Search

Weaving areas are one of the major highway facilities that have long been investigated by researchers. Their capacities are currently estimated based on the density 27 pc/km/ln. There is no specific reason why this method can produce accurate estimates. In addition, no data collection has been performed to validate them. This study develops a generalized capacity estimation model for weaving areas, which is applicable to the entire range of configurations of weaving areas, and compares the resulting capacity estimates to field estimates. The proposed methodology is based on gap acceptance theory and linear programming techniques. Speed and flow data over several days were obtained and analyzed to extract the capacity of three study sites along the QE Expressway, Toronto. It was found that, for the three study sites, the proposed methodology provides capacity estimates that are closer to the field-observed capacity values than the Highway Capacity Manual (2000) estimates. DOI: 10.1061(ASCE)0733-947X(2007)133:3(166) CE Database subject headings: Transportation engineering; Probabilistic methods.

In recent years, there has been a movement in local government regulations toward restricting the mounting height of on-premise, commercial signing and other roadside oriented signs. This has caused some concern among sign designers and fabricators that automobile drivers will have difficulty in seeing and reading many of these low profile signs. These potential visibility difficulties are caused by the presence of other vehicles; either those in front of the subject vehicle, those in the adjacent travel lane, or those traveling in the opposite direction; blocking the line of sight between the subject vehicle driver and any low-mounted, roadside sign. The objective of this research was to determine the probability of another automobile blocking the line of sight between the driver of a subject vehicle and an on-premise, low-mounted, roadside sign. The results indicated that this probability is a function of the position of the subject vehicle, the position(s) of one or more object vehicles, the volume of vehicles on the road, and the speed of the vehicles on the road. DOI: 10.1061/(ASCE)0733-947X(2006) (862) CE Database subject headings: Traffic speed, Traffic signs; Traffic volumes; Traffic characteristics; Computer aided simulation; Mathematical models.

In this paper, fire station redistricting of the Centre Region in Pennsylvania is considered to improve the efficiency of service and reflect the changing characteristics of the region. The problem is formulated as a multiobjective mathematical optimization problem. Due to difficulties in building a comprehensive analytical model and associated computational complexity, simulation, aided by, a geographic information systems application software package, is employed to solve the problem. The effectiveness of this analysis indicates that simulation can be used to solve problems of this nature and satisfactory districting plans can be generated efficiently. CE Database subject headings: Pennsylvania; Fire safety; Emergency services; Geographic information systems; Mathematical programming; Simulation.

This paper presents a new methodology for optimizing the signal timing controls of oversaturated networks based on the cell transmission model and a goal programming technique with multiple objectives. The proposed model accounts for intersection spillovers, equity in delays, and system throughputs. This new formulation is solved by genetic algorithms to obtain signal timing plans. A case study with a nine-intersection network and a comparison between the proposed model and the throughput-maximizing strategy are examined. It is found that the new method can efficiently minimize spillovers, balance delay equity, and provide reasonable system throughputs in their respective order for oversaturated networks. The result also indicates that the throughput-maximizing strategy does not always yield minimum spillovers for oversaturated networks and occasionally provides a larger difference in average link delay at a spillover intersection than the proposed model does. [ABSTRACT FROM PUBLISHER]

In this paper, fire station redistricting of the Centre Region in Pennsylvania is considered to improve the efficiency of service and reflect the changing characteristics of the region. The problem is formulated as a multiobjective mathematical optimization problem. Due to difficulties in building a comprehensive analytical model and associated computational complexity, simulation, aided by a geographic information systems application software package, is employed to solve the problem. The effectiveness of this analysis indicates that simulation can be used to solve problems of this nature and satisfactory districting plans can be generated efficiently. [ABSTRACT FROM AUTHOR]