居民出行调查中的抽样技术研究

居民出行调查的数据是城市交通规划的基础,它的准确度直接影响着规划的质量。恰当的调查方法和抽样率对保证数据精度和节省费用至关重要。目前,我国绝大多数城市在进行居民出行调查时,根据国外经验来确定抽样率,理论依据不充分,无法估计调查数据的精度和预测数据的准确性。运用抽样技术理论,首先对居民出行调查中用的抽样方法和抽样率的计算做理论上的阐述,然后对常用的抽样率计算公式进行推导,并讨论其他相关问题,最后给出计算实例。     

基于有删失数据的失效率非参数估计方法

为解决当寿命分布的数学形式完全未知，而寿命试验数据又含有右删失数据的情况下，如何估计失效率函数的问题，推广运用密度结构估计的处理手段，根据极大似然的估计思想，在推推导出失效率函数估计的数学形式基础上，构造特殊的样条插值，给出了失效率函数的连续非参数估计。     

空心方块斜坡堤块体安放方法的试验研究

主要介绍了采用多孔和单孔空心方块摆放成斜坡堤和半圆形堤头的方法,在满足设计要求的堤体空隙率情况下,通过试验块体稳定性设计出这两种形状空心方块的摆放网格。     

列车结构变动对车站通过能力影响的研究

在车站技术设备及作业组织方法不改变的条件下,列车结构变动是影响车站通过能力的主要因素,对车站到发线通过能力影响的程度主要取决于各种列车占用到发线的时间差。当时间差较大,客货列车占线时间比较小,则增开旅客列车对货物列车的影响较小。在固定作业时间不变的条件下,无调列车比提高对技术站通过能力产生正面影响。通过分析增加旅客列车和提高无调列车比对车站通过能力的影响因子,推导出车站通过能力变化情况的计算公式。以内江车站通过能力为例计算表明,如果车站固定作业时间保持不变,无调列车比由11%提高到30%,则到发线能力较原来提高8.2%,增效显著。     

论超限超载运输的治理

公路运输超限超载危害巨大.在加强治理超限超载过程中存在一些困难和问题,需要采取有针对性的措施加以解决.对公路超限超载危害性、治理中存在的问题以及相应对策的分析研究,对于有效治理超限超载具有重要指导意义.     

Passenger rail in North America in the light of developments in Western Europe and Japan

Because of different geo‐demographic and economic conditions, the impact of the new passenger modes (road and air) on rail travel was much larger in North America than in Europe. In 1960s and 1970s, as the railway share of intercity traffic in North America shrunk to a negligible one or two percent, the passenger trains were abandoned by private railway companies and taken over by state organizations, which have continued to operate traditional trains and generate mounting losses. On the technology side, no attempts have been made to improve competitiveness of trains vis‐a‐vis automobiles and airplanes.

In Europe and Japan, the railways responded to the challenge by (i) upgrading the performance (speed) and comfort of traditional trains operating on existing tracks and (ii) developing trains which could, on short and intermediate range distances, compete successfully, in terms of speed and economy, with the road and air modes. The Japanese (Shinkansen trains) and French (TGV trains) experience clearly shows that trains operating on dedicated lines at average speeds of 150 to 200 km/hr provide a superior transportation service and economy on high‐traffic intercity routes of up to about 500 km length. In this paper the factors responsible for the present status of passenger rail in North America are analysed, the current policies in the U.S. and Canada are evaluated in the light of experience to date and developments abroad, and suggestions for a long‐term passenger rail policy are made. This includes examination of (i) the viability of continued subsidization of traditional train services, (ii) the viability of operation of faster trains on existing tracks, (iii) the scope for introduction of modern, fast trains on dedicated lines in high‐density, intercity corridors, (iv) the application of fast trains as access to major airports and integration of airports with fast intercity lines, and (v) the impact of energy (oil) consumption in transportation.

     

Quantitative assessment of effect of enforcement intensity on violation rates of vehicle weight and dimension regulations

A theory of upper bound limit describing the relationship between maximum possible violation rate as a function of the intensity of enforcement of vehicle weight and dimension regulations and indeed other transport administrative regulations is postulated. The model is an exponential function that determines the maximum violation rate for given inspection capacity. The constant of the function depends on the method of enforcement. The theory is demonstrated to be valid. It has potential for facilitating important policy issues relating to enforcement of transport administrative regulations and within the framework of infrastructure management to be addressed.

The relative effectiveness of enforcement methods is quantified by two parameters namely, the effectiveness index and the truckers’ relative perceived probability of detection. These parameters facilitate evaluation of the performance of various enforcement methods and operation strategies. It is found that patrol teams are, on average, 30 times as effective in detecting violations as continuously operated permanent weigh scales. High perceived detection probabilities are associated with high inspection capacities. To increase the perceived detection probability (reduce violation rates) therefore implies increasing the inspection capacity.     

基于竞争的高速铁路客运需求量预测

从铁路运输企业的角度，以市场竞争为导向，以提高铁路客运市场竞争力和综合经营效益为目标，从客流属性特征出发，对竞争条件下旅客运输需求进行分析，引入匹配因子和分担率的概念，以距离和旅客收入结构为交叉因素对分担率进行预测，构建了适应我国铁路客运需求预测理论体系，并以京广线为例对高速铁路在竞争条件下的客运需求量进行了合理预测．     

不同到达分布下双泊位快速公交车站使用效率仿真研究

通过VISSIM仿真软件,建立不同车头时距分布的双泊位快速公交车站仿真模型,构建车站泊位使用率的评价体系及相关仿真实验方法,通过仿真实验,可以分析不同车距时距分布对于双泊位快速公交车站不同泊位使用率的影响,对实践工作具有指导意义。