How to add a mesh to a spline without deforming it?

Hey fellow humans,
i worked through this tutorial: Using Splines & Spline Components | Live Training | Unreal Engine - YouTube
Id like to know how i could add some meshes to it without getting deformed. The guard rails work pretty similar to it but they deform when the spline gets deformed.

For example when want to add some trafficlights i dont want them to bend around