Urban Expressway Network Research Articles

Propagation of Improvement Effects of Critical Inter-city Link --- The Japanese Decadal Change of the Available Travel Routes ---

Abstract: Unlike the urban highway network, the inter-city network is composed of heterogeneous links of various speeds, costs and frequencies. Improvement of one airway link can possibly provide a new attractive travel route, such as an air connection route, as well as multi-modal route, including middle distance railway access. The improvement effect of a critical link may be propagated over the nation-wide network, unlimited to the direct neighbor connector of the improved link. How such propagation occurred in Japan between 1995 and 2005 is investigated. K-th shortest path search algorithm is applied to find the available set of routes. Remarkable changes in the Tohoku-Western Japan pairs are detected. This paper further analyzes the effects of the Shinkansen expansion to Hachinohe in 2002 on the service level of the available routes for those OD pairs, proving that there are strong multi-modal propagations on the air links at Sendai airport. Key Words: inter-city network, multi-modal routes, set of routes, Shinkansen

The Effect of Simultaneous Pavement Repair in Urban Highway Network

The repair range must be appropriately decided for effective pavement management. Pavement deterioration depends on its location, therefore it is optimal to repair only deteriorated place (independent repair policy), if life cycle cost is composed of only repair cost. However, sometimes, deteriorated place and not-deteriorated place are simultaneously repaired (simultaneous repair policy), because of traffic delay during repair activities. This paper consider traffic delay cost during pavement repair in life cycle cost, and describe the effect of simultaneous repair policy. As a result of case study implemented to Hanshin Expressway, simultaneous repair policy is optimal when traffic delay occurs, but independent repair policy is optimal when traffic delay does not occur. Simultaneous repair policy decreased 37.5 thousand billion yen per a year of its life cycle cost.

Risk Evaluation and Management for Road Maintenance on Urban Expressway Based on HEML (Hanshin Expressway Logic Model)

Hanshin Expressway is an urban expressway network accommodating more than 900, 000 vehicles per day. To sustain efficient and comfortable road traffic environment, Hanshin Expressway is performing various highway Rehabilitation and Maintenance (R&M) activities. The well-organized highway R&M activities (ex.; regular inspection, roadway cleaning, etc.) is fundamental for keeping traffic safety and provide road users with psychological satisfaction, but poor R&M may cause serious traffic accidents or defects. Due to the lacks of the sufficient budget for highway R&M, the highway administration bodies are always requested to reduce the expenditures for R&M activities.In this paper the logic model for R&M (named HELM; Hanshin Expressway Logic Model), which was developed by the Hanshin Expressway Corporation, is presented to administrate the whole system of R&M activities in an efficient way. The model will turn out to be the indispensable platform for the introduction of the R&M contracts with the outside sectors in a near future. Some evaluation indicators for policy models comprising HELM, which are expected to be monitored and evaluated throughout the implementation of the PDCA cycles, are also illustrated in the paper. This paper shows the methodology to formulate the criteria based on risk (probability×consequence) measurement for the risk management of the potholes, sands and pebbles, upon the pavement. The criteria presented in this paper can be estimated based upon the past record on highway patrol. And the paper presents the risk management diagrams for the highway patrol, by which the administrative bodies can efficiently design the optimal patrol frequency given the predetermined risk levels. The paper is concluded by summarizing the ongoing research agenda to improve the HELM throughout the PDCA cycles of the real R&M activities.

Part 1: Pavement Rehabilitation: Fast-Track Construction for Concrete Pavement Rehabilitation: California Urban Highway Network

This case study presents an innovative fast-track reconstruction approach applied to a heavily trafficked Long-Life (30-plus years) Pavement Rehabilitation Strategies (LLPRS) project on I-15 in Devore in Southern California. A 4.5-km stretch of badly damaged concrete truck lanes was rebuilt over two 215-h (approximately 9-day) periods with one-roadbed full closures with counterflow traffic and around-the-clock (24 h per day/ 7 days per week) construction operations. The same project would have taken 10 months to complete with traditional nighttime closures. State-of-practice technologies were adopted on this Rapid Rehab project to accelerate construction, mitigate traffic disruptions, and propagate project information. From the initial planning and design stages, engineers used CA4PRS (Construction Analysis for Pavement Rehabilitation Strategies) software incorporated with traffic simulation models to develop an optimal and economical rehabilitation scenario. Postconstruction data validated the preconstru...

An Analysis of the Effect of Information System at Merging Section Using Driving Simulator

In this Paper, the effect of information system at merging section of urban expressway network on driver's driving smoothness is examined, by utilizing a driving simulator system. Through the experiment of three types of the information system by 14 test drivers, we understand following three major results ;1) well-experience driver tends to prefer a guide-lamp system, and can possibly increase travel speed and can decrease the acceleration and deceleration at merging section, 2) lessexperience driver tends to over-react to a guide-lamp system, 3) a guide-lamp system sometimes has a undesirable effect in the case of system down.

Population Origin–Destination Estimation Using Automatic Vehicle Identification and Volume Data

The focus of this paper is the use of information from automatic vehicle identification (AVI) systems to help estimate short-term trip origin-destination (OD) matrices in an urban environment. In this paper, a method is proposed for using sample link choice proportions and sample OD matrix information derived from AVI data sampled from a portion of vehicles to estimate population OD matrices with the AVI data collection points acting as the origins and the destinations. This method is extended to estimate ramp-to-ramp freeway OD volumes. The value of such information is demonstrated using a large urban freeway network equipped with an AVI system. Based on a comparison of the OD estimate accuracies, with and without the AVI data, it was found that using AVI data in OD estimation improves significantly the accuracy of the OD matrix estimates.

Overview of Road Traffic Control Strategies

Traffic congestion in urban road and freeway networks leads to a strong degradation of the network infrastructure and accordingly reduced throughput which can be countered via suitable control measures and strategies. After illustrating the main reasons for infrastructure deterioration due to traffic congestion, a concise overview of proposed and implemented control strategies is provided for three areas: urban road networks, freeway networks and route guidance. The paper concludes with a brief discussion of future needs in this important technical area.

Review of road traffic control strategies

Traffic congestion in urban road and freeway networks leads to a strong degradation of the network infrastructure and accordingly reduced throughput, which can be countered via suitable control measures and strategies. After illustrating the main reasons for infrastructure deterioration due to traffic congestion, a comprehensive overview of proposed and implemented control strategies is provided for three areas: urban road networks, freeway networks, and route guidance. Selected application results, obtained from either simulation studies or field implementations, are briefly outlined to illustrate the impact of various control actions and strategies. The paper concludes with a brief discussion of future needs in this important technical area.

Calibration and Validation of Microscopic Traffic Simulation Tools: Stockholm Case Study

The calibration and validation approach and results from a case study applying the microscopic traffic simulation tool MITSIMLab to a mixed urban-freeway network in the Brunnsviken area in the north of Stockholm, Sweden, under congested traffic conditions are described. Two important components of the simulator were calibrated: driving behavior models and travel behavior components, including origin–destination flows and the route choice model. In the absence of detailed data, only aggregate data (i.e., speed and flow measurements at sensor locations) were available for calibration. Aggregate calibration uses simulation output, which is a result of the interaction among all components of the simulator. Therefore, it is, in general, impossible to identify the effect of individual models on traffic flow when using aggregate data. The calibration approach used takes these interactions into account by iteratively calibrating the different components to minimize the deviation between observed and simulated measurements. The calibrated MITSIMLab model was validated by comparing observed and simulated measurements: traffic flows at sensor locations, point-to-point travel times, and queue lengths. A second set of measurements, taken a year after the ones used for calibration, was used at this stage. Results of the validation are presented. Practical difficulties and limitations that may arise with application of the calibration and validation approach are discussed.

A Study on the Order of Expansion Projects for the Urban Highway Network

In case of expansion projects for the road network, we have to consider the influence on evaluation of the following project by the previous project implementation. But, this influence has not been considered onthe present cost-benefit analysis. So, in this study, targeting on the Hanshin Expressway, we searched three orders of expansion projects by the criterion of maximizing TENPV on the long-term, by the criterion of cost-benefit ratio, and bythe criterion of congestion rate. We, then, made characteristics clear their orders of expansion projects considering traffic congestion.

Modeling residential location choice in relation to housing location and road tolls on congested urban highway networks

We present a reformulation of the residential location submodel of the Integrated Model of Residential and Employment Location as a network equilibrium problem, thereby making travel costs by auto endogenous. The location of housing supply is examined as a welfare maximization problem for both user-optimal and system-optimal travel costs using concepts of bilevel programming. Finally, we briefly discuss how the employment submodel can be reformulated, and the entire model solved as a variational inequality problem.

A Study on the Real-time Ramp Control Method in Urban Highway Network

The present ramp control method of urban highway is not effective especially in the condition of heavy congestion because many operational constraints exist, The objective of this paper is to make a Real-time Ramp Control Method which is applicable to unstable traffic flow such as congestion. Peak load pricing is applied to this method in order to reduce the time that on-ramp is closed. In constructing such method, the main difficulty is the lack of algorithm which can quickly solve the optimization problem. In this paper, Genetic Algorithm is applied to help solve this particular problem.

Estimation of Spatially Distributed Effects of Urban Expressway Construction

It is expected that the urban expressway network broadly covering metropolitan areas can contribute to form the socioeconomic structure through its strongly connecting the zones in the areas with each other. This study is concerned with development of the ME & P typed land-use transport interaction model. This model can quantitatively estimate the spatial distribution of households and employments caused by the urban expressway construction. As a case study on the proposed model, spatially distributed effects of alternative levels of service by the network improvements are empirically compared with each other.

Developement of Dynamic On-Ramp Traffic Control Model for Urban Expressway Network

Because the traffic condition of urban expressway becomes worse with the expansion of network, effective trafficcontrol system becomes indispensable. In the near future, the operation of the advanced traffic information systemmakes it possible to obtain the dynamic and detailed traffic data. The propose of this study is to develope thedynamic on-ramp traffic control method based on the Linear Programming control model. The proposed modelconsiders unsteady-state of traffic demand and traffic flow. This model includes a sort of dynamic assignment modelin order to take driver's route choice on network into consideration. We built this model as the dynamic simulationmodel to apply it to the traffic control in emergency as well as on everyday control. This study testfies theperformance of this model and the influence of traffic control policy on network condition by some numericalexperiments.

Evaluation Techniques of Urban Expressway Networks through Colour Image

The Urban Expressways should be designed as a regional symbol to consider the landscape and the environment. The image is difficult to be described with linguistic expression as impacts given by regional mentality and surrounding factors. Therefore “the colour” is introduced to describe them in terms of information of planning. In the study, Neural Network (NN) Models are used to analyze the relation between “Environmental factors and the colour image” as well as “the colour image and degree of preference.” And also the evaluation of the road network is carried out as the combination of the colour images of consistent routes. The genetic algorithm involving NN model provides the future ideal image of the roads.

Automatic Congestion Detection (ACD) on Urban and Suburban Expressway Networks

This paper investigates freeway congestion and ACD method. An ACD approach through three phases is proposed. Different combinations between the ACD factors were tested (off-line) with traffic data from the operation system (SIRIUS) of the expressway network in Ile- de-France. The most effective combination detected an overall of 14 congestions (100% detection rate) with only 6 false alarms in the 10 days of test and a mean time to detect of 2 seconds.

An algorithm for the inflow control problem on urban freeway networks with user-optimal flows

A successive linear optimization method is proposed to efficiently solve the on-ramp traffic control problem on urban freeway networls with user-optimal flows. A linear approximation of the implicit, nonlinear capacity constraint is formulated using the first-order derivatives of the link flows with respect to input on-ramp flows. The derivative information required for the algorithm is based on the theory of sensitivity analysis for network equilibrium problems. The performance of the algorithm is illustrated and compared with the previous iterative linear programming and assignment algorithm using numerical examples.

Evaluation of Outside and Inside Expressway Ramps Based on Merging Probability

Japanese urban expressway networks contain not only the usual outside ramps, but also many inside ramps. Although the inside ramps do not block off adjacent and always‐expensive urban property, the design is less desirable operationally than one with outside ramps. This report describes a mathematical method to evaluate which of the two on‐ramp designs is better in terms of merging probability. Knowing the probability allows us to evaluate the operating conditions and capacities at merging area. A series of traffic surveys are conducted to accumulate data on the traffic‐flow characteristics of outside and inside ramps on the Hanshin Expressway network in Kobe, Japan. The headway distribution on the through lane and the acceptable gaps of the merging vehicles were measured from video tapes. The merging probabilities are calculated using those survey results. The results indicate higher merging probability for the outer parallel type. It is suggested that the inside‐ramp merging‐lane length should be longer...

A Formulation of On-ramp Traffic Control System with Route Guidance for Urban Expressway

This paper is concerned with the development of an improved on-ramp traffic control technique of urban expressway, particularly focusing on the formulation. Preparing for the future large scale urban expressway network, the conventional LP control method is extended so that it can consider the multiple routes between on/off ramps and the route choice behavior of the expressway user. The new method assumes that in future the users will have the detailed travel informations offered by the highly advanced traffic information systems, e.g. route guidance system. The proposed traffic control formulation combines the user equilibrium with the current LP traffic control formulation. It can determines the optimal inflow from each on-ramp so that the system effectiveness measures of the entire expressway network would be maximized, while the expressway user under control may choose the travel route using the provided informations. We discuss this mathematical formulation in detail and show the framework of solution procedure.

分割手法を用いた都市高速道路の流入制御の最適化

分割手法を用いた都市高速道路の流入制御の最適化