Combination of two Neural Networks

Question

I want to use an image segmentation program which use CNN and fuse it with another lane detection network.

Is it possible to train these two networks separately with their own datasets, and for real-time usage consider lane detection algorithm as the main network whenever algorithm does not detect lines use image segmentation algorithm to detect lines? I could not find any repo or paper for this and I am wondering is it possible at all?

I would really appreciate if someone can help me out with some information.