Hi Mike,
In my experience with the DOS OS on modern machines, VirtualBox or DOS-BOX are pretty good options when it comes to emulating the way DOS used to run and the hardware it used. Another mention is that there have been documented instances where certain CPUs operate at frequencies that make it *almost* incompatible when communicating with older devices due to a way that the frequency of the messages/signals on the line is timed.
If you have a specific question in getting the device to work with your software I may be able to help; but have no experience with traffic devices or infrastructure. Do you currently have any errors or is it just not recognizing your device?