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Weaving Area

A section of a highway where two or more vehicle flows must cross each other's path along a length of the freeway. Weaving areas are usually formed when merge areas are closely followed by diverging areas. They are also formed when a freeway on-ramp is followed by an off-ramp and the two are connected by a continuous auxiliary lane.

TRANSPORTATION ANALYSIS

Corridor analysis is a detailed analysis of a roadway performed for the purpose of obtaining the most accurate projected traffic volumes. The analysis takes into account existing traffic volumes, projected growth, and major traffic generating locations. A corridor analysis will yield projected traffic volumes for every movement allowed on a facility including main lane, ramp, frontage road, and turning volumes.

Design analysis is an analysis is used to determine the number of lanes required to deliver a specific LOS based on a forecast demand volume and given geometric design standards.

Operational analysis is an analytic evaluation of operations on an existing highway segment. The same type of analysis may be applied to evaluate probable operating conditions on a future facility. All traffic and roadway conditions must be specified, as well as traffic volumes. The typical situations which can be resolved through this type of analysis include the comparison of flow conditions for different volume levels and number of lanes. This type of analysis might also be used to establish the impacts of a change in the number of access points along a given section of multilane highway. Another typical application of an operational analysis might be to develop several alternative packages which would be used to improve the level of service or travel speed along a multilane highway.

Planning analysis is similar to Design analysis in that the number of lanes needed for a LOS is determined. However, the Planning Analysis requires much less input of detail, and it uses a very rough estimate for directional design hourly volume and using the design procedures.

Software for Traffic Simulation and Analysis

TRAF is a family of computer software traffic simulation models. It is an integrated software system which consists of five major component models and a variety of supporting programs. TRAF can be used to predict the effect of traffic engineering and Transportation System Management (TSM) strategies on a transportation system's operational performance. TRAF consists of an integrated set of simulation models which, in aggregate, represent the traffic environment. TRAF allows the user to "tailor" the selection of simulation models to specific needs and partition the analysis network into subnetworks, each of which is analyzed at a different level of detail. The TRAF software interfaces the various subnetworks. Components of TRAF are designed to represent traffic in different environments: urban streets (network or arterial), rural roads, and freeways at specific levels of detail (i.e., microscopic or macroscopic). Microscopic simulation models may be used to represent movements of individual vehicles, including influences of driver behavior. Macroscopic simulation models may be used to study changes in circulation patterns and gauge impacts or detailed

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