I think that the answer to your question depends on the problem you have. Simulation programmes can be dived in different groups (microscopic, macroscopic, mesoscopic) based on the basic theoretical view as the basis for the description of traffic flow and its internal laws. So a recommendation could be very different if you are making research of intersection capacity (signalozed or non-signalized) or a network wide behaviour. Very seldom, if ever, one progma is able to describe all the aspects of traffic behavior. I therefore recommed you to go throuh several options and to analyze their functioning principles in relation to your problem.
See for example my paper: "Simulation of traffic systems - an overview". Journal of Geographic Information and Decision analysis. Vol. 3, No. 1. 1999, pp.1-8. Available at http://publish.uwo.ca/~jmalczew/gida_5/Pursula/Pursula.html.
Onather interesting paper might be:
Innamaa S. and Pursula M. (1998). Microscopic simulation of freeway traffic. Problems in widening the use of a simulation program. In. Rysgaard R. (Ed.). Proceedings of the Third International Symposium on Highway Capacity, Volume 1. Danish Road Directorate. Transportation Research Board: Committee on Highway Capcity and Quality of Service. Copenhagen, Denmark, June 1998. pp. 533-548.
The papers are 15 years old, but the basic principles and problems are valid also for new and more sophisticated simulation programs.
I think most are not answering correctly. She has MATLAB which will be interfaced with a traffic simulation. Labview is not the answer. I agree with Ravindra's second recommendation, VISSIM. VISSIM is an extremely powerful traffic microsimulation that can be linked with MATLAB through a COM interface. I have extensively used VISSIM and have linked the two together.
Tamas Tettamanti, 2013 has a white-paper with instructions and Matlab m-file example which I will attach. I've linked VISSIM's 30 day trial also.
The truth is that no software traffic simulation can they felt better than another. You can choose what you want, even free, it is important that you first make a calibration of all models. Otherwise I will not have what he simulates scientific value
Transmodeler. It does micro-meso-macro + simultaneously integrating all in one GIS platform so that planning tools can also be used like TRavel Demand etc. ... and it is the only GIS to perform matrix operations. Combined with TransCAD it's the only complete sim + complete transportation planning software and are integrated ...
I have used the Matlab-VISSIM COM interface to develop an automatic calibration process for the driving behavior parameters and I am satisfied with its performance. If you are interested in please see the paper in the link below: