4.6 Analytical Simulations
There are a number of analytical simulation tools used for testing roadway designs. The tools can be used to test capacity for a system, intersection and signal timing performance, or general traffic flow performance evaluation for a road network. Some of the more common tools are: HCS, CORSIM, Synchro, SimTraffic, Transyt 7F and VISSIM. The tools are more commonly used for urban and high traffic road systems.
The simulations typically involve building a schematic representation of the roadway network. Many of the tools can use a CAD representation of the road design as a background for tracing the network. These typically import some 2D format such as DXF, which can be exported directly from Microstation. Some of these tools, most notably VISSIM, can import and use as a background a 3D model including texture maps. If a road model in Microstation were requested as the base for this type of simulation model, a typical pipeline for conversion of a Microstation model would be to export as VRML. The same issues that apply to optimization and export of a model to VRML outlined in sections 4.1 and 4.5 would apply to this process.