基于ITS的解决城市道路交通拥堵的有效措施研究

城市道路交通拥堵已成为世界各国普遍存在的问题,严重影响着城市的经济建设、运转效率和人们的工作与生活。如何解决城市道路交通拥堵问题,越来越受到人们的重视。在明确我国城市道路交通概念、特征和城市道路交通拥堵涵义的基础上,提出了ITS是解决城市道路交通拥堵的有效治理措施的思路。     

城市道路建设中的交通组织与安全保障技术探讨

文章立足于城市道路建设的交通组织基本原理,首先从施工道路现状调查获取有关数据、针对占道路施工进行设计、施工交通组织方案设计来分析城市道路建设方案设计;接着阐述了城市交通建设交通组织方案的实施;最后还从制度、资金、技术等方面详细探讨城市道路建设中的交通组织与安全保障.     

广州市道路交通规划建设探讨

文章针对广州市道路系统规划的基本状况及存在的问题,结合国外城市道路交通规划建设及管理经验,提出了基于小尺度道路网、合理道路等级级配和快速路系统的城市道路交通规划建设优化措施及建议,为缓解城市交通拥堵提供理论依据。     

基于大数据的交叉口信号控制系统设计

平面交叉口作为交通冲突的集中点,是制约当前城市道路交通通行能力的瓶颈。文章基于大数据技术,构建一体化交叉口信号处理系统,针对现有设施改善道路交通状况,为解决道路交通问题带来新的思路。     

信息化是人车路一体化最重要的桥梁与纽带

本文在对比国内外高速公路动态限速信息标志设置、城市道路交通诱导信息和交通诱导设施整合实际案例的基础上,从国内外交通动静态信息一体化、交通信息与驾驶行为一体化以及路面交通诱导信息与车载导航信息、手机导航信息一体化角度进行阐述,对我国与发达国家在ITS发展方面存在的差距展开思考,为进一步明确我国ITS的发展方向提供建议和借鉴。     

城市道路交通设计思路及技术关键要点研究

为了满足城市居民的出行需求,提高城市道路交通设计水平,分析城市道路交通设计的特点和基本要求,提出城市道路交通设计思路和技术关键要点,以期为同类型设计工作提供参考。     

城市道路交通设计中存在的问题及改进措施

道路规划设计是保证城市生活舒适、布局美观的关键。良好的城市道路规划不仅能保证城市交通的发展还能促进城市市容建设。鉴于此,针对现代城市道路设计布局中存在的问题进行分析,并提出改进措施,可为相关城市道路交通设计提供参考。     

南宁市城市道路建设的影响因素分析

如何科学合理地进行城市道路网建设是目前城市建设的核心问题。文章以南宁市十二五期间城市道路网建设规划为例,介绍了城市道路建设影响因素的类别及内容,分析了交通基础设施建设、重大项目建设、旧城改造、管网建设、外围城镇发展等与城市道路路网建设的相互关系,并通过指标测算确定规划期内道路建设的合理规模。     

深莞惠都市圈道路网一体化发展对策研究

本文从都市圈一体化发展的角度,分析了深圳、东莞、惠州三地道路网发展现状、三市经济一体化和综合运输发展趋势,从完善一体化道路网基础设施、加强交通组织管理、提升综合服务能力、统一公路与城市道路的管理机构、健全道路网一体化法规政策等方面提出了深莞惠都市圈道路网一体化发展对策建议。     

城市道路设计交通分析及预测

交通量预测好坏直接关系到城市道路的使用和安全。结合城市道路设计实体工程,详细阐述了城市道路的限制交通调查与分析和交通量预测,为城市道路交通预测问题提供了思路和借鉴。     

Model,process, technique,and the good thing

The paper unpacks the planning process into its component parts: model, process, technique, and goals—the “good thing”. The paper advances the concept that planning, policy-making, and organizational restructuring can be analyzed under the same framework. Each of the four components is described and reductionist examples are presented to clarify the intention and to illustrate the technique that the transport analyst teams employ in their work. The examples cover both successes and failures. They point toward the enormous scientific task ahead for planning to become meaningful and relevant to the problems of today. Finally, in the frame of the willingness to pay, the paper puts forward a case for an institutional framework for a financially autonomous road administration. Similarly organized, administered, and managed entities are relevant also for other transport modes.

Space,money, life-stage,and the allocation of time

Demographic, socioeconomic, seasonal, and scheduling factors affect the allocation of time to various activities. This paper examines those variables through exploration of the 1990 Nationwide Personal Transportation Survey, which has been inverted to track activity duration. Two key issues are considered. First, how much can activity duration and frequency explain travel duration? The analysis shows activity duration has positive and significant effects on travel duration, supporting recent arguments in favor of activity based models. Second, which recent trend is the main culprit in the rise in travel: suburbanization, rising personal incomes, or female labor force participation? This paper examines the share of time within a 24-hour budget allocated to several primary activities: home, work, shop, and other. The data suggest that income and location have modest effects on time allocation compared with the loss of discretionary time due to working.

     

Walking frequency, cars, dogs, and the built environment

To explain walking propensity or frequency, empirical studies have generally used two sets of explanatory variables, namely, socio-demographic variables and built environment variables. They have generally shown that both socio-demographic characteristics and built environment characteristics are associated with walking propensity. We examine the traditional walkability variables that encompass density, mix of uses, and network connectivity in New Jersey, using a statewide sample including an oversample of Jersey City. We estimate a two-stage least squares model using a conditional mixed process that combines an ordered probit model of walking frequency in the second stage based on a truncated regression of car ownership in the first stage. Our results show that built environment variables have some small effects, mainly from better network connectivity associated with increased walking frequency. One of our key findings is that built environment features also work indirectly via how they influence car ownership. In general, we find sufficient evidence that suggests fewer cars are owned in areas with more walkable built environment features. The other key variable that we control for is whether a household owns a dog. This also proved to be strongly associated with walking suggesting that dog ownership is a necessary control variable to understand the frequency of walking.     

Poverty,policy, and public transportation

By all appearances, the circumstances surrounding employment and income distribution in the United States have remained notably the same over the past 30–40 years. At the same time, policies for improving the conditions of low-income persons have remained relatively unchanged. Relevant published accounts continue to cite poorly integrated residential and employment location patterns and poor public transportation service as critical obstacles to improving the economic and social conditions of low-income persons. The relationship between poverty and public transportation was researched extensively during the late 1960s and the early 1970s; however, little recognition has been given to these efforts by more recent research efforts. To learn from the past we should review public transportation policies from 1960 to 2000 to highlight federal policies that affected urban areas during this time period, especially in relation to low-income transportation mobility.     

Governing autonomous vehicles: emerging responses for safety,liability, privacy,cybersecurity, and industry risks

ABSTRACT

The benefits of autonomous vehicles (AVs) are widely acknowledged, but there are concerns about the extent of these benefits and AV risks and unintended consequences. In this article, we first examine AVs and different categories of the technological risks associated with them. We then explore strategies that can be adopted to address these risks, and explore emerging responses by governments for addressing AV risks. Our analyses reveal that, thus far, governments have in most instances avoided stringent measures in order to promote AV developments and the majority of responses are non-binding and focus on creating councils or working groups to better explore AV implications. The US has been active in introducing legislations to address issues related to privacy and cybersecurity. The UK and Germany, in particular, have enacted laws to address liability issues; other countries mostly acknowledge these issues, but have yet to implement specific strategies. To address privacy and cybersecurity risks strategies ranging from introduction or amendment of non-AV specific legislation to creating working groups have been adopted. Much less attention has been paid to issues such as environmental and employment risks, although a few governments have begun programmes to retrain workers who might be negatively affected.     

Activity sequencing,location, and formation of individual non-mandatory tours: application to the activity-based models for Columbus,Cincinnati, and Cleveland,OH

Most of the earlier activity based models (ABMs) largely relied on a tour-based modeling paradigm which explicitly predicts tour frequency and then adds details including stop frequency, order, and location of stops within each tour. The current study is part of new tour formation design framework for an ABM in which the underlying tour structure and the stop frequency within tours emerge from temporal, sequencing, and locational preferences of activities that the traveler intends to participate during the day. In order to do this, the study developed a modified rank-ordered logit (ROL) framework that is capable of modeling sequence, locations, as well as the underlying tour structure of all activity episodes simultaneously in an integrated manner. Model estimation with the household survey data, provided several important behavioral insights into underlying choices that drive tour formation. Specifically, the study uncovered pairwise ordering preferences among episodes of different activity purposes, clustering tendencies among episodes of same activity purpose, the impact of supply side activity opportunities on the location and sequence choice dimensions, and impedance effects (including distance and mode and time-of-day logsums) on location and tour break dimensions. The developed models are incorporated in the operational ABM structure adopted for three major cities (Columbus, Cleveland, and Cincinnati) in Ohio.     

Integrated scheduling of m-truck,m-drone,and m-depot constrained by time-window,drop-pickup,and m-visit using constraint programming

The idea of deploying unmanned aerial vehicles, also known as drones, for final-mile delivery in logistics operations has vitalized this new research stream. One conceivable scenario of using a drone in conjunction with a traditional delivery truck to distribute parcels is discussed in earlier literature and termed the parallel drone scheduling traveling salesman problem (PDSTSP). This study extends the problem by considering two different types of drone tasks: drop and pickup. After a drone completes a drop, the drone can either fly back to depot to deliver the next parcels or fly directly to another customer for pickup. Integrated scheduling of multiple depots hosting a fleet of trucks and a fleet of drones is further studied to achieve an operational excellence. A vehicle that travels near the boundary of the coverage area might be more effective to serve customers that belong to the neighboring depot. This problem is uniquely modeled as an unrelated parallel machine scheduling with sequence dependent setup, precedence-relationship, and reentrant, which gives us a framework to effectively consider those operational challenges. A constraint programming approach is proposed and tested with problem instances of m-truck, m-drone, m-depot, and hundred-customer distributed across an 8-mile square region.     

Adaptive traffic control system: Control strategy,prediction, resolution,and accuracy

Recent advances in traffic control methods have led to flexible control strategies for use in an adaptive traffic control system (ATCS). ATCS aims at controlling the imminent traffic, which is yet to arrive and hence not known perfectly. Therefore, volume prediction is an essential part. Associated with the prediction are two aspects: resolution and accuracy. Recent studies indicate a tradeoff between prediction resolution and accuracy: finer resolutions, larger errors. It is imperative to study the relationship and tradeoff between the control strategy, prediction resolution, and its associated error, which are crucial to the development of ATCS. This study investigates this relationship through an extensive simulation of scenarios in Hong Kong with a recently developed dynamic traffic control model, DISCO. Based on the Hong Kong scenarios conducted with DISCO, the major findings include: (i) the importance of resolution outweighs that of error; (ii) dynamic timing plans generally outperform time‐invariant timing plans; (iii) up to a certain extent, overestimated predictions lead to better results than underestimated predictions.     

Modeling the structural relationships among short-distance travel amounts,perceptions, affections,and desires

Using structural equation modeling, the relationships among travel amounts, perceptions, affections, and desires across five short-distance (one-way trips of less than 100 miles) travel categories (overall, commute, work/school-related, entertainment/social/recreation, and personal vehicle) are examined. The models are estimated using data collected in 1998 from more than 1300 working commuters in the San Francisco Bay Area. A cross-model analysis reveals three robust relationships, namely: (1) myriad measures of travel amounts work together to affect perceptions; (2) perceptions are consistently important in shaping desires; and (3) affections have a positive relationship with desires. The second finding suggests that two individuals who travel the same objective amount may not have the same desire to reduce their travel: how much individuals perceive their travel to be is important. The third point argues that the degree to which travel is enjoyed is a key determinant of shaping desires to reduce travel: the more travel is enjoyed, the less the desire to reduce it.