Merging overlapping lines into one line. QGIS

I have a shapefile with multiple perfectly overlapping lines. Each line represents traffic at a certain point in time. I would like my output to have only one line but with the attributes from all other lines. Each segment has 123 overlapping lines

Any hints on how I should approach this?

Answer

I had a similar problem and solved it with @lynxlynxlynx's suggestion. In my case I had a directed road network with traffic volumes as attribute and the goal was to obtain the total volume. Using the tool at Vector->Data Management Tools->Join attributes by location and the choosing 'equals' as the predicate, it was possible to obtain the sums (other options are also available).