As noted by others, this is a problem with Road-hog123's detailing pack. However, you cannot just reinstall the pack - you must first delete the whole pack, and then install the latest version.
What is likely to have happened is that you have an older map installed which uses an older version of the pack. The newer version of the pack changes the way that the objects are textured, with new DDS textures with completely different mapping. Due to the weird way OMSI handles textures, if the old version is still installed it will instead load the original BMP textures which are incompatible with the newer models. That means that the wrong bits of the textures are loaded onto the models, which is why you're seeing brightly coloured traffic lights, for instance.
When you delete the pack you may find new problems with other, older maps you have installed - this is because those maps have not been kept up to date by their authors and use parts which are only available in the older packs. Unfortunately, without modifying the map files yourself to fix this (which is relatively simple), you cannot have maps using the old pack and maps using the new pack working at the same time on the same installation.