Shunying Zhu

An Integrated System of Freeway Toll and Traffic Data Investigation: PDF417 Two-Dimensional Bar Code System

Aiming at the deficiency of being difficult to investigating and analyzing the traffic data by the toll data of freeway, utilizing the information storage technology of PDF417 two-dimensional (PDF417-2D) bar code, this paper sets up an integrated system of freeway toll and traffic data investigation, makes the encoding rules and content of record information which on the PDF417-2D bar code, and presents the procedure of toll and traffic data investigating. Combining Microsoft SQL Server data base management system and utilizing the data information of PDF417-2D bar code, this paper also proposed methods of freeway traffic volume OD investigation, creating OD matrix of entrances and exits, and calculating average traffic volume of section, which has offered a new approach to the unity of freeway toll and traffic data investigating and analyzing.

A New Method for Identifying Traffic Accident Black Spots Avoiding Statistical Influence

In order to overcome the defects of the existing methods for identifying the road traffic accident black spots which were influenced by the statistical scale and the statistical starting and end points, this paper presents a new method based on the gray correlation degree which is not influenced by the statistical scale. First, the road is divided into some cells which are the same length, and then, the longest cell length is confirmed according to the proportion of the cells in which the accident number is just one. Secondly, that composing the reference sequence makes use of the longest seriate cells in which all the adjacent cells have accidents. And then, the seriate cells are taken as the dynamic comparison sequence whose length is the same as the reference sequence. Thirdly, the gray correlation degrees are calculated by using the accident numbers of the two sequences. Then, the threshold value for identifying the traffic accident black spots can be confirmed according to the accumulative frequency distribution figure of grey correlation degree. Finally, the location and severity of the traffic accident black spots are ascertained by using the figure of the mileage - gray correlation degree. The results of the instance demonstrate that the method is feasible.

Literature review and prospect on the study of perceptual speed reduction

Speed and speed variance are related to the intensity and the number of traffic accidents, and the effective control on speed and speed variance is the key to enhance the road safety. Perceptual speed reduction technology is human-oriented, which has several merits such as the low cost, initiative and so on. The article explains the research significance of perceptual speed reduction; induces the concept of perceptual speed reduction; and analyzes the mechanism of its process and the basic characteristics of perceptual speed reduction, summarizes recent research status quo on this topic from several perspectives, such as hypothetical premise, experimental condition and method, conclusion and so on, meanwhile the paper carries on the classification of perceptual speed reduction, and analyzes advantages and disadvantages of each technique. Based on the above review, some important scientific questions which need farther study are raised and the future developing direction of perceptual speed reduction is discussed. Finally the research and the application prospect of perceptual speed reduction are given.

TRAFFIC ORGANIZATION OF FREEWAY TRUMPET INTERCHANGE RECONSTRUCTION AND EXPANSION WITH ALL RAMPS UNIMPEDED

Trumpet interchange is one of the most common types of interchange in the four-lane freeway and it is critical to organize traffic effectively during the reconstruction of it. The difficulties and key issues in traffic organization during reconstruction and expansion project of trumpet interchanges can be found out by analyzing the layout of ramps, traffic characteristics, reconstruction and expansion schemes and main construction technologies. Based on the idea of all ramps unimpeded, the general principles and methods of traffic organization of the trumpet interchange reconstruction and expansion project are put forward by considering the traffic characteristics, traffic volumes, reconstruction design proposals and construction period. The traffic organization during the trumpet interchange reconstruction and expansion project in Hohhot-Baotou freeway is analyzed, which may provide a useful reference for the traffic organization of the trumpet interchange reconstruction and expansion project in future. Trumpet interchange is one of the most common types of interchange in the freeway in our country, featured with simple form and only one Overpass Bridge and centralized toll stations. Taking Hohhot-Baotou freeway as an example, it has thirteen interchanges along 207 kilometers in length. Nine of them are trumpet interchange, which account for seventy percents. As the relation of the locations between the newly designed ramps and the old ones are complex, the quantities are large, the quantities of structures are immense and its hard to arrange the construction units, the trumpet interchange reconstruction and expansion project has a serious impact on the safety and smooth flow of traffic. Working out a reasonable plan of traffic organization during the construction of trumpet interchange reconstruction and expansion, could avoid traffic congestion and accidents. It could also make sure the good process of the project and reduce the bad effect on the society and economic.

Study of Diversion Point Settings Based on Tolerance and Satisfaction in Freeway Reconstruction and Expansion Project

Setting diversion point properly is the key to make the traffic organization and design proposal of road net diversion in reconstruction and expansion Project of freeway. Different functions of multistage diversion points in reconstruction and expansion project of highway are expatiated. According to the functions of diversion point at all levels, the node-sets which are used as diversion point are identified. Considering aspects of diverting conditions and drivers satisfaction, tolerance, diverted routing factor, and bypass cost are selected as analysis index. The necessity of diversion point settings are judged by using dynamic comprehensive evaluation method, the detailed proposal of multistage diversion point settings is obtained. Finally, setting multistage diversion point of hubao freeway reconstruction and expansion project is taken as an example for analyzing.

Variance Analysis of Factors That Affected Traffic Safety in Highway Work Zones

Highway work zones result in descent of road capacity and traffic-jam for part of lanes closed, and all of that would create safety concern. On the basis of crashes data which classified by different factors in Virginia highway work zones, the data that work zone crash levels and entire highway crash levels are analyzed with One-way analysis of variance (ANOVA) in SPSS. The data analysis in this study involved two major steps. First, identify the prominent variable that followed too closely and other 7 significant variables. Then, the 7 significant variables, corresponding entire highway crash levels and the prominent variant form 7 triple tables. One-way ANOVA is used to identify the secondary prominent factors such as lane change, speed too fast and inattentive drive. At last, investigate all the prominent variables using Grey Relational Analysis (GRA), and distinguish the relationship between different crashes type and drive behavior. The result of this study will provide theoretical basis for work zone safety guarantee technology. Owing to long-term operation or natural disaster, highway system will appear different degree of functions reduced and facility impaired. Numbers of work zones appeared to guarantee road normal operation. The major effect of work zones is descent road capacity for lane closure, which results in traffic-jam and delay and creating safety concern. In America, more than 700 fatal crashes happened, about 24000 injury crashes and 52000 property damages only due to crashes.

Study on the feasible traffic operation scheme of expressway reconstruction and extension project

The feasible traffic operation scheme of expressway reconstruction and extension project, based on the mode of maintaining traffic moving while project construction, is an important content of traffic organization design. Several typical two-lane or four-lane schemes are briefly introduced, which are suitable for expressway reconstruction and extension project with both sides widening in China. And combined with traffic organization and the construction technology, various types of feasible traffic operation schemes are given for SWOT analysis in three aspects such as traffic, engineering and social influence. Finally, through the analysis of the specific situation of the reconstruction and extension project, Hebei section of Beijing to Hong Kong and Macao expressway (G4) was studied.

Urban Traffic Mode Structure Optimization Based on Eco-Transportation

Urban eco-transportation system is the development direction of urban transportation system; urban traffic mode structure is an all-important factor that affects the realization of it. Despite a voluminous empirical research of traffic mode structure, most of them have failed to adequately consider the ecology problem. On the basis of satisfying all requirements of eco-transportation system, and according to the common problems such as traffic jam, serious traffic pollution, low efficiency of utilizing resources, this paper first proposes the idea of traffic mode structure optimization, it combines optimization with traffic planning; secondly, it analyzes the main objectives and constrains; finally, it establishes an fuzzy programming model of traffic mode optimization as a result of the uncertainty of transportation system in the future.

Design Theory for Speed Control by Using Increasing Edge Rate

Edge rate is an important source for driver’s perceptual speed. In this paper, the concept of edge rate and the theory about driver’s speed perception and control which based on edge rate were briefly described, and an introduction to the application effects of edge rate was also made. According to the concept of edge rate and Newton motion equation, a model fitting the comfortable uniformly decelerated motion was designed for speed control, which satisfied two restrictions, including the restriction of keeping edge rate increasing toward the directions of traffic and the restriction of time Weber’s law. Using the 3DMAX, the videos simulating car moving process on the freeway were made in which edge rate was a key manipulative parameter. Six males and two females took part in the experiments. 260 Subjectively Equal Speed experiments were implemented by using the Forced-Choice Method, and the reasonable bound of the edge rate value was educed by analyzing the experimental results. The Weber fraction was also determined through literature review. A case study was carried out in this paper, and the edge line spacing was calculated for controlling the speed from 120km/h down to 90km/h by the designed model. Comparison experiments were carried out between the condition when edge rate kept increasing and the condition when edge rate kept constant through the simulating video. The demonstration experiment indicated that the design mode of keeping edge rate increasing was more effective than the design mode of keeping edge rate constant.

Research on public parking lots planning based on traffic demand management

This paper introduced the concept of traffic demand management into the process of parking lots planning, and efforts were taken to achieve the traffic demand management concept which advocated go-aheadism, homeostasis and public transport priority. During the parking demand forecast stage, varieties in the transport structure and trip mode arising from the changes in dynamic traffic and demand management policies were taken into account, a model for forecasting parking demand was established whose results are more in line with actual parking needs. During parking lots distribution stage, the initiative influence of the parking lots was studied, and the principles for parking lots distribution were proposed out respectively from a macro strategic point of view, from the micro-strategic point of view and from the middle-level strategic point of view. According the parking service characteristic and the public transport priority rule in traffic demand management, a parking lots distribution optimization model was built under the consideration of dynamic traffic needs. The result can provide the theory foundation for public parking lots planning reasonably.