation model of shared parking lots

With increasing auto demands, efficient parking management is by no means less important than road traffic congestion control. This is due to shortages of parking spaces within the limited land areas of the city centers in many metropolises. The parking problem becomes an integrated part of traffic planning and management. On the other hand, it is a fact that many private parking spots are available during daytime in nearby residential compound because those residents drive their cars out to work. These temporarily vacant parking lots can be efficiently utilized to meet the parking demand of other drivers who are working at nearby locations or drivers who come for shopping or other activities. This paper proposes a framework and a simple model for embracing shared use of residential parking spaces between residents and public users. The proposed shared use is a winning strategy because it maximizes the use of private resources to benefit the community as a whole. It also creates a new business model enabled by the fast-growing mobile apps in our daily lives.     

A study on smart parking guidance algorithm

Parking problem becomes one of major issues in the city transportation management since the spatial resource of a city is limited and the parking cost is expensive. Lots of cars on the road should spend unnecessary time and consume energy during searching for parking due to limited parking space. To cope with these limitations and give more intelligent solutions to drivers in the selection of parking facility, this study proposes a smart parking guidance algorithm. The proposed algorithm supports drivers to find the most appropriate parking facility considering real-time status of parking facilities in a city. To suggest the most suitable parking facility, several factors such as driving distance to the guided parking facility, walking distance from the guided parking facility to destination, expected parking cost, and traffic congestion due to parking guidance, are considered in the proposed algorithm. To evaluate the effectiveness of the proposed algorithm, simulation tests have been carried out. The proposed algorithm helps to maximize the utilization of space resources of a city, and reduce unnecessary energy consumption and CO₂ emission of wandering cars since it is designed to control the utilization of parking facility efficiently and reduce traffic congestion due to parking space search.     

Characterization of incidents on an urban arterial road

The early warning of incidents on urban arterial roads in a congested city can reduce delay, accidents and pollutant emission. Freeway incident detection systems implemented in recent years may not be suitable for arterial incidents. Arterial incident detection is more difficult. The traffic flow on an arterial road is not conserved from the upstream end of a road link to the downstream end because urban traffic does turn in and out of side‐streets, car‐parks and local residences. Roadside friction such as kerbside parking and shopping traffic also tends to create apparent incidents which are in fact frequent and normal events. This paper develops a definition for an arterial incident and describes a case study on an arterial road in Melbourne, Australia. The study shows that detectors upstream of an incident are more useful for incident detection than downstream detectors. It also identifies occupancy and speed as the appropriate parameters to characterise and detect arterial incidents.     

Solving the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP): A model to explore the impacts of self-driving vehicles on urban mobility

Interest in vehicle automation has been growing in recent years, especially with the very visible Google car project. Although full automation is not yet a reality there has been significant research on the impacts of self-driving vehicles on traffic flows, mainly on interurban roads. However, little attention has been given to what could happen to urban mobility when all vehicles are automated. In this paper we propose a new method to study how replacing privately owned conventional vehicles with automated ones affects traffic delays and parking demand in a city. The model solves what we designate as the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP), which dynamically assigns family trips in their automated vehicles in an urban road network from a user equilibrium perspective where, in equilibrium, households with similar trips should have similar transport costs. Automation allows a vehicle to travel without passengers to satisfy multiple household trips and, if needed, to park itself in any of the network nodes to benefit from lower parking charges. Nonetheless, the empty trips can also represent added congestion in the network. The model was applied to a case study based on the city of Delft, the Netherlands. Several experiments were done, comparing scenarios where parking policies and value of travel time (VTT) are changed. The model shows good equilibrium convergence with a small difference between the general costs of traveling for similar families. We were able to conclude that vehicle automation reduces generalized transport costs, satisfies more trips by car and is associated with increased traffic congestion because empty vehicles have to be relocated. It is possible for a city to charge for all street parking and create free central parking lots that will keep total transport costs the same, or reduce them. However, this will add to congestion as traffic competes to access those central nodes. In a scenario where a lower VTT is experienced by the travelers, because of the added comfort of vehicle automation, the car mode share increases. Nevertheless this may help to reduce traffic congestion because some vehicles will reroute to satisfy trips which previously were not cost efficient to be done by car. Placing the free parking in the outskirts is less attractive due to the extra kilometers but with a lower VTT the same private vehicle demand would be attended with the advantage of freeing space in the city center.     

Parking policies in large cities in Germany

This article deals with highly motorized large West German cities of about 200,000 inhabitants and more, which usually provide reasonable public transport systems. Illegal parking with shares of about 40 to 50% of the total parking is widespread in the parking problem areas of those cities, especially in the inner-city residential and mixed-use areas. Parking spaces are demanded by residents, employees, customers and visitors, and by delivery and service traffic. The different characteristics of parking demands by different user groups are discussed. The total parking supply consists of public and private spaces. The share of private spaces is about 40 to 50% of the total parking spaces in German cities. The amount of car traffic generated by a parking space depends on parking duration and parking turnover, as well as on search traffic. So the change of a space from long-duration use of an employee to short-duration of customers — as often discussed in parking concepts — generates at least five-fold car traffic. The measurements and effects of parking control of public spaces as well as the parking regulations in zoning ordinances, restrictions on the construction of new private parking spaces and park-and-ride are discussed. Finally, a parking concept methodology — using the example of Frankfurt am Main — is discussed.     

System dynamics of urban traffic based on its parking-related-states

The urban parking and the urban traffic systems are essential components of the overall urban transportation structure. The short-term interactions between these two systems can be highly significant and influential to their individual performance. The urban parking system, for example, can affect the searching-for-parking traffic, influencing not only overall travel speeds in the network (traffic performance), but also total driven distance (environmental conditions). In turn, the traffic performance can also affect the time drivers spend searching for parking, and ultimately, parking usage. In this study, we propose a methodology to model macroscopically such interactions and evaluate their effects on urban congestion.The model is built on a matrix describing how, over time, vehicles in an urban area transition from one parking-related state to another. With this model it is possible to estimate, based on the traffic and parking demand as well as the parking supply, the amount of vehicles searching for parking, the amount of vehicles driving on the network but not searching for parking, and the amount of vehicles parked at any given time. More importantly, it is also possible to estimate the total (or average) time spent and distance driven within each of these states. Based on that, the model can be used to design and evaluate different parking policies, to improve (or optimize) the performance of both systems.A simple numerical example is provided to show possible applications of this type. Parking policies such as increasing parking supply or shortening the maximum parking duration allowed (i.e., time controls) are tested, and their effects on traffic are estimated. The preliminary results show that time control policies can alleviate the parking-caused traffic issues without the need for providing additional parking facilities. Results also show that parking policies that intend to reduce traffic delay may, at the same time, increase the driven distance and cause negative externalities. Hence, caution must be exercised and multiple traffic metrics should be evaluated before selecting these policies.Overall, this paper shows how the system dynamics of urban traffic, based on its parking-related-states, can be used to efficiently evaluate the urban traffic and parking systems macroscopically. The proposed model can be used to estimate both, how parking availability can affect traffic performance (e.g., average time searching for parking, number of cars searching for parking); and how different traffic conditions (e.g., travel speed, density in the system) can affect drivers ability to find parking. Moreover, the proposed model can be used to study multiple strategies or scenarios for traffic operations and control, transportation planning, land use planning, or parking management and operations.     

Parking permits management and optimal parking supply considering traffic emission cost

Given a many-to-one bi-modal transportation network where each origin is connected to the destination by a bottleneck-constrained highway and a parallel transit line, we investigate the parking permit management methods to minimize traffic time cost and traffic emission cost simultaneously. More importantly, the optimal supply of parking spots is also discussed in the policies of parking permit. First, we derive the total travel costs and emission costs for the two cases of sufficient and insufficient parking spot provisions at the destination. Second, we propose a bi-objective model and solve the Pareto optimal parking permit distribution, given a certain level of parking supply. Third, we investigate the optimal parking supply in the policy of parking permit distribution, with the objectives of minimizing both total travel cost and traffic emission. Fourth, we provide a model of optimizing parking supply, in the policy of free trading of parking permits. Finally, the numerical examples are presented to illustrate the effectiveness of these schemes, and the numerical results show that restricting parking supply at the city center could be efficient to reduce traffic emission.     

Tackling traffic congestion in Accra,Ghana: A road user's perspective

A fast emerging component of the urban transportation problem in cities of the Third World is the problem of traffic congestion. Rapid increases in car ownership coupled with poor land use planning, inadequate road space, lack of regulated parking systems, uneducated use of the road by pedestrians, and bad driving behavior of motorists have all combined to produce congestions comparable to those experienced in cities in the advanced parts of the world. Traffic management measures have been tried in some of the major cities such as road expansion and redistribution of land uses in city centers, but most have produced minimal results. It is recommended in this paper that city authorities adopt an integrated approach to congestion with emphasis on influencing the behavior of the road users.