The team evaluated adding a complementary fixture to the VTU to allow assessment of TGMS accuracy under dynamic scenarios in a controlled laboratory environment. The fixture would dynamically move short railhead samples, providing the same rail deviation input to the optical sensors of the tested TGMS that the VTU is inputting to the rail vehicle. Researchers explored two potential concepts for the fixture, one based on a Stewart platform and the other using a set of linear motor actuators. The team found that the VTU fitted with the additional fixture can be used to validate TGMS systems in tangents with reasonable fidelity, despite the inability to input gage deviations. This concept also would not be able to evaluate the performance of TGMS systems in curves due to VTU’s inability to replicate centripetal accelerations and forces.