This would be perfect for 3 road/gravel/cx bikes. The rack was bought when first out - so about 14 years old, but it has been a great rack - it has been replaced as I'm needing to carry 2 wider MTBs which means the fitting of them becomes a jigsaw and I've not got the patience for it.
I've shamelessly pinched the image from Amazon as mine is currently in a storage room so I can't get pictures of it. Rack comes with a single key and all locks use the same key - I've 'upgraded' the bike clamps so they are all lockable, when this was first released, only the last rack had a lock on it (strangely), but each bike clamp can be locked. All electrics work and it is a 7-pin plug.
It has lived on the back of my car for quite some time, so probably needs a bit of a clean up of road muck, but otherwise, it is good to go.
The rack that has replaced it isn't as sturdy and the bikes wobble far more than they did on this one...once on the towball, the rack is solid.